jq实现图片上传预览（注意jq版本）

系统管理员 2022-06-04 01:59 320阅读 0赞

一个jq实现上传文件预览插件uploadPreview.js

/*
    *名称:图片上传本地预览插件
    *参数说明: Img:图片ID;Width:预览宽度;Height:预览高度;ImgType:支持文件类型;Callback:选择文件显示图片后回调方法;
    *使用方法: 
    <div>
    <img id="ImgPr" width="120" height="120" /></div>
    <input type="file" id="up" />
    把需要进行预览的IMG标签外 套一个DIV 然后给上传控件ID给予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("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()
                }
            })
        }
    });

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>