动态创建对象。 更多...
| import 语句： | import QtQml.Models 2.2 |
A Instantiator can be used to control the dynamic creation of objects, or to dynamically create multiple objects from a template.
The Instantiator element will manage the objects it creates. Those objects are parented to the Instantiator and can also be deleted by the Instantiator if the Instantiator's properties change. Objects can also be destroyed dynamically through other means, and the Instantiator will not recreate them unless the properties of the Instantiator change.
注意： Instantiator is part of QtQml .Models since version 2.14 and part of QtQml since version 2.1. Importing Instantiator via QtQml is deprecated since Qt 5.14.
| active : bool |
When active is true, and the delegate component is ready, the Instantiator will create objects according to the model. When active is false, no objects will be created and any previously created objects will be destroyed.
默认为 true。
| asynchronous : bool |
When asynchronous is true the Instantiator will attempt to create objects asynchronously. This means that objects may not be available immediately, even if active is set to true.
可以使用 objectAdded signal to respond to items being created.
Default is false.
| count : int |
The number of objects the Instantiator is currently managing.
| [default] delegate : QtQml::Component |
The component used to create all objects.
Note that an extra variable, index, will be available inside instances of the delegate. This variable refers to the index of the instance inside the Instantiator, and can be used to obtain the object through the objectAt method of the Instantiator.
If this property is changed, all instances using the old delegate will be destroyed and new instances will be created using the new delegate.
| model : variant |
This property can be set to any of the supported data models :
The type of model affects the properties that are exposed to the delegate .
Default value is 1, which creates a single delegate instance.
另请参阅 数据模型 .
| 对象 : QtObject |
This is a reference to the first created object, intended as a convenience for the case where only one object has been created.
| objectAdded ( int index , QtObject object ) |
This signal is emitted when an object is added to the Instantiator. The index parameter holds the index which the object has been given, and the object parameter holds the QtObject that has been added.
注意：
相应处理程序是
onObjectAdded
.
| objectRemoved ( int index , QtObject object ) |
This signal is emitted when an object is removed from the Instantiator. The index parameter holds the index which the object had been given, and the object parameter holds the QtObject that has been removed.
Do not keep a reference to object if it was created by this Instantiator, as in these cases it will be deleted shortly after the signal is handled.
注意：
相应处理程序是
onObjectRemoved
.
| QtObject objectAt ( int index ) |
Returns a reference to the object with the given index .
