QAbstractFormBuilder Class

The QAbstractFormBuilder class provides a default implementation for classes that create user interfaces at run-time. 更多...

头：	#include <QAbstractFormBuilder>
CMake:	find_package(Qt6 REQUIRED COMPONENTS Designer) target_link_libraries(mytarget PRIVATE Qt6::Designer)
qmake:	QT += designer
继承者：	QFormBuilder

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公共函数

	QAbstractFormBuilder ()
virtual	~QAbstractFormBuilder ()
QString	errorString () const
virtual QWidget *	load (QIODevice * device , QWidget * parent = nullptr)
virtual void	save (QIODevice * device , QWidget * widget )
void	setWorkingDirectory (const QDir & directory )
QDir	workingDirectory () const

详细描述

QAbstractFormBuilder provides a standard interface and a default implementation for constructing forms from user interface files. It is not intended to be instantiated directly. Use the QFormBuilder class to create user interfaces from UI files at run-time. For example:

        MyForm::MyForm(QWidget *parent)
            : QWidget(parent)
        {
            QFormBuilder builder;
            QFile file(":/forms/myWidget.ui");
            file.open(QFile::ReadOnly);
            QWidget *myWidget = builder.load(&file, this);
            file.close();
            auto *layout = new QVBoxLayout(this);
            layout->addWidget(myWidget);
        }

To override certain aspects of the form builder's behavior, subclass QAbstractFormBuilder and reimplement the relevant virtual functions:

load () handles reading of UI format files from arbitrary QIODevices, and construction of widgets from the XML data that they contain.
save () handles saving of widget details in UI format to arbitrary QIODevices.
workingDirectory () 和 setWorkingDirectory () control the directory in which forms are held. The form builder looks for other resources on paths relative to this directory.

The QFormBuilder class is typically used by custom components and applications that embed Qt Designer . Standalone applications that need to dynamically generate user interfaces at run-time use the QUiLoader , found in the Qt UI Tools 模块。

另请参阅 Qt UI Tools .

成员函数文档编制

QAbstractFormBuilder:: QAbstractFormBuilder ()

Constructs a new form builder.

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

Destroys the form builder.

QString QAbstractFormBuilder:: errorString () const

Returns a human-readable description of the last error occurred in load ().

另请参阅 load ().

`[虚拟]` QWidget QAbstractFormBuilder:: load ( QIODevice device , QWidget * parent = nullptr)

Loads an XML representation of a widget from the given device , and constructs a new widget with the specified parent .

另请参阅 save () 和 errorString ().

`[虚拟]` void QAbstractFormBuilder:: save ( QIODevice * device , QWidget * widget )

Saves an XML representation of the given widget 到指定 device in the standard UI file format.

注意： Unlike when saving a form in Qt Designer , all property values are written. This is because, the state of whether a property value was modified or not isn't stored in the Qt property system. The widget that is being saved, could have been created dynamically, not loaded via load (), so in this case the form builder isn't aware of the list of changed properties. Also, there's no generic way to do this for widgets that were created dynamically.

Therefore, you should remove properties that are not required from your resulting XML files, before loading them. Alternatively, if you already know which properties you want to save when you call this method, you can overload computeProperties() and return a filtered list of required properties. Otherwise, unexpected behavior may occur as some of these properties may depend on each other.

另请参阅 load ().

void QAbstractFormBuilder:: setWorkingDirectory (const QDir & directory )

Sets the current working directory of the form builder to the specified directory .

另请参阅 workingDirectory ().

QDir QAbstractFormBuilder:: workingDirectory () const

Returns the current working directory of the form builder.

另请参阅 setWorkingDirectory ().