浏览器图片选择预览、旋转、批量上传的JS代码实现

// 上传回调
        // resultList -> ['file1', 'file2'] 为上传成功的file name
        var uploadCallback = function(resultList){
            console.log(JSON.stringify(resultList));

            var i = 0;
            for(; i < resultList.length; i++){
                var index = resultList[i].substr('file'.length);
                $(':checkbox[value=' + index + ']').parent().parent().remove();
            }
        };

        $(function(){
            // 保存图片旋转的角度，以便提交给服务端处理
            var rotateAng = {};
            // 用于命名后缀的序号
            var cc = 0;

            // 如果是chrome/ff，需要用file api去生成img
            var genImgTpl = function(input, index){
                return '<img src="/webx/public/1.png" class="main" id="img' + index + '" />';
            };

            var readImgFromInput = function(_input, index){
                var inputDom = _input[0];
                // chrome/ff
                if(inputDom['files']){
                    var reader = new FileReader();
                    reader.onload = function(e){
                        $('img.main:last').attr({src : e.target.result});
                    }
                    reader.readAsDataURL(inputDom['files'][0]);
                }else{
                    var src = _input[0].value;

                    var imgDom = $('#img' + index);
                    imgDom.attr('src-old', src);
                    imgDom.css({
                        float: 'left',
                        position: 'relative',
                        overflow: 'hidden',
                        width: '195px',
                        height: '195px'
                    });

                    imgDom.css({'filter': "progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled='true',sizingMethod='scale',src=/"" + src + "/")"});
                }
            };

            var showImg = function(_input){
                var index = ++cc;

                _input.addClass('hide');
                _input.attr('name', 'file' + index);
                _input.attr('data-index', index);

                var iframeWin = $('#choose')[0].contentWindow;
                iframeWin.addInput(_input);

                var tpl = '<div>' + genImgTpl(_input, index) +
                    '<span class="choose"><input type="checkbox" value="' + index + '" checked="true" /></span>' +
                    '<span class="opts turn-right"><img src="img/rightBtn.png" /></span>' +
                    '</div>';
                $('#imgDiv').append(tpl);

                readImgFromInput(_input, index);
            };
            var addAnother = function(){
                $('#uploadBtn').before('<input type="file" name="file" />');
            };

            // input[type=file]的绑定事件
            $('#uploadDiv input').live('change', function(){
                var path = this.value;
                if(!path){
                    return;
                }

                showImg($(this));
                addAnother();
            });

            // 可以在checkbox时候remove input
//            $('#imgDiv input:checkbox').live('change', function(){
//                var isChecked = $(this).is(':checked');
//                console.log(isChecked);
//            });

            $('#imgDiv span.turn-right').live('click', function(){
                // 上次旋转的角度
                var index = $(this).siblings('span.choose').find('input').val();
                var oldAng = rotateAng[index] || 0;
                var newAng = oldAng + 90;
                rotateAng[index] = newAng;

                $('#img' + index).rotate(90);
            });

            // 表单提交时候根据checkbox，删除未choose的input[type=file]
            $('#uploadBtn').click(function(){
                var choosedNum = $('#imgDiv input:checkbox').filter(':checked').length;
                if(!choosedNum){
                    alert('请选择上传文件！');
                    return false;
                }

                // 选中的序号数组
                var choosedIndexList = $('#imgDiv input:checkbox').filter(':checked').map(function(){
                    return this.value;
                }).get();

                // 两个iframe，一个用于保存选择的input[type=file]
                // 一个用于form upload
                var uploadIframe = $('#upload')[0].contentWindow;
                var chooseIframe = $('#choose')[0].contentWindow;

                var i = 0;
                for(; i < choosedIndexList.length; i++){
                    var index = choosedIndexList[i];
                    var inputFile = chooseIframe.$('#uploadDiv input').filter('[data-index=' + index + ']');
                    uploadIframe.$('#uploadForm').append(inputFile);

                    // 旋转度数
                    var ang = rotateAng[index] || 0;
                    if(ang % 360 != 0){
                        var tplInput = '<input type="hide" name="ang' + index + '" value="' + ang + '" />';
                        uploadIframe.$('#uploadForm').append(tplInput);
                    }
                }

                uploadIframe.doUpload();

                return false;
            });
        });