在layout中輸入項(xiàng)老師的代碼后，出現(xiàn)下面這樣的提示應(yīng)該怎么解決？ ?麻煩老師和各位學(xué)友指點(diǎn)一下，謝謝先啦。

You must specifiy a valid layout reference. The layout ID @layout/left_menu is not valid.

Exception details are logged in Window > Show View > Error Log