将Gutenberg切换到全屏模式需要设置为TRUEfullscreenMode 从core/edit-post 包裹要将适当的脚本排队，请使用enqueue_block_editor_assets 行动挂钩。

function se337302_fullscreen_editor()
{
    $js_code = "jQuery(document).ready(function(){" .
            "   var isFullScreenMode = wp.data.select(\'core/edit-post\').isFeatureActive(\'fullscreenMode\');" .
            "   if ( !isFullScreenMode )" .
            "       wp.data.dispatch(\'core/edit-post\').toggleFeature(\'fullscreenMode\');" .
            "});";
    wp_add_inline_script( \'wp-blocks\', $js_code );

}
add_action( \'enqueue_block_editor_assets\', \'se337302_fullscreen_editor\' );