Question

JAVA 关闭对话框 出错

public class TankClient extends Frame {
……
MyTankDeadDialog mtdd = new MyTankDeadDialog(this, myTank, "死亡", true);
……
public void ClosedDialog()
{
mtdd.setVisible(false);

}

}

public class MyTankDeadDialog extends Dialog {
……
public MyTankDeadDialog(TankClient tc,Tank k, String title, boolean modal) {
super(tc, title, modal);
this.k = k;
……

btn1.addActionListener(new Monitor());
btn2.addActionListener(new Monitor());
……
}
class Monitor implements ActionListener {

public void actionPerformed(ActionEvent e) {

if(e.getSource() == dp.btn1) {
//tc.BringToLife();
k.live = true;
k.life = k.fullLife;

tc.ClosedDialog();//这句*******************************

}

if(e.getSource() == dp.btn2) {
System.exit(0);
}
}

}

java.lang.NullPointerException！难道这样调用不能初始化吗？请问该如何修正？
在类 MyTankDeadDialog 中已经申明了 TankClient tc;

Answer 1

不能。将内部类创建一个有参构造方法，将tc传进去。