的Java Slic2D erorr

Question

当我添加以下代码：

otionHover = false; 
    if(optionRect.contains(Mouse.getX(), Mouse.getY())) { 
     otionHover = true; 
     if(Mouse.isButtonDown(0)) { 
      System.out.println("The button was pressed!"); 
     } 
    } 

我得到的错误：

Exception in thread "main" java.lang.NullPointerException at lt.CobaltPlanet.nelixus.state.GameMenu.init(GameMenu.java:26) at lt.CobaltPlanet.nelixus.Main.initStatesList(Main.java:55) at org.newdawn.slick.state.StateBasedGame.init(StateBasedGame.java:164) at org.newdawn.slick.AppGameContainer.setup(AppGameContainer.java:393) at org.newdawn.slick.AppGameContainer.start(AppGameContainer.java:317) at lt.CobaltPlanet.nelixus.Main.main(Main.java:74)

Answer 1

optionRect为空。确保为它分配一些东西，可能是一个矩形。

optionRect = new Rectangle(x, y, width, height); 

是你需要的。只需添加适当的值，它应该工作。