使用EasyUI datagrid-export.js导出Excel,适用于多级表头

原文：https://www.cnblogs.com/xiamengz/p/13163006.html

原datagrid-export.js导出Excel只能导一级表头的Excel,因项目需要，对其进行了修改优化。

在js文件中，主要修改了toHtml方法。导出Excel步骤：先将datagrid的数据生成html的table,根据table样式导出到Excel文件。

方法：

(function($){
    function getRows(target){
        var state = $(target).data(\'datagrid\');
        if (state.filterSource){
            return state.filterSource.rows;
        } else {
            return state.data.rows;
        }
    }
    function getFooterRows(target){
        var state = $(target).data(\'datagrid\');
        return state.data.footer || [];
    }
    function toHtml(target, rows, footer, caption) {
        rows = rows || getRows(target);
        rows = rows.concat(footer || getFooterRows(target));
        var dg = $(target);
        var data = [\'<table border="1" rull="all" style="border-collapse:collapse">\'];
        var fields = dg.datagrid(\'getColumnFields\', true).concat(dg.datagrid(\'getColumnFields\', false));
        //获取所有列信息
        var cc = dg.datagrid(\'options\').columns;
        /*
        var columns = dg.datagrid(\'options\').columns[0];
        var fields =[];
        var j = 0;
        //剔除hidden为true的字段
        for(var i=0;i<columns.length;i++){
            if(columns[i].hidden){}
            else{
                fields[j]=columns[i].field;
                j++;
            }
        }
        */

        var trStyle = \'height:32px\';
        var tdStyle0 = \'vertical-align:middle;padding:0 4px\';
        if (caption) {
            data.push(\'<caption>\' + caption + \'</caption>\');
        }
        //写入表头信息，先判断是否为多级表头
        for (var j = 0; j < cc.length; j++) {
            data.push(\'<tr style="\' + trStyle + \'">\');
            var cols = cc[j];
            for (var i = 0; i < cols.length; i++) {
                //判断是否未隐藏字段
                if (cols[i].hidden == true) {
                    continue;
                }
                var tdStyle = tdStyle0 + \';width:\' + cols[i].boxWidth + \'px;\';
                tdStyle += \';text-align:\' + (cols[i].halign || cols[i].align || \'\');
                //定义行列信息，初始化行和列的值为1
                var colspans = 1;
                var rowspans = 1;
                if (cols[i].rowspan === undefined) {
                } else {
                    rowspans = cols[i].rowspan;
                }
                if (cols[i].colspan === undefined) {
                } else {
                    colspans = cols[i].colspan;
                }
                data.push(\'<td style="\' + tdStyle + \'" colspan="\' + colspans + \'" rowspan="\' + rowspans + \'">\' + cols[i].title + \'</td>\');
            }
            data.push(\'</tr>\');
        }

        //原方法
        /*
        data.push(\'<tr style="\'+trStyle+\'">\');
        for(var i=0; i<fields.length; i++){
            var col = dg.datagrid(\'getColumnOption\', fields[i]);
            var tdStyle = tdStyle0 + \';width:\'+col.boxWidth+\'px;\';
            tdStyle += \';text-align:\'+(col.halign||col.align||\'\');
            data.push(\'<td style="\'+tdStyle+\'">\'+col.title+\'</td>\');
        }
        data.push(\'</tr>\');
        */

        $.map(rows, function (row) {
            data.push(\'<tr style="\' + trStyle + \'">\');
            for (var i = 0; i < fields.length; i++) {
                var field = fields[i];
                var col = dg.datagrid(\'getColumnOption\', field);
                if (col.hidden == true) {
                    continue;
                }
                var value = row[field];
                if (value == undefined) {
                    value = \'\';
                }
                var tdStyle = tdStyle0;
                tdStyle += \';text-align:\' + (col.align || \'\');
                data.push(
                    \'<td style="\' + tdStyle + \'">\' + value + \'</td>\'
                );
            }
            data.push(\'</tr>\');
        });
        data.push(\'</table>\');
        return data.join(\'\');
    }

