封装 QML 组件定义。 更多...
导入语句: | import QtQuick . |
Components are reusable, encapsulated QML types with well-defined interfaces.
Components are often defined by component files - that is,
.qml
files. The
组件
type allows QML components to be defined inline, within a QML document, rather than as a separate QML file.
组件
type is commonly used to provide graphical components for views. For example, the
ListView::delegate
and
Repeater::delegate
properties require a
组件
to specify how each list item is to be displayed.
import QtQuick 2.15 Item { Component { id: redSquare Rectangle { color: "red" width: 10 height: 10 } } Row { Repeater { model: 3 delegate: redSquare } } }
Defining a
组件
is similar to defining a QML document. A QML document contains a single top-level item that defines the behavior and properties of the component. It cannot define properties or behavior outside of that top-level item. In the same way, a
组件
definition contains a single top-level item (which in the above example is a
Rectangle
) and cannot define any data outside of this item, with the exception of an
id
.
另请参阅 Model-View-Delegate pattern .
Emitted after the object has been instantiated. This can be used to execute script code at startup, after the QML environment is ready.
相应处理程序是
onCompleted
. It can be declared on any object. The order of running the
onCompleted
handlers is undefined.
Rectangle { Component.onCompleted: console.log("Completed Running!") Rectangle { Component.onCompleted: console.log("Nested Completed Running!") } }
注意:
相应处理程序是
onCompleted
.