To hide the title bar on the frame, you need to set the undecorated property of the specific frame to true.

要隐藏Frame上的Title bar，需要将指定Frame的undecorated属性设为true。

youdao

While Sun added the ability to programmatically iconify the frame in version 1.2, you still couldn't hide the title bar or maximize a frame.

虽然 Sun 在版本 1.2 中添加了通过编程将 Frame 图标化的功能，您仍然无法隐藏 Title bar 或将 Frame 最大化。

youdao