內容

• 特性
• 詳細描述

Binding QML Element

The Binding element allows arbitrary property bindings to be created. 更多...

Since:

Qt 4.7

• 所有成員列錶，包括繼承成員

特性

• property : string
• target : Object
• value : any
• when : bool

詳細描述

Sometimes it is necessary to bind to a property of an object that wasn't directly instantiated by QML - generally a property of a class exported to QML by C++. In these cases, regular property binding doesn't work. Binding allows you to bind any value to any property.

For example, imagine a C++ application that maps an "app.enteredText" property into QML. You could use Binding to update the enteredText property like this.

TextEdit { id: myTextField; text: "Please type here..." }
Binding { target: app; property: "enteredText"; value: myTextField.text }
					

Whenever the text in the TextEdit is updated, the C++ property will be updated also.

If the binding target or binding property is changed, the bound value is immediately pushed onto the new target.

另請參閱 QtDeclarative .

特性文檔編製

property : string

要更新的特性。

target : 對象

要更新的對象。

value : any

The value to be set on the target object and property. This can be a constant (which isn't very useful), or a bound expression.

當 : bool

This property holds when the binding is active. This should be set to an expression that evaluates to true when you want the binding to be active.

Binding {
    target: contactName; property: 'text'
    value: name; when: list.ListView.isCurrentItem
}