QMessageBox 类

QMessageBox 类提供用于告知用户或向用户询问问题并接收答案的模态对话框。更多...

头：	#include <QMessageBox>
CMake:	find_package(Qt6 REQUIRED COMPONENTS Widgets) target_link_libraries(mytarget PRIVATE Qt6::Widgets)
qmake:	QT += widgets
继承：	QDialog

公共类型

enum	ButtonRole { InvalidRole, AcceptRole, RejectRole, DestructiveRole, ActionRole, …, ResetRole }
enum	图标 { NoIcon, Question, Information, Warning, Critical }
`(从 6.6 起)` enum class	Option { DontUseNativeDialog }
flags	Options
enum	StandardButton { Ok, Open, Save, Cancel, Close, …, ButtonMask }
flags	StandardButtons

特性

detailedText : QString
icon : Icon
iconPixmap : QPixmap
informativeText : QString
(从 6.6 起) options : Options

standardButtons : StandardButtons
text : QString
textFormat : Qt::TextFormat
textInteractionFlags : Qt::TextInteractionFlags

公共函数

	QMessageBox (QWidget * parent = nullptr)
	QMessageBox (QMessageBox::Icon icon , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = NoButton, QWidget * parent = nullptr, Qt::WindowFlags f = Qt::Dialog \| Qt::MSWindowsFixedSizeDialogHint)
virtual	~QMessageBox ()
void	addButton (QAbstractButton * button , QMessageBox::ButtonRole role )
QPushButton *	addButton (const QString & text , QMessageBox::ButtonRole role )
QPushButton *	addButton (QMessageBox::StandardButton button )
QAbstractButton *	button (QMessageBox::StandardButton which ) const
QMessageBox::ButtonRole	buttonRole (QAbstractButton * button ) const
QList<QAbstractButton *>	buttons () const
QCheckBox *	checkBox () const
QAbstractButton *	clickedButton () const
QPushButton *	defaultButton () const
QString	detailedText () const
QAbstractButton *	escapeButton () const
QMessageBox::Icon	icon () const
QPixmap	iconPixmap () const
QString	informativeText () const
void	open (QObject * receiver , const char * member )
QMessageBox::Options	options () const
void	removeButton (QAbstractButton * button )
void	setCheckBox (QCheckBox * cb )
void	setDefaultButton (QPushButton * button )
void	setDefaultButton (QMessageBox::StandardButton button )
void	setDetailedText (const QString & text )
void	setEscapeButton (QAbstractButton * button )
void	setEscapeButton (QMessageBox::StandardButton button )
void	setIcon (QMessageBox::Icon)
void	setIconPixmap (const QPixmap & pixmap )
void	setInformativeText (const QString & text )
`(从 6.6 起)` void	setOption (QMessageBox::Option option , bool on = true)
void	setOptions (QMessageBox::Options options )
void	setStandardButtons (QMessageBox::StandardButtons buttons )
void	setText (const QString & text )
void	setTextFormat (Qt::TextFormat format )
void	setTextInteractionFlags (Qt::TextInteractionFlags flags )
void	setWindowModality (Qt::WindowModality windowModality )
void	setWindowTitle (const QString & title )
QMessageBox::StandardButton	standardButton (QAbstractButton * button ) const
QMessageBox::StandardButtons	standardButtons () const
`(从 6.6 起)` bool	testOption (QMessageBox::Option option ) const
QString	text () const
Qt::TextFormat	textFormat () const
Qt::TextInteractionFlags	textInteractionFlags () const

公共槽

virtual int

exec () override

信号

void	buttonClicked (QAbstractButton * button )

静态公共成员

void	about (QWidget * parent , const QString & title , const QString & text )
void	aboutQt (QWidget * parent , const QString & title = QString())
QMessageBox::StandardButton	critical (QWidget * parent , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = Ok, QMessageBox::StandardButton defaultButton = NoButton)
QMessageBox::StandardButton	information (QWidget * parent , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = Ok, QMessageBox::StandardButton defaultButton = NoButton)
QMessageBox::StandardButton	question (QWidget * parent , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = StandardButtons(Yes \| No), QMessageBox::StandardButton defaultButton = NoButton)
QMessageBox::StandardButton	warning (QWidget * parent , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = Ok, QMessageBox::StandardButton defaultButton = NoButton)

重实现保护函数

virtual void	changeEvent (QEvent * ev ) override
virtual void	closeEvent (QCloseEvent * e ) override
virtual bool	event (QEvent * e ) override
virtual void	keyPressEvent (QKeyEvent * e ) override
virtual void	resizeEvent (QResizeEvent * event ) override
virtual void	showEvent (QShowEvent * e ) override

宏

QT_REQUIRE_VERSION (int argc , char ** argv , const char * version )

详细描述

消息框显示首要 text 以向用户发出状况警报，情报文本 to further explain the situation, and an optional 细节文本 to provide even more data if the user requests it.

