• PySide 模块
  • PySide.QtDeclarative
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    QDeclarativeParserStatus

    继承者: QDeclarativeItem

    详细描述

    PySide.QtDeclarative.QDeclarativeParserStatus class provides updates on the QML parser state.

    PySide.QtDeclarative.QDeclarativeParserStatus provides a mechanism for classes instantiated by a PySide.QtDeclarative.QDeclarativeEngine to receive notification at key points in their creation.

    This class is often used for optimization purposes, as it allows you to defer an expensive operation until after all the properties have been set on an object. For example, QML's 文本 element uses the parser status to defer text layout until all of its properties have been set (we don't want to layout when the text is assigned, and then relayout when the font is assigned, and relayout again when the width is assigned, and so on).

    要使用 PySide.QtDeclarative.QDeclarativeParserStatus , you must inherit both a PySide.QtCore.QObject -derived class and PySide.QtDeclarative.QDeclarativeParserStatus , and use the Q_INTERFACES() 宏。

    class MyObject : public QObject, public QDeclarativeParserStatus
    {
        Q_OBJECT
        Q_INTERFACES(QDeclarativeParserStatus)
    public:
        MyObject(QObject *parent = 0);
        ...
        void classBegin();
        void componentComplete();
    }
    									
    class PySide.QtDeclarative. QDeclarativeParserStatus
    PySide.QtDeclarative.QDeclarativeParserStatus. classBegin ( )

    Invoked after class creation, but before any properties have been set.

    PySide.QtDeclarative.QDeclarativeParserStatus. componentComplete ( )

    Invoked after the root component that caused this instantiation has completed construction. At this point all static values and binding values have been assigned to the class.