檔名 jquery.uploadView.js

// 圖片上傳前預覽外掛
//Power By 勾國印
//QQ:245629560
//Blog:http://www.gouguoyin.cn
(function($){  
    $.fn.uploadView = function(options){
        var defaults = {
            uploadBox: '.js_uploadBox', //設定上傳框容器
            showBox : '.js_showBox', //設定顯示預覽圖片的容器
            /*width : 200, //設定預覽圖片的寬度*/
 

            height: 240, //設定預覽圖片的高度
            allowType: ["gif", "jpeg", "jpg", "bmp", "png"], 
            maxSize: 1, //設定允許上傳圖片的最大尺寸，單位M
            success:$.noop //上傳成功時的回撥函式
        };
        var config = $.extend(defaults, options);

        var showBox = config.showBox;
        var uploadBox = config.uploadBox;
        var
 
 width = config.width;
        var height = config.height;
        var allowType = config.allowType;
        var maxSize = config.maxSize;

        var success = config.success;

        $(this).each(function(i){
            $(this).change(function(e){
              handleFileSelect($(this), width, height, allowType, maxSize, success);
            });
        });

        var
 
 handleFileSelect = function(obj, _w, _h, _type, _size, _callback){

              if (typeof FileReader == "undefined") {
                return false;
              }
              var thisClosest = obj.closest(uploadBox);
              if (typeof thisClosest.length == "undefined") {
                return;
              }

              var files = obj[0].files;
              var f = files[0];
              if (!isAllowFile(f.name, _type)) {
                alert("圖片型別必須是" + _type.join("，") + "中的一種"); 
                return false;
              }

              var fileSize = f.size;

              var maxSize = _size*1024*1024;

              if(fileSize > maxSize){
                alert('上傳圖片超出允許上傳大小');
                return false;
              }

              var reader = new FileReader();
              reader.onload = (function(theFile){
                      return function (e) {
                        var tmpSrc = e.target.result;
                        if (tmpSrc.lastIndexOf('data:base64') != -1) {
                          tmpSrc = tmpSrc.replace('data:base64', 'data:image/jpeg;base64');
                        } else if (tmpSrc.lastIndexOf('data:,') != -1) {
                          tmpSrc = tmpSrc.replace('data:,', 'data:image/jpeg;base64,');
                        }

                        var img = '<img src="' + tmpSrc + '"/>';
                        //consoleLog(reader, img);
                        thisClosest.find(showBox).show().html(img);
                        if (_w && _h) {
                          cssObj = { 'width':_w+'px', 'height':_h+'px' };
                        } else if (_w) {
                          cssObj = { 'width':_w+'px' };
                        } else if (_h) {
                          cssObj = { 'height':_h+'px' };
                        } else {
                          cssObj = { 'max-width':'100%', 'max-height':'100%' };
                        }
                        thisClosest.find(showBox+" img").css( cssObj );
                        _callback();
                     };
              })(f)
              reader.readAsDataURL(f);

        }
        //獲取上傳檔案的字尾名
        var getFileExt = function(fileName){
              if (!fileName) {
                    return '';
                  }

                  var _index = fileName.lastIndexOf('.');
                  if (_index < 1) {
                    return '';
                  }

                  return fileName.substr(_index+1);
            };
        //是否是允許上傳檔案格式   
        var isAllowFile = function(fileName, allowType){

              var fileExt = getFileExt(fileName).toLowerCase();
              if (!allowType) {
                allowType = ['jpg', 'jpeg', 'png', 'gif', 'bmp'];
              }

              if ($.inArray(fileExt, allowType) != -1) {
                return true;
              }
              return false;

        }       

    };


})(jQuery);

jQuery.extend({ 
unselectContents: function(){ 
    if(window.getSelection) 
        window.getSelection().removeAllRanges(); 
    else if(document.selection) 
        document.selection.empty(); 
    } 
}); 
jQuery.fn.extend({ 
    selectContents: function(){ 
        $(this).each(function(i){ 
            var node = this; 
            var selection, range, doc, win; 
            if ((doc = node.ownerDocument) && (win = doc.defaultView) && typeof win.getSelection != 'undefined' && typeof doc.createRange != 'undefined' && (selection = window.getSelection()) && typeof selection.removeAllRanges != 'undefined'){ 
                range = doc.createRange(); 
                range.selectNode(node); 
                if(i == 0){ 
                    selection.removeAllRanges(); 
                } 
                selection.addRange(range); 
            } else if (document.body && typeof document.body.createTextRange != 'undefined' && (range = document.body.createTextRange())){ 
                range.moveToElementText(node); 
                range.select(); 
            } 
        }); 
    }, 

    setCaret: function(){ 
        if(!$.browser.msie) return; 
        var initSetCaret = function(){ 
            var textObj = $(this).get(0); 
            textObj.caretPos = document.selection.createRange().duplicate(); 
        }; 
        $(this).click(initSetCaret).select(initSetCaret).keyup(initSetCaret); 
    }, 

    insertAtCaret: function(textFeildValue){ 
        var textObj = $(this).get(0); 
        if(document.all && textObj.createTextRange && textObj.caretPos){ 
            var caretPos=textObj.caretPos; 
            caretPos.text = caretPos.text.charAt(caretPos.text.length-1) == '' ? 
            textFeildValue+'' : textFeildValue; 
        } else if(textObj.setSelectionRange){ 
            var rangeStart=textObj.selectionStart; 
            var rangeEnd=textObj.selectionEnd; 
            var tempStr1=textObj.value.substring(0,rangeStart); 
            var tempStr2=textObj.value.substring(rangeEnd); 
            textObj.value=tempStr1+textFeildValue+tempStr2; 
            textObj.focus(); 
            var len=textFeildValue.length; 
            textObj.setSelectionRange(rangeStart+len,rangeStart+len); 
            textObj.blur(); 
        }else{ 
            textObj.value+=textFeildValue; 
        } 
    } 
});

使用方法如下：
首先下載原始碼，在模板頁加入上傳框，結構如下：

<div class="control-group js_uploadBox">
    <div class="btn-upload">
      <a href="javascript:void(0);"><i class="icon-upload"></i><span class="js_uploadText">上傳</span>圖片</a>
      <input class="js_upFile" type="file" name="cover">
    </div>
    <div class="js_showBox "><img class="js_logoBox" src="" width="100px" ></div>
 </div>

複製程式碼
然後再引入外掛jquery.uploadView.js（注意先後順序，jquery必須要在外掛之前引入）然後在模板頁配置外掛引數，配置如下

$(".js_upFile").uploadView({
    uploadBox: '.js_uploadBox',//設定上傳框容器
    showBox : '.js_showBox',//設定顯示預覽圖片的容器
    width : 100, //預覽圖片的寬度，單位px
    height : 100, //預覽圖片的高度，單位px
    allowType: ["gif", "jpeg", "jpg", "bmp", "png"], //允許上傳圖片的型別
    maxSize :2, //允許上傳圖片的最大尺寸，單位M
    success:function(e){
        $(".js_uploadText").text('更改');
        alert('圖片上傳成功');
    }
 });