A message box can also display an icon and 标准按钮为接受用户响应。

为使用 QMessageBox 提供了 2 个 API：基于特性的 API 和静态函数。调用某一静态函数方式更简单，但它不如使用基于特性的 API 灵活，且结果情报较少。推荐使用基于属性的 API。

基于特性的 API

To use the property-based API, construct an instance of QMessageBox, set the desired properties, and call exec () to show the message. The simplest configuration is to set only the 消息文本特性。

QMessageBox msgBox;
msgBox.setText("The document has been modified.");
msgBox.exec();

用户必须点击 OK button to dismiss the message box. The rest of the GUI is blocked until the message box is dismissed.

A better approach than just alerting the user to an event is to also ask the user what to do about it.

设置标准按钮 property to the set of buttons you want as the set of user responses. The buttons are specified by combining values from StandardButtons using the bitwise OR operator. The display order for the buttons is platform-dependent. For example, on Windows, Save is displayed to the left of Cancel , whereas on macOS, the order is reversed. Mark one of your standard buttons to be your 默认按钮 .

The 情报文本 property can be used to add additional context to help the user choose the appropriate action.

QMessageBox msgBox;
msgBox.setText("The document has been modified.");
msgBox.setInformativeText("Do you want to save your changes?");
msgBox.setStandardButtons(QMessageBox::Save | QMessageBox::Discard | QMessageBox::Cancel);
msgBox.setDefaultButton(QMessageBox::Save);
int ret = msgBox.exec();

The exec () 槽返回 StandardButtons value of the button that was clicked.

switch (ret) {
  case QMessageBox::Save:
      // Save was clicked
      break;
  case QMessageBox::Discard:
      // Don't Save was clicked
      break;
  case QMessageBox::Cancel:
      // Cancel was clicked
      break;
  default:
      // should never be reached
      break;
}

To give the user more information to help them choose the appropriate, action, set the 细节文本 property. Depending on the platform the 细节文本 , may require the user to click a Show Details... button to be shown.

点击 Show Details... button displays the detailed text.

富文本和文本格式特性

The 细节文本 property is always interpreted as plain text. The main text and 情报文本 properties can be either plain text or rich text. These strings are interpreted according to the setting of the 文本格式 property. The default setting is auto-text .

Note that for some plain text strings containing XML meta-characters, the auto-text rich text detection test may fail causing your plain text string to be interpreted incorrectly as rich text. In these rare cases, use Qt::convertFromPlainText () to convert your plain text string to a visually equivalent rich text string, or set the 文本格式 property explicitly with setTextFormat ().

严重级别、图标和像素图特性

QMessageBox supports four predefined message severity levels, or message types, which really only differ in the predefined icon they each show. Specify one of the four predefined message types by setting the icon property to one of the 预定义图标 . The following rules are guidelines:

	询问	For asking a question during normal operations.
	信息	For reporting information about normal operations.
	警告	For reporting non-critical errors.
	危急	For reporting critical errors.

预定义图标 are not defined by QMessageBox, but provided by the style. The default value is No Icon . The message boxes are otherwise the same for all cases. When using a standard icon, use the one recommended in the table, or use the one recommended by the style guidelines for your platform. If none of the standard icons is right for your message box, you can use a custom icon by setting the icon pixmap property instead of setting the icon 特性。

In summary, to set an icon, use either setIcon () for one of the standard icons, or setIconPixmap () for a custom icon.

静态函数 API

Building message boxes with the static functions API, although convenient, is less flexible than using the property-based API, because the static function signatures lack parameters for setting the 情报文本 and 细节文本 properties. One work-around for this has been to use the title parameter as the message box main text and the text parameter as the message box informative text. Because this has the obvious drawback of making a less readable message box, platform guidelines do not recommend it. The Microsoft Windows User Interface Guidelines recommend using the 应用程序名称作为窗口标题 , which means that if you have an informative text in addition to your main text, you must concatenate it to the text 参数。

Note that the static function signatures have changed with respect to their button parameters, which are now used to set the 标准按钮和默认按钮 .

Static functions are available for creating information (), question (), warning ()，和 critical () message boxes.

int ret = QMessageBox::warning(this, tr("My Application"),
                               tr("The document has been modified.\n"
                                  "Do you want to save your changes?"),
                               QMessageBox::Save | QMessageBox::Discard
                               | QMessageBox::Cancel,
                               QMessageBox::Save);

The 标准对话框 example shows how to use QMessageBox and the other built-in Qt dialogs.

高级用法

若标准按钮 are not flexible enough for your message box, you can use the addButton () overload that takes a text and a ButtonRole to add custom buttons. The ButtonRole is used by QMessageBox to determine the ordering of the buttons on screen (which varies according to the platform). You can test the value of clickedButton () after calling exec (). For example,

QMessageBox msgBox;
QPushButton *connectButton = msgBox.addButton(tr("Connect"), QMessageBox::ActionRole);
QPushButton *abortButton = msgBox.addButton(QMessageBox::Abort);
msgBox.exec();
if (msgBox.clickedButton() == connectButton) {
    // connect
} else if (msgBox.clickedButton() == abortButton) {
    // abort
}

默认键和 Esc 键

The default button (i.e., the button activated when Enter is pressed) can be specified using setDefaultButton (). If a default button is not specified, QMessageBox tries to find one based on the button roles of the buttons used in the message box.

