小小的几十行代码，很牛逼，很实用。
支持多个图片的预览，只要new多个对象就行了。
html如下
<!-- zhouxiang www.zhou-xiang.com -->
<!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>
<title>uploadPreview演示</title>
<script src="uploadPreview.js" type="text/javascript"></script>
<script>
window.onload = function () {
new uploadPreview({ UpBtn: "up_img", DivShow: "imgdiv", ImgShow: "imgShow" });
new uploadPreview({ UpBtn: "up_img2", DivShow: "imgdiv2", ImgShow: "imgShow2" });
}
</script>
</head>
<body>
<div id="imgdiv"><img id="imgShow" width="200"/></div>
<input type="file" id="up_img" />
<div id="imgdiv"><img id="imgShow2" width="200" /></div>
<input type="file" id="up_img2" />
</body>
</html>
插件代码如下
/*
*发布时间:2014年12月12日
*插件介绍:图片上传本地预览插件 兼容浏览器(IE 谷歌 火狐) 不支持safari 当然如果是使用这些内核的浏览器基本都兼容
*使用方法:
*界面构造(IMG标签外必须拥有DIV 而且必须给予DIV控件ID)
* <div id="imgdiv"><img id="imgShow" width="120" height="120" /></div>
* <input type="file" id="up_img" />
*调用代码:
* new uploadPreview({ UpBtn: "up_img", DivShow: "imgdiv", ImgShow: "imgShow" });
*参数说明:
*UpBtn:选择文件控件ID;
*DivShow:DIV控件ID;
*ImgShow:图片控件ID;
*Width:预览宽度;
*Height:预览高度;
*ImgType:支持文件类型 格式:["jpg","png"];
*callback:选择文件后回调方法;
*版本:v1.4
更新内容如下:
1.修复回调.
*版本:v1.3
更新内容如下:
1.修复多层级框架获取路径BUG.
2.去除对jquery插件的依赖.
*/
/*
*work:图片预览插件
*/
var uploadPreview = function(setting) {
/*
*work:this(当前对象)
*/
var _self = this;
/*
*work:判断为null或者空值
*/
_self.IsNull = function(value) {
if (typeof (value) == "function") { return false; }
if (value == undefined || value == null || value == "" || value.length == 0) {
return true;
}
return false;
}
/*
*work:默认配置
*/
_self.DefautlSetting = {
UpBtn: "",
DivShow: "",
ImgShow: "",
Width: 100,
Height: 100,
ImgType: ["gif", "jpeg", "jpg", "bmp", "png"],
ErrMsg: "选择文件错误,图片类型必须是(gif,jpeg,jpg,bmp,png)中的一种",
callback: function() { }
};
/*
*work:读取配置
*/
_self.Setting = {
UpBtn: _self.IsNull(setting.UpBtn) ? _self.DefautlSetting.UpBtn : setting.UpBtn,
DivShow: _self.IsNull(setting.DivShow) ? _self.DefautlSetting.DivShow : setting.DivShow,
ImgShow: _self.IsNull(setting.ImgShow) ? _self.DefautlSetting.ImgShow : setting.ImgShow,
Width: _self.IsNull(setting.Width) ? _self.DefautlSetting.Width : setting.Width,
Height: _self.IsNull(setting.Height) ? _self.DefautlSetting.Height : setting.Height,
ImgType: _self.IsNull(setting.ImgType) ? _self.DefautlSetting.ImgType : setting.ImgType,
ErrMsg: _self.IsNull(setting.ErrMsg) ? _self.DefautlSetting.ErrMsg : setting.ErrMsg,
callback: _self.IsNull(setting.callback) ? _self.DefautlSetting.callback : setting.callback
};
/*
*work:获取文本控件URL
*/
_self.getObjectURL = function(file) {
var url = null;
if (window.createObjectURL != undefined) {
url = window.createObjectURL(file);
} else if (window.URL != undefined) {
url = window.URL.createObjectURL(file);
} else if (window.webkitURL != undefined) {
url = window.webkitURL.createObjectURL(file);
}
return url;
}
/*
*work:绑定事件
*/
_self.Bind = function() {
document.getElementById(_self.Setting.UpBtn).onchange = function() {
if (this.value) {
if (!RegExp("\.(" + _self.Setting.ImgType.join("|") + ")$", "i").test(this.value.toLowerCase())) {
alert(_self.Setting.ErrMsg);
this.value = "";
return false;
}
if (navigator.userAgent.indexOf("MSIE") > -1) {
try {
document.getElementById(_self.Setting.ImgShow).src = _self.getObjectURL(this.files[0]);
} catch (e) {
var div = document.getElementById(_self.Setting.DivShow);
this.select();
top.parent.document.body.focus();
var src = document.selection.createRange().text;
document.selection.empty();
document.getElementById(_self.Setting.ImgShow).style.display = "none";
div.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale)";
div.style.width = _self.Setting.Width + "px";
div.style.height = _self.Setting.Height + "px";
div.filters.item("DXImageTransform.Microsoft.AlphaImageLoader").src = src;
}
} else {
document.getElementById(_self.Setting.ImgShow).src = _self.getObjectURL(this.files[0]);
}
_self.Setting.callback();
}
}
}
/*
*work:执行绑定事件
*/
_self.Bind();
}