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 + ';' + 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 + ';'+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;
                        }