The escape button (the button activated when Esc is pressed) can be specified using setEscapeButton (). If an escape button is not specified, QMessageBox tries to find one using these rules:

If there is only one button, it is the button activated when Esc is pressed.
若有 Cancel button, it is the button activated when Esc is pressed.
If there is exactly one button having either the Reject role 或 the No role , it is the button activated when Esc is pressed.

When an escape button can't be determined using these rules, pressing Esc 不起作用。

另请参阅 QDialogButtonBox and 标准对话框范例 .

成员类型文档编制

enum QMessageBox:: ButtonRole

This enum describes the roles that can be used to describe buttons in the button box. Combinations of these roles are as flags used to describe different aspects of their behavior.

常量	值	描述
`QMessageBox::InvalidRole`	`-1`	按钮无效。
`QMessageBox::AcceptRole`	`0`	Clicking the button causes the dialog to be accepted (e.g. OK).
`QMessageBox::RejectRole`	`1`	Clicking the button causes the dialog to be rejected (e.g. Cancel).
`QMessageBox::DestructiveRole`	`2`	Clicking the button causes a destructive change (e.g. for Discarding Changes) and closes the dialog.
`QMessageBox::ActionRole`	`3`	点击按钮导致对话框中元素改变。
`QMessageBox::HelpRole`	`4`	可以点击按钮以请求帮助。
`QMessageBox::YesRole`	`5`	The button is a "Yes"-like button.
`QMessageBox::NoRole`	`6`	The button is a "No"-like button.
`QMessageBox::ApplyRole`	`8`	The button applies current changes.
`QMessageBox::ResetRole`	`7`	The button resets the dialog's fields to default values.

另请参阅 StandardButton .

enum QMessageBox:: 图标

This enum has the following values:

常量	值	描述
`QMessageBox::NoIcon`	`0`	the message box does not have any icon.
`QMessageBox::Question`	`4`	an icon indicating that the message is asking a question.
`QMessageBox::Information`	`1`	an icon indicating that the message is nothing out of the ordinary.
`QMessageBox::Warning`	`2`	an icon indicating that the message is a warning, but can be dealt with.
`QMessageBox::Critical`	`3`	an icon indicating that the message represents a critical problem.

`[since 6.6]` enum class QMessageBox:: Option
flags QMessageBox:: Options

常量	值	描述
`QMessageBox::Option::DontUseNativeDialog`	`0x00000001`	Don't use the native message dialog.

该枚举在 Qt 6.6 引入。

Options 类型是 typedef 对于 QFlags <Option>。它存储 Option 值的 OR 组合。

enum QMessageBox:: StandardButton
flags QMessageBox:: StandardButtons

These enums describe flags for standard buttons. Each button has a defined ButtonRole .

常量	值	描述
`QMessageBox::Ok`	`0x00000400`	An "OK" button defined with the AcceptRole .
`QMessageBox::Open`	`0x00002000`	An "Open" button defined with the AcceptRole .
`QMessageBox::Save`	`0x00000800`	A "Save" button defined with the AcceptRole .
`QMessageBox::Cancel`	`0x00400000`	A "Cancel" button defined with the RejectRole .
`QMessageBox::Close`	`0x00200000`	A "Close" button defined with the RejectRole .
`QMessageBox::Discard`	`0x00800000`	A "Discard" or "Don't Save" button, depending on the platform, defined with the DestructiveRole .
`QMessageBox::Apply`	`0x02000000`	An "Apply" button defined with the ApplyRole .
`QMessageBox::Reset`	`0x04000000`	A "Reset" button defined with the ResetRole .
`QMessageBox::RestoreDefaults`	`0x08000000`	A "Restore Defaults" button defined with the ResetRole .
`QMessageBox::Help`	`0x01000000`	A "Help" button defined with the HelpRole .
`QMessageBox::SaveAll`	`0x00001000`	A "Save All" button defined with the AcceptRole .
`QMessageBox::Yes`	`0x00004000`	A "Yes" button defined with the YesRole .
`QMessageBox::YesToAll`	`0x00008000`	A "Yes to All" button defined with the YesRole .
`QMessageBox::No`	`0x00010000`	A "No" button defined with the NoRole .
`QMessageBox::NoToAll`	`0x00020000`	A "No to All" button defined with the NoRole .
`QMessageBox::Abort`	`0x00040000`	An "Abort" button defined with the RejectRole .
`QMessageBox::Retry`	`0x00080000`	A "Retry" button defined with the AcceptRole .
`QMessageBox::Ignore`	`0x00100000`	An "Ignore" button defined with the AcceptRole .
`QMessageBox::NoButton`	`0x00000000`	无效按钮。

以下值已过时：

常量	值	描述
`QMessageBox::YesAll`	`YesToAll`	使用 YesToAll 代替。
`QMessageBox::NoAll`	`NoToAll`	使用 NoToAll 代替。
`QMessageBox::Default`	`0x00000100`	使用 `defaultButton` argument of information (), warning (), etc. instead, or call setDefaultButton ().
`QMessageBox::Escape`	`0x00000200`	调用 setEscapeButton () 代替。
`QMessageBox::FlagMask`	`0x00000300`
`QMessageBox::ButtonMask`	`~FlagMask`

StandardButtons 类型是 typedef 对于 QFlags <StandardButton>. It stores an OR combination of StandardButton values.

