通过Javascript，您可以弹出媒体，并在选择时将图像URL更新到文本框。下面是代码。

var custom_uploader;
jQuery(\'<Should-be-a-button-selector>\').click(function(e) {
    e.preventDefault();
    //If the uploader object has already been created, reopen the dialog
    if (custom_uploader) {
        custom_uploader.open();
        return;
    }

    //Extend the wp.media object
    custom_uploader = wp.media.frames.file_frame = wp.media({
        title: \'Choose Image\',
        button: {
            text: \'Choose Image\'
        },
        multiple: false
    });

    //When a file is selected, grab the URL and set it as the text field\'s value
    custom_uploader.on(\'select\', function() {
        attachment = custom_uploader.state().get(\'selection\').first().toJSON();
        jQuery(\'#Cat_meta[img]\').val(attachment.url);


    //Open the uploader dialog
    custom_uploader.open();
});