Dynamically creates nodes. 更多...
import 语句: | import Qt3D.Core 2.15 |
Since: | Qt 5.5 |
A NodeInstantiator can be used to control the dynamic creation of nodes, or to dynamically create multiple objects from a template.
The NodeInstantiator element will manage the objects it creates. Those objects are parented to the Instantiator and can also be deleted by the NodeInstantiator if the NodeInstantiator's properties change. Nodes can also be destroyed dynamically through other means, and the NodeInstantiator will not recreate them unless the properties of the NodeInstantiator change.
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.
默认为
false
.
[read-only] 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 itemAt 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 .
[read-only] 对象 : QtQml::QtObject |
This is a reference to the first created object, intended as a convenience for the case where only one object has been created.
This signal is emitted when a node is added to the NodeInstantiator 。 index parameter holds the index which the node has been given, and the object parameter holds the Node that has been added.
相应处理程序是
onNodeAdded
.
注意:
相应处理程序是
onObjectAdded
.
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.
相应处理程序是
onObjectRemoved
.
注意:
相应处理程序是
onObjectRemoved
.
QtQml::QtObject objectAt ( int index ) |
Returns a reference to the object with the given index .