    function toArray(target, rows){
        rows = rows || getRows(target);
        var dg = $(target);
        var fields = dg.datagrid(\'getColumnFields\',true).concat(dg.datagrid(\'getColumnFields\',false));
        var data = [];
        var r = [];
        for(var i=0; i<fields.length; i++){
            var col = dg.datagrid(\'getColumnOption\', fields[i]);
            r.push(col.title);
        }
        data.push(r);
        $.map(rows, function(row){
            var r = [];
            for(var i=0; i<fields.length; i++){
                r.push(row[fields[i]]);
            }
            data.push(r);
        });
        return data;
    }

    function print(target, param){
        var title = null;
        var rows = null;
        var footer = null;
        var caption = null;
        if (typeof param == \'string\'){
            title = param;
        } else {
            title = param[\'title\'];
            rows = param[\'rows\'];
            footer = param[\'footer\'];
            caption = param[\'caption\'];
        }
        var newWindow = window.open(\'\', \'\', \'width=800, height=500\');
        var document = newWindow.document.open();
        var content = 
            \'<!doctype html>\' +
            \'<html>\' +
            \'<head>\' +
            \'<meta charset="utf-8">\' +
            \'<title>\'+title+\'</title>\' +
            \'</head>\' +
            \'<body>\' + toHtml(target, rows, footer, caption) + \'</body>\' +
            \'</html>\';
        document.write(content);
        document.close();
        newWindow.print();
    }

    function b64toBlob(data){
        var sliceSize = 512;
        var chars = atob(data);
        var byteArrays = [];
        for(var offset=0; offset<chars.length; offset+=sliceSize){
            var slice = chars.slice(offset, offset+sliceSize);
            var byteNumbers = new Array(slice.length);
            for(var i=0; i<slice.length; i++){
                byteNumbers[i] = slice.charCodeAt(i);
            }
            var byteArray = new Uint8Array(byteNumbers);
            byteArrays.push(byteArray);
        }
        return new Blob(byteArrays, {
            type: \'\'
        });
    }

    function toExcel(target, param){
        var filename = null;
        var rows = null;
        var footer = null;
        var caption = null;
        var worksheet = \'Worksheet\';
        if (typeof param == \'string\'){
            filename = param;
        } else {
            filename = param[\'filename\'];
            rows = param[\'rows\'];
            footer = param[\'footer\'];
            caption = param[\'caption\'];
            worksheet = param[\'worksheet\'] || \'Worksheet\';
        }
        var dg = $(target);
        var uri = \'data:application/vnd.ms-excel;base64,\'
        , template = \'<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns="http://www.w3.org/TR/REC-html40"><meta http-equiv="content-type" content="application/vnd.ms-excel; charset=UTF-8"><head><!--[if gte mso 9]><xml><x:ExcelWorkbook><x:ExcelWorksheets><x:ExcelWorksheet><x:Name>{worksheet}</x:Name><x:WorksheetOptions><x:DisplayGridlines/></x:WorksheetOptions></x:ExcelWorksheet></x:ExcelWorksheets></x:ExcelWorkbook></xml><![endif]--></head><body>{table}</body></html>\'
        , base64 = function (s) { return window.btoa(unescape(encodeURIComponent(s))) }
        , format = function (s, c) { return s.replace(/{(\w+)}/g, function (m, p) { return c[p]; }) }

        var table = toHtml(target, rows, footer, caption);
        var ctx = { worksheet: worksheet, table: table };
        var data = base64(format(template, ctx));
        if (window.navigator.msSaveBlob){
            var blob = b64toBlob(data);
            window.navigator.msSaveBlob(blob, filename);
        } else {
            var alink = $(\'<a style="display:none"></a>\').appendTo(\'body\');
            alink[0].href = uri + data;
            alink[0].download = filename;
            alink[0].click();
            alink.remove();
        }
    }

    $.extend($.fn.datagrid.methods, {
        toHtml: function(jq, rows){
            return toHtml(jq[0], rows);
        },
        toArray: function(jq, rows){
            return toArray(jq[0], rows);
        },
        toExcel: function(jq, param){
            return jq.each(function(){
                toExcel(this, param);
            });
        },
        print: function(jq, param){
            return jq.each(function(){
                print(this, param);
            });
        }
    });
})(jQuery);

调用：

 if ($(\'#divInfo\').datagrid(\'getData\')) {
            $(\'#divInfo\').datagrid(\'toExcel\', \'导出文件名称.xls\');
        } 

备注：

//取值为formatter中data的值
 formatter: function (value,data) {      
                           data.Name=\'你好\'
                            return data.Name;
                        }