php – 如何从WordPress插件中的功能下载CSV文件？

我为客户端构建了一个插件,以便他们以CSV文件的形式下载数据.它已经设置好,当用户点击菜单中的链接时,CSV应该只是自动下载.但是,它不会像这样工作,只需将功能作为页面加载到wordpress后端.

这是我的功能的代码：

function download_payment_csv() {
    include 'lib/connection.PHP';

    $csv_output = '';

    $values = $db->query('SELECT * FROM tbPayments ORDER BY date DESC');

    $i=0;

    while ($rowr = MysqL_fetch_row($values)) {
        for ($j=0;$j<$i;$j++) {
            $csv_output .= $rowr[$j].",";
        }
        $csv_output .= "\n";
    }

    header("Pragma: public");
    header("Expires: 0");
    header("Cache-Control: must-revalidate,post-check=0,pre-check=0");
    header("Cache-Control: private",false);
    header("Content-Type: application/octet-stream");
    header("Content-disposition: attachment; filename=\"report.csv\";" );
    header("Content-transfer-encoding: binary");

    echo $csv_output;

}

正如我所说,它只是返回一个空白屏幕.任何帮助将不胜感激！

编辑
所以这是我现在正在使用的代码,从已经说过的代码中抽出来.

function download_payment_csv() {

    include 'lib/connection.PHP';

    $csv_output = '';

    $values = load_payment_csv();

    $fp = fopen("PHP://output","w");

    $file = 'test_export';
    $filename = $file."_".date("Y-m-d_H-i",time());
    header("Content-Type: text/csv");
    header("Content-disposition: attachment; filename=".$filename.".csv");
    // disable caching
    header("Cache-Control: no-cache,no-store,must-revalidate"); // HTTP 1.1
    header("Pragma: no-cache"); // HTTP 1.0
    header("Expires: 0"); // Proxies
    header("Content-transfer-encoding: UTF-8");

    if(count($values) > 0) {
        foreach($values as $result) {
            fputcsv($fp,$result);
        }
    }

    fclose($fp);

}

这会产生一个CSV,但是它有一个问题.问题是,当查看页面时,它不会将其下载为CSV,它只将CSV的内容输出到页面.但是,将此函数添加到插件的顶部：

add_action('admin_init','download_payment_csv');

这样当菜单链接被点击时触发下载,这是很好的.但它会为插件中的每个菜单项触发它,这是错误的.仅当点击下载链接时才触发.

$results = $wpdb->get_results("SHOW COLUMNS FROM $table" );
if(count($results) > 0){
    foreach($results as $result){
        $csv_output .= str_replace('_',' ',$result->Field).","; //,or ;      
    }
}
$csv_output .= "\n";

$results = $wpdb->get_results("SELECT * FROM $table",ARRAY_A );
if(count($results) > 0){
    foreach($results as $result){
        $result = array_values($result);
        $result = implode(",",$result);
        $csv_output .= $result."\n"; 
    }
}

$filename = $file."_".date("Y-m-d_H-i",time());
header("Content-type: application/vnd.ms-excel");
header("Content-disposition: csv" . date("Y-m-d") . ".csv");
header( "Content-disposition: filename=".$filename.".csv");
print $csv_output;
exit;