另请参阅 ButtonRole and standardButtons .

特性文档编制

detailedText : QString

This property holds the text to be displayed in the details area.

The text will be interpreted as a plain text.

默认情况下，此特性包含空字符串。

访问函数：

QString	detailedText () const
void	setDetailedText (const QString & text )

另请参阅 QMessageBox::text and QMessageBox::informativeText .

icon : 图标

此特性保持消息框的图标

The icon of the message box can be specified with one of the values:

默认为 QMessageBox::NoIcon .

The pixmap used to display the actual icon depends on the current GUI style . You can also set a custom pixmap for the icon by setting the icon pixmap 特性。

访问函数：

QMessageBox::Icon	icon () const
void	setIcon (QMessageBox::Icon)

另请参阅 iconPixmap .

iconPixmap : QPixmap

此特性保持当前图标

The icon currently used by the message box. Note that it's often hard to draw one pixmap that looks appropriate in all GUI styles; you may want to supply a different pixmap for each platform.

By default, this property is undefined.

访问函数：

QPixmap	iconPixmap () const
void	setIconPixmap (const QPixmap & pixmap )

另请参阅 icon .

informativeText : QString

This property holds the informative text that provides a fuller description for the message

Informative text can be used to expand upon the text () to give more information to the user, for example describing the consequences of the situation, or suggestion alternative solutions.

默认情况下，此特性包含空字符串。

访问函数：

QString	informativeText () const
void	setInformativeText (const QString & text )

另请参阅 QMessageBox::text and QMessageBox::detailedText .

`[since 6.6]` options : Options

Options that affect the look and feel of the dialog.

By default, these options are disabled.

The option Option::DontUseNativeDialog should be set before changing dialog properties or showing the dialog.

Setting options while the dialog is visible is not guaranteed to have an immediate effect on the dialog.

设置选项在改变其它特性后，可能导致这些值不起作用。

该特性在 Qt 6.6 引入。

访问函数：

QMessageBox::Options	options () const
void	setOptions (QMessageBox::Options options )

另请参阅 setOption () 和 testOption ().

standardButtons : StandardButtons

消息框中的标准按钮集合

This property controls which standard buttons are used by the message box.

默认情况下，此特性不包含标准按钮。

访问函数：

QMessageBox::StandardButtons	standardButtons () const
void	setStandardButtons (QMessageBox::StandardButtons buttons )

另请参阅 addButton ().

text : QString

This property holds the message box text to be displayed.

The text should be a brief sentence or phrase that describes the situation, ideally formulated as a neutral statement, or a call-to-action question.

The text will be interpreted either as a plain text or as rich text, depending on the text format setting ( QMessageBox::textFormat ). The default setting is Qt::AutoText , i.e., the message box will try to auto-detect the format of the text.

The default value of this property is an empty string.

访问函数：

QString	text () const
void	setText (const QString & text )

另请参阅 textFormat , QMessageBox::informativeText ，和 QMessageBox::detailedText .

textFormat : Qt::TextFormat

This property holds the format of the text displayed by the message box

The current text format used by the message box. See the Qt::TextFormat 枚举了解可能选项的解释。

默认格式为 Qt::AutoText .

访问函数：

Qt::TextFormat	textFormat () const
void	setTextFormat (Qt::TextFormat format )

另请参阅 setText ().

textInteractionFlags : Qt::TextInteractionFlags

Specifies how the label of the message box should interact with user input.

默认值取决于样式。

访问函数：

Qt::TextInteractionFlags	textInteractionFlags () const
void	setTextInteractionFlags (Qt::TextInteractionFlags flags )

另请参阅 QStyle::SH_MessageBox_TextInteractionFlags .

成员函数文档编制

`[explicit]` QMessageBox:: QMessageBox ( QWidget * parent = nullptr)

Constructs an 应用程序模态 message box with no text and no buttons. parent 被传递给 QDialog 构造函数。

The window modality can be overridden via setWindowModality () 先于调用 show ().

注意： 使用 open () 或 exec () to show the message box affects the window modality. Please see the detailed documentation for each function for more information.

On macOS, if you want your message box to appear as a Qt::Sheet of its parent , set the message box's window modality to Qt::WindowModal or use open (). Otherwise, the message box will be a standard dialog.

另请参阅 setWindowTitle (), setText (), setIcon (), setStandardButtons ()，和 setWindowModality ().

