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jq實現圖片上傳預覽(注意jq版本)

一個jq實現上傳檔案預覽外掛uploadPreview.js

/*
*名稱:圖片上傳本地預覽外掛
*引數說明: Img:圖片ID;Width:預覽寬度;Height:預覽高度;ImgType:支援檔案型別;Callback:選擇檔案顯示圖片後回撥方法;
*使用方法: 
<div>
<img id="ImgPr" width="120" height="120" /></div>
<input type="file" id="up" />
把需要進行預覽的IMG標籤外 套一個DIV 然後給上傳控制元件ID給予uploadPreview事件
$("#up").uploadPreview({ Img: "ImgPr", Width: 120, Height: 120, ImgType: ["gif", "jpeg", "jpg", "bmp", "png"], Callback: function () { }});
*/
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("選擇檔案錯誤,圖片型別必須是" + opts.ImgType.join(",") + "中的一種");
                    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()
            }
        })
    }
});

使用:
<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<script type="text/javascript" src="lib/js/jq1.7.js"></script>
	<script type="text/javascript" src="lib/js/uploadPreview.js"></script>
</head>
<body>
	<div>
		<img id="ImgPr" width="120" height="120" /></div>
	<input type="file" id="up" />
	<script type="text/javascript">
		$(function(){
			$("#up").uploadPreview({ Img: "ImgPr", Width: 120, Height: 120, ImgType: ["gif", "jpeg", "jpg", "bmp", "png"], Callback: function () { }});
		})
	</script>
</body>
</html>