js实现图片放大和拖拽特效代码分享

本文实例讲述了js实现图片放大和拖拽特效代码。分享给大家供大家参考。具体如下：
js实现图片放大和拖拽特效是一款非常实用的js特效，实现了图片的放大和拖拽功能，没用用到jquery插件，是用原生javascript实现的，除了点击放大和缩小按钮来控制图片的放大缩小，还可以使用鼠标的滚轮控制图片的缩放。
运行效果图：                               ----------------------查看效果 源码下载-----------------------

小提示：浏览器中如果不能正常运行，可以尝试切换浏览模式。
 为大家分享的js实现图片放大和拖拽特效代码如下

 
 
 
 
 
 
  body{font-size: 12px;font-family: "Verdana" , "Arial" , "Helvetica" , "sans-serif";} td{font-size: 12px; line-height: 150%;} TD{font-size: 12px; color: #000000;} A{font-size: 12px; color: #000000;} #Layer1{z-index: 100; position: absolute; top: 150px;} #Layer2{z-index: 1; position: absolute;}
 
 


 
 
  
 
 

  

 
 
  
 
 
  
 

核心代码如下：

function onWheelZoom(obj){ //滚轮缩放
 zoom = parseFloat(obj.style.zoom);
 tZoom = zoom + (event.wheelDelta>0 ? 0.05 : -0.05);
 if(tZoom<0.1 ) return true;
 obj.style.zoom=tZoom;
 return false;
}

js关键代码：

drag = 0
move = 0

var ie=document.all;
var nn6=document.getElementById&&!document.all;
var isdrag=false;
var y,x;
var oDragObj;

function moveMouse(e) {
 if (isdrag) {
 oDragObj.style.top = (nn6 ? nTY + e.clientY - y : nTY + event.clientY - y)+"px";
 oDragObj.style.left = (nn6 ? nTX + e.clientX - x : nTX + event.clientX - x)+"px";
 return false;
 }
}

function initDrag(e) {
 var oDragHandle = nn6 ? e.target : event.srcElement;
 var topElement = "HTML";
 while (oDragHandle.tagName != topElement && oDragHandle.className != "dragAble") {
 oDragHandle = nn6 ? oDragHandle.parentNode : oDragHandle.parentElement;
 }
 if (oDragHandle.className=="dragAble") {
 isdrag = true;
 oDragObj = oDragHandle;
 nTY = parseInt(oDragObj.style.top+0);
 y = nn6 ? e.clientY : event.clientY;
 nTX = parseInt(oDragObj.style.left+0);
 x = nn6 ? e.clientX : event.clientX;
 document.onmousemove=moveMouse;
 return false;
 }
}
document.onmousedown=initDrag;
document.onmouseup=new Function("isdrag=false");

function clickMove(s){
 if(s=="up"){
 dragObj.style.top = parseInt(dragObj.style.top) + 100;
 }else if(s=="down"){
 dragObj.style.top = parseInt(dragObj.style.top) - 100;
 }else if(s=="left"){
 dragObj.style.left = parseInt(dragObj.style.left) + 100;
 }else if(s=="right"){
 dragObj.style.left = parseInt(dragObj.style.left) - 100;
 }

}

function smallit(){   
 var height1=images1.height;   
 var width1=images1.width;   
 images1.height=height1/1.2;   
 images1.width=width1/1.2;   
}    
 
function bigit(){   
 var height1=images1.height;   
 var width1=images1.width;   
 images1.height=height1*1.2;   
 images1.width=width1*1.2;   
}    
function realsize()
{
 images1.height=images2.height;  
 images1.width=images2.width;
 block1.style.left = 0;
 block1.style.top = 0;
 
}
function featsize()
{
 var width1=images2.width;   
 var height1=images2.height;   
 var width2=701;   
 var height2=576;   
 var h=height1/height2;
 var w=width1/width2;
 if(height1w)
 {
 images1.height=height2;   
 images1.width=width1*height2/height1;   
 }
 else
 {
 images1.width=width2;   
 images1.height=height1*width2/width1;   
 }
 }
 block1.style.left = 0;
 block1.style.top = 0;
}

function onWheelZoom(obj){ //滚轮缩放
zoom = parseFloat(obj.style.zoom);
tZoom = zoom + (event.wheelDelta>0 ? 0.05 : -0.05);
if(tZoom<0.1 ) return true;
obj.style.zoom=tZoom;
return false;
}

以上就是为大家分享的js实现图片放大和拖拽特效代码，希望大家可以喜欢。