QMl中实现通过鼠标滚轮放大、缩小图片

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/MyLovelyJay/article/details/81668381

import QtQuick 2.7
import QtQuick.Controls 2.0
import QtQuick.Layouts 1.0
import QtQuick.Controls 1.4
import QtQuick.Controls.Styles 1.2
import QtQuick.Dialogs 1.2
import QtQuick.Controls.Styles 1.3


ApplicationWindow{
        title:qsTr("Hello Image");
        width:600; height:600;
        visible: true
        Rectangle{
             id:imageDisplay;
             width:600; height:600;
             Image{
                 id:img;
                 width:parent.width;
                 height:parent.height;
                 anchors.centerIn: parent;
                 fillMode: Image.PreserveAspectFit;
                 source:"city.jpg";
             }
             MouseArea{
                    anchors.fill: parent
                    onWheel: {
                        if (wheel.modifiers & Qt.ControlModifier) {
                            imageDisplay.rotation += wheel.angleDelta.y / 120 * 5;
                            if (Math.abs(imageDisplay.rotation) < 4)
                                imageDisplay.rotation = 0;
                        } else {
                            imageDisplay.rotation += wheel.angleDelta.x / 120;
                            if (Math.abs(imageDisplay.rotation) < 0.6)
                                imageDisplay.rotation = 0;
                            var scaleBefore = imageDisplay.scale;
                            imageDisplay.scale += imageDisplay.scale * wheel.angleDelta.y / 120 / 10;
                        }
                    }
             }
        }
}