QMessageBox:: QMessageBox ( QMessageBox::Icon icon , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = NoButton, QWidget * parent = nullptr, Qt::WindowFlags f = Qt::Dialog | Qt::MSWindowsFixedSizeDialogHint)

Constructs an 应用程序模态 message box with the given icon , title , text , and standard buttons . Standard or custom buttons can be added at any time using addButton ()。 parent and f 自变量被传递给 QDialog 构造函数。

The window modality can be overridden via setWindowModality () 先于调用 show ().

注意： 使用 open () 或 exec () to show the message box affects the window modality. Please see the detailed documentation for each function for more information.

在 macOS，若 parent 不是 nullptr and you want your message box to appear as a Qt::Sheet of that parent, set the message box's window modality to Qt::WindowModal (default). Otherwise, the message box will be a standard dialog.

另请参阅 setWindowTitle (), setText (), setIcon (), setStandardButtons ()，和 setWindowModality ().

`[virtual noexcept]` QMessageBox:: ~QMessageBox ()

销毁消息框。

`[static]` void QMessageBox:: about ( QWidget * parent , const QString & title , const QString & text )

Displays a simple about box with title title 和文本 text . The about box's parent is parent .

about() looks for a suitable icon in four locations:

It prefers parent->icon () if that exists.
If not, it tries the top-level widget containing parent .
If that fails, it tries the active window.
As a last resort it uses the Information icon.

The about box has a single button labelled "OK".

On macOS, the about box is popped up as a modeless window; on other platforms, it is currently application modal.

另请参阅 QWidget::windowIcon () 和 QApplication::activeWindow ().

`[static]` void QMessageBox:: aboutQt ( QWidget * parent , const QString & title = QString())

Displays a simple message box about Qt, with the given title and centered over parent (if parent 不是 nullptr ). The message includes the version number of Qt being used by the application.

这很有用，对于包括帮助菜单的应用程序，如展示在菜单范例。

QApplication provides this functionality as a slot.

On macOS, the aboutQt box is popped up as a modeless window; on other platforms, it is currently application modal.

另请参阅 QApplication::aboutQt ().

void QMessageBox:: addButton ( QAbstractButton * button , QMessageBox::ButtonRole role )

添加给定 button to the message box with the specified role .

另请参阅 removeButton (), button ()，和 setStandardButtons ().

QPushButton QMessageBox:: addButton (const QString & text* , QMessageBox::ButtonRole role )

这是重载函数。

Creates a button with the given text , adds it to the message box for the specified role , and returns it.

QPushButton QMessageBox:: addButton ( QMessageBox::StandardButton button* )

这是重载函数。

添加标准 button to the message box if it is valid to do so, and returns the push button.

另请参阅 setStandardButtons ().

QAbstractButton QMessageBox:: button ( QMessageBox::StandardButton which* ) const

Returns a pointer corresponding to the standard button which ，或 nullptr if the standard button doesn't exist in this message box.

注意： Modifying the properties of the returned button may not be reflected in native implementations of the message dialog. To customize dialog buttons add a custom button or button title instead, or set the Option::DontUseNativeDialog 选项。

另请参阅 standardButtons and standardButton ().

`[signal]` void QMessageBox:: buttonClicked ( QAbstractButton * button )

This signal is emitted whenever a button is clicked inside the QMessageBox . The button that was clicked in returned in button .

QMessageBox::ButtonRole QMessageBox:: buttonRole ( QAbstractButton * button ) const

Returns the button role for the specified button 。此函数返回 InvalidRole if button is nullptr or has not been added to the message box.

另请参阅 buttons () 和 addButton ().

QList < QAbstractButton *> QMessageBox:: buttons () const

Returns a list of all the buttons that have been added to the message box.

另请参阅 buttonRole (), addButton ()，和 removeButton ().

`[override virtual protected]` void QMessageBox:: changeEvent ( QEvent * ev )

重实现： QWidget::changeEvent (QEvent *event).

QCheckBox *QMessageBox:: checkBox () const

Returns the checkbox shown on the dialog. This is nullptr if no checkbox is set.

另请参阅 setCheckBox ().

QAbstractButton *QMessageBox:: clickedButton () const

Returns the button that was clicked by the user, or nullptr if the user hit the Esc key and no Esc 按钮 was set.

若 exec () 尚未被调用，返回 nullptr。

范例：

QMessageBox messageBox(this);
QAbstractButton *disconnectButton =
      messageBox.addButton(tr("Disconnect"), QMessageBox::ActionRole);
...
messageBox.exec();
if (messageBox.clickedButton() == disconnectButton) {
    ...
}

另请参阅 standardButton () 和 button ().

`[override virtual protected]` void QMessageBox:: closeEvent ( QCloseEvent * e )

重实现： QDialog::closeEvent (QCloseEvent *e).

`[static]` QMessageBox::StandardButton QMessageBox:: critical ( QWidget * parent , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = Ok, QMessageBox::StandardButton defaultButton = NoButton)

Opens a critical message box with the given title and text in front of the specified parent 小部件。

标准 buttons 被添加到消息框。 defaultButton specifies the button used when Enter is pressed. defaultButton must refer to a button that was given in buttons 。若 defaultButton is QMessageBox::NoButton , QMessageBox chooses a suitable default automatically.

