jquery 图片预览插件

jQuery.fn.extend({
            uploadPreview: function (opts) {
                var _self = this,
                    _this = $(this);
                opts = jQuery.extend({
                    Img: "ImgPr",
                    Width: 100,
                    Height: 100,
                    ImgType: ["gif", "jpeg", "jpg", "bmp", "png"],
                    Callback: function () { }
                }, opts || {});
                _self.getObjectURL = function (file) {
                    var url = null;
                    if (window.createObjectURL != undefined) {
                        url = window.createObjectURL(file)
                    } else if (window.URL != undefined) {
                        url = window.URL.createObjectURL(file)
                    } else if (window.webkitURL != undefined) {
                        url = window.webkitURL.createObjectURL(file)
                    }
                    return url
                };
                _this.change(function () {
                    if (this.value) {
                        if (!RegExp("\.(" + opts.ImgType.join("|") + ")$", "i").test(this.value.toLowerCase())) {
                            alert("选择文件错误,图片类型必须是" + opts.ImgType.join("，") + "中的一种");
                            this.value = "";
                            return false
                        }
                        if ($.browser.msie) {
                            try {
                                $("#" + opts.Img).attr('src', _self.getObjectURL(this.files[0]))
                            } catch (e) {
                                var src = "";
                                var obj = $("#" + opts.Img);
                                var div = obj.parent("div")[0];
                                _self.select();
                                if (top != self) {
                                    window.parent.document.body.focus()
                                } else {
                                    _self.blur()
                                }
                                src = document.selection.createRange().text;
                                document.selection.empty();
                                obj.hide();
                                obj.parent("div").css({
                                    'filter': 'progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale)',
                                    'width': opts.Width + 'px',
                                    'height': opts.Height + 'px'
                                });
                                div.filters.item("DXImageTransform.Microsoft.AlphaImageLoader").src = src
                            }
                        } else {
                            $("#" + opts.Img).attr('src', _self.getObjectURL(this.files[0]))
                        }
                        opts.Callback()
                    }
                })
            }
        });