JavaScript实现图片上传预览

上传图片时实现图片预览

<input id="fileData" name="checkPizhu" type="hidden">
<input id="file" type="file" class="text" style="height: 20px;line-height: 20px;" onchange="javascript:setImagePreviews();" />

<div id="preview" style="width:100%;margin-top:5px;margin-bottom:5px;"></div>

//图片上传预览功能function setImagePreviews(avalue) {var docObj = document.getElementById("file");var dd = document.getElementById("preview");dd.innerHTML = "";var fileList = docObj.files;for (var i = 0; i < fileList.length; i++) {dd.innerHTML += "<div align='center'> <img id='img" + i + "' /> </div>";var imgObjPreview = document.getElementById("img"+i);if (docObj.files && docObj.files[i]) {//火狐下，直接设img属性imgObjPreview.style.display = 'block';//imgObjPreview.style.width = '250px';//设置图片显示尺寸//imgObjPreview.style.height = '280px';//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[i]);}else {//IE下，使用滤镜docObj.select();var imgSrc = document.selection.createRange().text;alert(imgSrc)var localImagId = document.getElementById("img" + i);//设置初始大小//localImagId.style.width = "250px";//localImagId.style.height = "280px";//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;}实现效果：