js实现图片滚轮、按钮缩放大小,图片旋转,图片拖拽

JavaScript08

js实现图片滚轮、按钮缩放大小,图片旋转,图片拖拽,第1张

<div class="upload-img-box" ref="moveWrap">

<div class="show-box" ref="rotate" @mousedown="moveImg" @mousewheel.prevent="rollImg($event,)">

<img :src="singleList.fileImgUrl" class="uploadimg" ref="img" :style="{transform:'scale('+multiples/100+') rotate('+rotate +'deg)'}"/>

</div>

<div class="img-plus" @click="toBIgChange()"><span class="tip">放大</span></div>

<div class="img-minus" @click="toSmallChange()"><span class="tip">缩小</span></div>

<div class="img-rotate" @click="toRotate()"><span class="tip">旋转</span></div>

</div>

讲一下大致思路吧,希望能帮到你

通常来说,元素id要求是唯一的,虽然不唯一也不会报错,但可能导致代码得不到你想要的效果。你在for循环里面定义了 id="blue2" 这是不合理的。

你不能在每个元素上统一设置 transform, 因为这样的话一变全都变了,区分不了。

for循环你能拿到索引 index,你可以根据index拿到当前展示的元素,那么 通过 index+1就能拿到下一个元素。注意,需要判断是否存在下一个元素

针对当前元素做缩小处理,下一个元素做放大处理。el.style.transform = 'scale()'

小程序的开发和原生js多多少少还是有些区别的,具体的情况需要你自己调试了。

以下内容需要一定的ExtJs以及Js知识基础

Ext.define('window.ViewPicWin',{//定义一个类继承window 所有配置都在该类里 包括图片地址等

    extend : 'Ext.window.Window',

    title : '大图查看',

    bodyStyle: {

            background: 'url(背景图片地址) repeat'//此处给窗口加个背景图

        },

    bodyPadding : '1 1 1 1',

    autoShow : true,

    modal : true,

    alwaysOnTop : true,

    scrollable : true,

    width : 900,

    height : 500,

    config : {

        src : null, //需要展示的图片地址

        clickX: null,//存放鼠标按下时指针X的位置

            clickY: null,//存放鼠标按下时指针Y的位置

            isMoving: false,//一个标识 作为判断当前鼠标是否按下状态 即图片拖拽中状态

            offset : 1.2 //放大倍数 默认1.2倍 与原图放大缩小

    },

    initComponent : function(){

        var me = this

        var minWidth = me.width-9 //用作图片在window里的最小宽

        var minHeight = me.height-54 //用作图片在window里的最小高(window的head大概54px)

        Ext.applyIf(me,{

            items : [{

                xtype : 'image',

                width : minWidth,

                height : minHeight,

                src : me.getSrc(),

                listeners : {

                    afterrender: {

                        fn : me.onAfterRender,//监听图片渲染完成事件

                        scope : me

                    }

                }

            }]

        })

        me.callParent(arguments)

    },

    onAfterRender : function(img, eOpts){

        var win = img.up('window')

        var minPicWidth = img.getWidth()

        var minPicHeight = img.getHeight()

        Ext.get(img.getId()).on({  //获得Ext.dom.Element 添加事件 这个区别于原生的element元素 这里是ExtJs自己包装的element元素

            'mousewheel': {   //监听鼠标滚轮事件(火狐浏览器叫DOMMouseScroll),extjs增加监听事件前面没有on区别于普通js,他是on('事件名':{...})

                fn : function(e){

                    e.preventDefault()

                    var type = e.getWheelDelta()

                    win.zoom(Ext.get(img.getId()),win.getOffset(),type>0?true:false,minPicWidth,minPicHeight,win,e.getX(),e.getY())

                }

            },

            'mousedown': {

                fn: function(e){

                    document.getElementById(img.getId()).style.cursor = "move"

                    e.stopEvent()

                        win.setClickX(e.getX())

                        win.setClickY(e.getY())

                        win.setIsMoving(true)

                }

            },

            'mouseup': {

                fn: function(e){

                    if(win.getIsMoving()){

                        win.setClickX(null)

                            win.setClickY(null)

                            win.setIsMoving(false)

                    }

                }

            },

            'mousemove': {

                fn: function(e){

                    if(win.getIsMoving()){

                        var left = e.getX()-win.getClickX()//x偏移量

                        var top = e.getY()-win.getClickY()//y偏移量

                        if( img.getX()>(win.getX()+50)

                            ||img.getY()>(win.getY()+100)){

                            document.getElementById(img.getId()).style.cursor = "not-allowed"

                            win.setIsMoving(false)

                            var task = new Ext.util.DelayedTask(function(){

                                win.setScrollX(0,false)

                                win.setScrollY(0,false)

                                img.setX(win.getX()-5)

                                img.setY(win.getY()+45)

                                document.getElementById(img.getId()).style.cursor = "move"

                            })

                            task.delay(1000)

                        }else if((img.getX()+img.getWidth())<(win.getX()+win.getWidth()-50)

                                ||img.getY()+img.getHeight()<win.getY()+win.getHeight()-100){

                            document.getElementById(img.getId()).style.cursor = "not-allowed"

                            win.setIsMoving(false)

                            var task = new Ext.util.DelayedTask(function(){

                                win.setScrollX(img.getWidth(),false)

                                win.setScrollY(img.getHeight(),false)

                                    img.setX(win.getX()-(img.getWidth()-win.getWidth()))

                                    img.setY(win.getY()-(img.getHeight()-win.getHeight()))

                                    document.getElementById(img.getId()).style.cursor = "move"

                            })

                            task.delay(1000)

                        }else {

                            img.setX(win.getLastMarginX()+left)

                            img.setY(win.getLastMarginY()+top)

                        }

                    }

                }

            }

        })

    },

    /*

     * 图片放大缩小

     * el:图片dom对象

     * offset:放大缩小的倍数

     * type: true/false 放大缩小的标识

     * mw: 最小宽度

     * mh: 最小高度

     * win: 图片外面的window(标定scroll用) x:鼠标x坐标 y:鼠标y坐标

     */

    zoom : function(el, offset, type, mw, mh, win, x, y) {  

        var width = el.getWidth()  

        var height = el.getHeight()  

        var nwidth = type ? (width * offset) : (width / offset)  

        var nheight = type ? (height * offset) : (height / offset) 

        el.setWidth(nwidth<=mw ? mw : nwidth)

        el.setHeight(nheight<=mh ? mh : nheight)

        //修正参数

        var elX = el.getX(),

            elY = el.getY(),

            elW = el.getWidth(),

            elH = el.getHeight(),

            winX = win.getX(),

            winY = win.getY(),

            winW = win.getWidth(),

            winH = win.getHeight()

        if(elX>=winX+50 || elY>winY+100){ //左上角距离偏大

            el.setX(winX)

            el.setY(winY+45)

        }else if(elX+elW<winX+winW-50 || elY+elH<winY+winH-100){ //右下角距离偏大

            el.setX(winX-(elW-winW))

            el.setY(winY-(elH-winH))

        }else { //正常

            var left = (x-el.getX())*(offset-1)  //当前鼠标位置x偏移量

            var top = (y-el.getY())*(offset-1)  //当前鼠标位置y偏移量

            if(type){

                        win.setScrollX(win.getScrollX()+left,false)

                win.setScrollY(win.getScrollY()+top,false)

                }else{

                        win.setScrollX(win.getScrollX()-left/offset<=0?0:win.getScrollX()-left/offset,false)

                    win.setScrollY(win.getScrollY()-top/offset<=0?0:win.getScrollY()-top/offset,false)

                }

            }

    }

})