用onchange绑定了一个事件，然而每次刷新页面会自动触发这个事件，alert了事件源获得了window对象
求解~~~~
代码如下
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>图片上传预览 ie6,7,8, firefox</title>
</head>
<body>
<input type="file" multiple="true" id="picPath" name="imgPath" />
<div id="Preview">
<img id="Preview" />
<img id="Preview2" />
</div>
</body>
<script src="imageUpload.js"></script>
<script>
document.getElementById("picPath").onchange = PreviewImage({
PreviewElementId : "Preview",
fileInput : this,
width : "120px",
height : "120px"
});
</script>
</html>
下面是JS方法（未完成的方法）
/*图片格式验证*/
function checkPic() {
var picPath = document.getElementById("picPath").value;
var type = picPath.substring(picPath.lastIndexOf(".") + 1, picPath.length).toLowerCase();
if (type != "jpg" && type != "bmp" && type != "gif" && type != "png") {
alert("请上传正确的图片格式");
return false;
}
return true;
}
//图片预览
function PreviewImage(jsonObj) {
var upload = jsonObj.fileInput;
var PreviewElementId = jsonObj.PreviewElementId;
alert(upload);
var width = jsonObj.width;
var height = jsonObj.height;
if (checkPic()) {
var imgPath; //图片路径
var imgPath2;
var Browser_Agent = navigator.userAgent;
//判断浏览器的类型
if (Browser_Agent.indexOf("Firefox") != -1) {
//火狐浏览器
imgPath = window.URL.createObjectURL(upload.files[0]); /*需要添加是否双图判断*/
imgPath2 = window.URL.createObjectURL(upload.files[1]);
document.getElementById(divImage).innerHTML = "<img id='imgPreview' src='" + imgPath + "' width='" + width + "' height='" + height + "'/>";
document.getElementById(divImage2).innerHTML = "<img id='imgPreview' src='" + imgPath2 + "' width='" + width + "' height='" + height + "'/>";
} else {
/*多地址解析*/
var valuesArray = upload.value.split(",");
var imgSrc1 = valuesArray[0];
var imgSrc2 = valuesArray[1];
/*容器设置*/
var localImagId1 = document.getElementById(divImage);
var localImagId2 = document.getElementById(divImage2);
//必须设置初始大小
//图片异常的捕捉，防止用户修改后缀来伪造图片
//filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src=' http://')
try {
localImagId1.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader((enabled='true' ,src='" + imgSrc1 + "');";
alert(localImagId1.style.filter);
/*localImagId1.filters.item("DXImageTransform.Microsoft.AlphaImageLoader").src = imgSrc1;
localImagId2.filters.item("DXImageTransform.Microsoft.AlphaImageLoader").src = imgSrc2;*/
} catch (e) {
alert(e);
return false;
}
/* imgObjPreview1.style.display = 'none';
imgObjPreview2.style.display = 'none';*/
/*document.selection.empty();*/
}
}
}
