jsp上传图片即时显示效果代码

　2012-12-21 20:15:13　来源：WEB开发网　　　

核心提示：<script>function setImagePreview() { var docObj=document.getElementById("doc"); var imgObjPreview=document.getElementById("p

<script>
function setImagePreview() {        
	var docObj=document.getElementById("doc");         
	var imgObjPreview=document.getElementById("preview");
	if(docObj.files && docObj.files[0]){                        
		//火狐下，直接设img属性                        
		imgObjPreview.style.display = 'block';                        
		imgObjPreview.style.width = '300px';                        
		imgObjPreview.style.height = '120px';                                            
		//imgObjPreview.src = docObj.files[0].getAsDataURL();
		//火狐7以上版本不能用上面的getAsDataURL()方式获取，需要一下方式        
		imgObjPreview.src = window.URL.createObjectURL(docObj.files[0]);
	 }else{                        
		 //IE下，使用滤镜                        
		 docObj.select();                        
		 var imgSrc = document.selection.createRange().text;                        
		 var localImagId = document.getElementById("localImag");
		 //必须设置初始大小                        
		 localImagId.style.width = "250px";                        
		 localImagId.style.height = "200px";
		//图片异常的捕捉，防止用户修改后缀来伪造图片
		try{                                
			localImagId.style.filter="progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale)";                                
			localImagId.filters.item("DXImageTransform.Microsoft.AlphaImageLoader").src = imgSrc;                        
		}catch(e){                                
			alert("您上传的图片格式不正确，请重新选择!");                                
			return false;                        
		}
			imgObjPreview.style.display = 'none';                        
			document.selection.empty();                
		}                
			return true;        
		}
</script>
<body>
<input type=file name="doc" id="doc" onchange="javascript:setImagePreview();">
<p><div id="localImag"><img id="preview" width=-1 height=-1 style="diplay:none" /></div></p>