QML按键事件处理

QML提供了对应的按键处理方法，我们接下来实现一个通过键盘上的方向键来移动文本，代码如下：

 import QtQuick 2.4
 import QtQuick.Controls 1.3
 import QtQuick.Window 2.2
 import QtQuick.Dialogs 1.2

 Rectangle{
     id: root
     width:  512
     height: 512
     color: "gray"

     focus: true
     Keys.enabled: true
     Keys.onEscapePressed: Qt.quit();
     Keys.forwardTo: [moveText, likeQt];

     Text {
         id: moveText
         x: 20; y: 20;
         width: 200; height: 30;

         text: "Moving Text"
         color: "blue"
         font {bold: true; pixelSize: 30}

         Keys.enabled: true
         Keys.onPressed: {
             switch (event.key){
             case Qt.Key_Left:
                 x -= 10;
                 break;
             case Qt.Key_Right:
                 x += 10;
                 break;
             case Qt.Key_Up:
                 y -= 10;
                 break;
             case Qt.Key_Down:
                 y += 10;
                 break;
             default:
                 return;
             }
             event.accepted = true;
         }
     }

     CheckBox {
         id: likeQt
         text: "Like Qt Quick"
         z:1

         anchors.left: parent.left
         anchors.leftMargin: 10
         anchors.bottom: parent.bottom
         anchors.bottomMargin: 10
     }
 }