Returns the identity of the standard button that was clicked. If Esc was pressed instead, the Esc 按钮被返回。

消息框是应用程序模态对话框。

警告： 不要删除 parent during the execution of the dialog. If you want to do this, you should create the dialog yourself using one of the QMessageBox 构造函数。

另请参阅 question (), warning ()，和 information ().

QPushButton *QMessageBox:: defaultButton () const

Returns the button that should be the message box's 默认按钮。返回 nullptr 若未设置默认按钮。

另请参阅 setDefaultButton (), addButton ()，和 QPushButton::setDefault ().

QAbstractButton *QMessageBox:: escapeButton () const

返回被激活按钮，当按下 Esc 键时。

默认情况下， QMessageBox attempts to automatically detect an escape button as follows:

If there is only one button, it is made the escape button.
若有 Cancel button, it is made the escape button.
On macOS only, if there is exactly one button with the role QMessageBox::RejectRole , it is made the escape button.

When an escape button could not be automatically detected, pressing Esc 不起作用。

另请参阅 setEscapeButton () 和 addButton ().

`[override virtual protected]` bool QMessageBox:: event ( QEvent * e )

重实现： QWidget::event (QEvent *event).

`[override virtual slot]` int QMessageBox:: exec ()

重实现： QDialog::exec ().

展示消息框作为模态对话框，阻塞直到用户关闭它。

当使用 QMessageBox with standard buttons, this function returns a StandardButton value indicating the standard button that was clicked. When using QMessageBox with custom buttons, this function returns an opaque value; use clickedButton () to determine which button was clicked.

注意： The result () function returns also StandardButton value instead of QDialog::DialogCode .

Users cannot interact with any other window in the same application until they close the dialog, either by clicking a button or by using a mechanism provided by the window system.

另请参阅 show () 和 result ().

`[static]` QMessageBox::StandardButton QMessageBox:: information ( QWidget * parent , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = Ok, QMessageBox::StandardButton defaultButton = NoButton)

打开信息消息框采用给定 title and text in front of the specified parent 小部件。

Returns the identity of the standard button that was clicked. If Esc was pressed instead, the Esc 按钮被返回。

消息框是应用程序模态对话框。

警告： 不要删除 parent during the execution of the dialog. If you want to do this, you should create the dialog yourself using one of the QMessageBox 构造函数。

另请参阅 question (), warning ()，和 critical ().

`[override virtual protected]` void QMessageBox:: keyPressEvent ( QKeyEvent * e )

重实现： QDialog::keyPressEvent (QKeyEvent *e).

void QMessageBox:: open ( QObject * receiver , const char * member )

打开对话框并连接其 finished () 或 buttonClicked () 信号到槽，指定通过 receiver and member 。若槽在 member has a pointer for its first parameter the connection is to buttonClicked (), otherwise the connection is to finished ().

将从槽断开信号连接，当关闭对话框时。

`[static]` QMessageBox::StandardButton QMessageBox:: question ( QWidget * parent , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = StandardButtons(Yes | No), QMessageBox::StandardButton defaultButton = NoButton)

打开问题消息框采用给定 title and text in front of the specified parent 小部件。

Returns the identity of the standard button that was clicked. If Esc was pressed instead, the Esc 按钮被返回。

消息框是应用程序模态对话框。

警告： 不要删除 parent during the execution of the dialog. If you want to do this, you should create the dialog yourself using one of the QMessageBox 构造函数。

另请参阅 information (), warning ()，和 critical ().

void QMessageBox:: removeButton ( QAbstractButton * button )

移除 button 从按钮框但不删除它。

另请参阅 addButton () 和 setStandardButtons ().

`[override virtual protected]` void QMessageBox:: resizeEvent ( QResizeEvent * event )

重实现： QDialog::resizeEvent (QResizeEvent *).

void QMessageBox:: setCheckBox ( QCheckBox * cb )

Sets the checkbox cb on the message dialog. The message box takes ownership of the checkbox. The argument cb 可以是 nullptr to remove an existing checkbox from the message box.

另请参阅 checkBox ().

void QMessageBox:: setDefaultButton ( QPushButton * button )

设置消息框的默认按钮 to button .

另请参阅 defaultButton (), addButton ()，和 QPushButton::setDefault ().

void QMessageBox:: setDefaultButton ( QMessageBox::StandardButton button )

设置消息框的默认按钮 to button .

另请参阅 addButton () 和 QPushButton::setDefault ().

void QMessageBox:: setEscapeButton ( QAbstractButton * button )

Sets the button that gets activated when the Escape key is pressed to button .

另请参阅 escapeButton (), addButton ()，和 clickedButton ().

void QMessageBox:: setEscapeButton ( QMessageBox::StandardButton button )

Sets the buttons that gets activated when the Escape key is pressed to button .

