Question

我写关于条件的代码，如果同一行中的按钮具有相同的图标图像，则弹出该操作的消息框。但是，如果我单击按钮，它将显示错误（线程“ AWT-EventQueue-0”中的异常java.lang.NullPointerException），并且操作未响应。这是代码：


if(jButton3.getIcon().toString() == "resources/x-mark-300x300.png" && jButton2.getIcon().toString() == "resources/x-mark-300x300.png" && jButton1.getIcon().toString() == "resources/x-mark-300x300.png"){
           JOptionPane.showMessageDialog(null,"Cie Menang !");
       } else if(jButton3.getIcon().toString() == "resources/x-mark-300x300.png" && jButton5.getIcon().toString() == "resources/x-mark-300x300.png" && jButton7.getIcon().toString() == "resources/x-mark-300x300.png"){
           JOptionPane.showMessageDialog(null,"Cie Menang !");
       } else if(jButton3.getIcon().toString() == "resources/x-mark-300x300.png" && jButton6.getIcon().toString() == "resources/x-mark-300x300.png" && jButton9.getIcon().toString() == "resources/x-mark-300x300.png"){
           JOptionPane.showMessageDialog(null,"Cie Menang !");
       }

jButton具有关于相同图标图像的条件时发生错误

0 个答案: