如何为动态创建的QML元素添加事件处理程序？

Question

根据这篇博文,我动态地为我的gui添加了一些qml组件.如何为新创建的组件添加事件处理程序？

Answer 1

我将用一个例子来解释.1)创建自定义按钮组件,如下所示

//Button.qml ... This component's objects will be dynamically
// created
import QtQuick 2.1

Rectangle {
    width: 100
    height: 50
    color:"blue"
    //Since the buttons are created on the fly,
    //we need to identify the button on which the user
    // has clicked. The id must be unique
    property string buttonId;
    signal clicked(string buttonId);

    MouseArea {
        anchors.fill: parent
        onClicked:parent.clicked(parent.buttonId)
    }
}

这是一个简单的按钮,点击它时会发出点击信号.现在我们可以动态创建一些按钮.

//Main.qml ... creates some buttons on the fly
import QtQuick 2.1
Rectangle{
    id:root
    width:500
    height:500

    function buttonClicked(buttonId)
    {
        console.debug(buttonId);
    }

    function createSomeButtons()
    {
        //Function creates 4 buttons
        var component = Qt.createComponent("Button.qml");
        for(var i=0;i<4;i++)
        {
            var buttonY = i*55; //Button height : 50 + 5 unit margin
            var button = component.createObject(root,{"x":0,"y":buttonY,"buttonId":i+1});

            //Connect the clicked signal of the newly created button
            //to the event handler buttonClicked.
            button.clicked.connect(buttonClicked)
        }
    }
    Component.onCompleted: {
        createSomeButtons();
    }
}

完成Main.qml组件创建后,将创建按钮.创建了4个按钮,在创建每个按钮后,javascript函数buttonClicked作为事件处理程序连接到' Button.qml '的单击信号.每当用户点击按钮时,将使用buttonId作为参数调用buttonClicked函数.从这里开始,您可以在事件处理程序中执行任何操作.