另请参阅 addButton () 和 clickedButton ().

`[since 6.6]` void QMessageBox:: setOption ( QMessageBox::Option option , bool on = true)

设置给定 option 为被启用若 on 为 true；否则，清零给定 option .

选项 (尤其 Option::DontUseNativeDialog option) should be set before showing the dialog.

Setting options while the dialog is visible is not guaranteed to have an immediate effect on the dialog.

设置选项在改变其它特性后，可能导致这些值不起作用。

该函数在 Qt 6.6 引入。

另请参阅 options and testOption ().

void QMessageBox:: setWindowModality ( Qt::WindowModality windowModality )

此函数投影 QWidget::setWindowModality ().

Sets the modality of the message box to windowModality .

On macOS, if the modality is set to Qt::WindowModal and the message box has a parent, then the message box will be a Qt::Sheet ，否则消息框将是标准对话框。

void QMessageBox:: setWindowTitle (const QString & title )

此函数投影 QWidget::setWindowTitle ().

Sets the title of the message box to title . On macOS, the window title is ignored (as required by the macOS Guidelines).

`[override virtual protected]` void QMessageBox:: showEvent ( QShowEvent * e )

重实现： QDialog::showEvent (QShowEvent *event).

QMessageBox::StandardButton QMessageBox:: standardButton ( QAbstractButton * button ) const

返回的标准按钮枚举值对应给定 button ，或 NoButton 若给定 button 不是标准按钮。

另请参阅 button () 和 standardButtons ().

`[since 6.6]` bool QMessageBox:: testOption ( QMessageBox::Option option ) const

返回 true 若给定 option 被启用；否则，返回 false。

该函数在 Qt 6.6 引入。

另请参阅 options and setOption ().

`[static]` QMessageBox::StandardButton QMessageBox:: warning ( QWidget * parent , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = Ok, QMessageBox::StandardButton defaultButton = NoButton)

Opens a warning message box with the given title and text in front of the specified parent 小部件。

Returns the identity of the standard button that was clicked. If Esc was pressed instead, the Esc 按钮被返回。

消息框是应用程序模态对话框。

警告： 不要删除 parent during the execution of the dialog. If you want to do this, you should create the dialog yourself using one of the QMessageBox 构造函数。

另请参阅 question (), information ()，和 critical ().

宏文档编制

QT_REQUIRE_VERSION ( int argc , char ** argv , const char * version )

This macro can be used to ensure that the application is run with a recent enough version of Qt. This is especially useful if your application depends on a specific bug fix introduced in a bug-fix release (for example, 6.1.2).

The argc and argv parameters are the main() function's argc and argv parameters. The version parameter is a string literal that specifies which version of Qt the application requires (for example, "6.1.2").

范例：

#include <QApplication>
#include <QMessageBox>
int main(int argc, char *argv[])
{
    QT_REQUIRE_VERSION(argc, argv, "4.0.2")
    QApplication app(argc, argv);
    ...
    return app.exec();
}

QMessageBox 类

公共类型

特性

公共函数

公共槽

信号

静态公共成员

重实现保护函数

宏

详细描述

基于特性的 API

富文本和文本格式特性

严重级别、图标和像素图特性

静态函数 API

高级用法

默认键和 Esc 键

成员类型文档编制

enum QMessageBox:: ButtonRole

enum QMessageBox:: 图标

[since 6.6] enum class QMessageBox:: Option flags QMessageBox:: Options

enum QMessageBox:: StandardButton flags QMessageBox:: StandardButtons

特性文档编制

detailedText : QString

icon : 图标

iconPixmap : QPixmap

informativeText : QString

[since 6.6] options : Options

standardButtons : StandardButtons

text : QString

textFormat : Qt::TextFormat

textInteractionFlags : Qt::TextInteractionFlags

成员函数文档编制

[explicit] QMessageBox:: QMessageBox ( QWidget * parent = nullptr)

QMessageBox:: QMessageBox ( QMessageBox::Icon icon , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = NoButton, QWidget * parent = nullptr, Qt::WindowFlags f = Qt::Dialog | Qt::MSWindowsFixedSizeDialogHint)

[virtual noexcept] QMessageBox:: ~QMessageBox ()

[static] void QMessageBox:: about ( QWidget * parent , const QString & title , const QString & text )

[static] void QMessageBox:: aboutQt ( QWidget * parent , const QString & title = QString())

void QMessageBox:: addButton ( QAbstractButton * button , QMessageBox::ButtonRole role )

QPushButton *QMessageBox:: addButton (const QString & text , QMessageBox::ButtonRole role )

QPushButton *QMessageBox:: addButton ( QMessageBox::StandardButton button )

QAbstractButton *QMessageBox:: button ( QMessageBox::StandardButton which ) const

[signal] void QMessageBox:: buttonClicked ( QAbstractButton * button )

QMessageBox::ButtonRole QMessageBox:: buttonRole ( QAbstractButton * button ) const

