Android run error - Your project contains error(s), please fix them before running your application.

1. 當按下"Run"時發現Error訊息，顯示"Your project contains error(s), please fix them before running your application."。

2. 使用滑鼠點選project，在按"滑鼠右鍵" > "Properties" 。

3. 選擇"Java Build Path" > "Libraies"，修改android path，至"..\sdk\extras\android\support\v4"，如下圖所示。