PHP导出Excel、CSV文件，并解决显示不正常等问题

最近一直在折腾PHP，无意间想实现个导出表格的功能。
不料用了header声明后的表格中文是乱码的，后来通过转字符、添加字母符号、style等方法才得以让excel导出后显示正常了。

为了解决部分MySQL环境设置问题，又添加了一个CSV的导出方法。

导出Excel代码

header("Content-type:application/vnd.ms-excel;charset=UTF-8");
header("Content-Disposition:attachment;filename=xxxxx.xls");

//输出标题
echo "<table border='1'>";

echo   "<th>".mb_convert_encoding($str, "GBK","UTF-8")."</th>"; 
echo   "<th>".mb_convert_encoding($str, "GBK","UTF-8")."</th>";
echo   "<th>".mb_convert_encoding($str, "GBK","UTF-8")."</th>";
#....

//输出每行的内容
for ($i=0; $i < count($Data); $i++) { 
    echo "<tr>";
    for ($n=0; $n < count($Data[$i]); $n++) { 

                //添加 style='vnd.ms-excel.numberformat:@' 将内容作为字符串识别

        echo "<td style='vnd.ms-excel.numberformat:@'>";
        echo mb_convert_encoding($Data[$i][$n],"GBK","UTF-8");
        echo "</td>";
    }
    echo "</tr>";
}
echo "</table>";

导出CSV代码

/**
 * 导出CSV文件
 * @param string $fileName    文件名字
 * @param string|array $data 导出数据，csv格式的字符串|数值数组
 * @param string $to_encoding 目标转换编码
 * @param string $from_encoding 当前编码
 */
function exportCSV($fileName = '', $data = '', $to_encoding = 'gb2312', $from_encoding = 'utf-8') {
    $fileName = empty($fileName) ? date('YmdHis') : $fileName;
    // 文件标签
    Header("Content-type: application/octet-stream");
    header("Content-type: application/vnd.ms-excel; charset=$from_encoding");
    Header("Content-Disposition: attachment; filename=$fileName.csv");

    $str = '';
    if($data) {
        if(is_array($data)) {
            foreach ($data as $v) {
                if(is_array($v)) {
                    foreach ($v as $vo) {
                        $str .= (is_numeric($vo) ? "'".$vo : $vo."").",";
                    }
                    $str = trim($str, ",")."\r\n";
                } else {
                    $str .= (is_numeric($v) ? "'".$v : $v).",";
                }
            }
            $str = trim($str, ",")."\r\n";
        } else {
            $str = $data;
        }
    }

    echo mb_convert_encoding($str, "gb2312", "utf-8");
    exit;
}


exportCSV($fileName=$str,$data = $Data);

?>