js method to control image size by dragging slider_javascript skills

The example in this article describes how to use js to drag the slider to control the size of the image. Share it with everyone for your reference. The specific implementation method is as follows:

Copy code The code is as follows:

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<script><br> //golbal<br> var pv = null;<br> var sd = null;<br> window.onload=function(){<br> pv = new PicView("/images/m01.jpg");<br> sd = new Slider(<br> function(p){<br> document.getElementById("sliderBlock").innerHTML = 2*p "%";<br> pv.expand(2*p/100);<br> },function(){});<br> }<br> var PicView = function(url,alt){<br> this.url=url;<br> this.obj=null;<br> this.alt=alt?alt:"";<br> this.realWidth=null;<br> this.realHeight=null;<br> this.zoom=1;<br> this.init();<br> }<br> PicView.prototype.init=function(){<br> var _img=document.createElement("img");<br> _img.src = this.url;<br> _img.alt = this.alt;<br> _img.style.zoom = this.zoom;<br> document.getElementById("picViewPanel").appendChild(_img);<br> this.obj=_img;<br> this.realWidth=_img.offsetWidth;<br> this.realHeight=_img.offsetHeight;<br> }<br> PicView.prototype.reBind=function(){<br> this.obj.style.width = this.realWidth*this.zoom "px";<br> this.obj.style.height = this.realHeight*this.zoom "px";<br> //this.obj.style.zoom = this.zoom;<br> }<br> PicView.prototype.expand=function(n){<br> this.zoom=n;<br> this.reBind();<br> }<br> var Slider = function(ing,ed){<br> this.block=document.getElementById("sliderBlock");<br> this.percent = 0;<br> this.value = 0;<br> this.ing = ing;<br> this.ed = ed;<br> this.init();<br> }<br> Slider.prototype.init=function(){<br> var _sx=0;<br> var _cx=0;<br> var o=this.block;<br> var me=this;<br> o.onmousedown=function(e){<br> var e=window.event||e;<br> _sx = o.offsetLeft;<br> _cx = e.clientX-_sx;<br> document.body.onmousemove=move;<br> document.body.onmouseup=up;<br> };<br> function move(e){<br> var e=window.event||e;<br> var pos_x = e.clientX - _cx;<br> pos_x=pos_x<13?13:pos_x;<br /> pos_x=pos_x>248 15-50?248 15-50:pos_x;<br> o.style.left = pos_x "px";<br> me.percent=(pos_x-13)/2;<br> me.ing(me.percent);<br> }<br> function up(){<br> document.body.onmousemove=function(){};<br> document.body.onmouseup=function(){};<br> }<br> }<br> </script>

I hope this article will be helpful to everyone’s JavaScript programming design.