QList < QAbstractButton *> QMessageBox:: buttons () const

[override virtual protected] void QMessageBox:: changeEvent ( QEvent * ev )

QCheckBox *QMessageBox:: checkBox () const

QAbstractButton *QMessageBox:: clickedButton () const

[override virtual protected] void QMessageBox:: closeEvent ( QCloseEvent * e )

[static] QMessageBox::StandardButton QMessageBox:: critical ( QWidget * parent , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = Ok, QMessageBox::StandardButton defaultButton = NoButton)

QPushButton *QMessageBox:: defaultButton () const

QAbstractButton *QMessageBox:: escapeButton () const

[override virtual protected] bool QMessageBox:: event ( QEvent * e )

[override virtual slot] int QMessageBox:: exec ()

[static] QMessageBox::StandardButton QMessageBox:: information ( QWidget * parent , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = Ok, QMessageBox::StandardButton defaultButton = NoButton)

[override virtual protected] void QMessageBox:: keyPressEvent ( QKeyEvent * e )

void QMessageBox:: open ( QObject * receiver , const char * member )

[static] QMessageBox::StandardButton QMessageBox:: question ( QWidget * parent , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = StandardButtons(Yes | No), QMessageBox::StandardButton defaultButton = NoButton)

void QMessageBox:: removeButton ( QAbstractButton * button )

[override virtual protected] void QMessageBox:: resizeEvent ( QResizeEvent * event )

void QMessageBox:: setCheckBox ( QCheckBox * cb )

void QMessageBox:: setDefaultButton ( QPushButton * button )

void QMessageBox:: setDefaultButton ( QMessageBox::StandardButton button )

void QMessageBox:: setEscapeButton ( QAbstractButton * button )

void QMessageBox:: setEscapeButton ( QMessageBox::StandardButton button )

[since 6.6] void QMessageBox:: setOption ( QMessageBox::Option option , bool on = true)

void QMessageBox:: setWindowModality ( Qt::WindowModality windowModality )

void QMessageBox:: setWindowTitle (const QString & title )

[override virtual protected] void QMessageBox:: showEvent ( QShowEvent * e )

QMessageBox::StandardButton QMessageBox:: standardButton ( QAbstractButton * button ) const

[since 6.6] bool QMessageBox:: testOption ( QMessageBox::Option option ) const

[static] QMessageBox::StandardButton QMessageBox:: warning ( QWidget * parent , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = Ok, QMessageBox::StandardButton defaultButton = NoButton)

宏文档编制

QT_REQUIRE_VERSION ( int argc , char ** argv , const char * version )

内容

`[since 6.6]` enum class QMessageBox:: Option
flags QMessageBox:: Options

enum QMessageBox:: StandardButton
flags QMessageBox:: StandardButtons

`[since 6.6]` options : Options

`[explicit]` QMessageBox:: QMessageBox ( QWidget * parent = nullptr)

`[virtual noexcept]` QMessageBox:: ~QMessageBox ()

`[static]` void QMessageBox:: about ( QWidget * parent , const QString & title , const QString & text )

`[static]` void QMessageBox:: aboutQt ( QWidget * parent , const QString & title = QString())

QPushButton QMessageBox:: addButton (const QString & text* , QMessageBox::ButtonRole role )

QPushButton QMessageBox:: addButton ( QMessageBox::StandardButton button* )

QAbstractButton QMessageBox:: button ( QMessageBox::StandardButton which* ) const

`[signal]` void QMessageBox:: buttonClicked ( QAbstractButton * button )

`[override virtual protected]` void QMessageBox:: changeEvent ( QEvent * ev )

`[override virtual protected]` void QMessageBox:: closeEvent ( QCloseEvent * e )

`[static]` QMessageBox::StandardButton QMessageBox:: critical ( QWidget * parent , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = Ok, QMessageBox::StandardButton defaultButton = NoButton)

`[override virtual protected]` bool QMessageBox:: event ( QEvent * e )

`[override virtual slot]` int QMessageBox:: exec ()

`[static]` QMessageBox::StandardButton QMessageBox:: information ( QWidget * parent , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = Ok, QMessageBox::StandardButton defaultButton = NoButton)

`[override virtual protected]` void QMessageBox:: keyPressEvent ( QKeyEvent * e )

`[static]` QMessageBox::StandardButton QMessageBox:: question ( QWidget * parent , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = StandardButtons(Yes | No), QMessageBox::StandardButton defaultButton = NoButton)

`[override virtual protected]` void QMessageBox:: resizeEvent ( QResizeEvent * event )

`[since 6.6]` void QMessageBox:: setOption ( QMessageBox::Option option , bool on = true)

`[override virtual protected]` void QMessageBox:: showEvent ( QShowEvent * e )

`[since 6.6]` bool QMessageBox:: testOption ( QMessageBox::Option option ) const

`[static]` QMessageBox::StandardButton QMessageBox:: warning ( QWidget * parent , const QString & title , const QString & text , QMessageBox::StandardButtons buttons = Ok, QMessageBox::StandardButton defaultButton = NoButton)