0

我有两个整数变量，它们充当计数器和按钮。我还有 2 个链接的切换按钮，因此一次只有 1 个处于活动状态。单击“添加”按钮时，我想根据选中的切换按钮将 1 添加到计数器变量；即如果选中toggle1，则将1添加到counter1

我已经这样尝试过，没有任何乐趣。任何帮助都会很棒。

Counter1= 0;
Counter2= 0;
Add1 = (Button) findViewById(R.id.add1Button);
toggle1 = (ToggleButton) findViewById(R.id.toggle1Button);
toggle2 = (ToggleButton) findViewById(R.id.toggle2Button);
counter1Display= (TextView) findViewById(R.id.count1);
counter2Display= (TextView) findViewById(R.id.count2);

Add1.setOnClickListener(new View.OnClickListener() {

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
    if (toggle1.isChecked()) {
        Counter1 += 1;
        counter1Display.setText("" + Counter1);

    }
    if (toggle2.isChecked()) {
        Counter2 += 1;
        counter2Display.setText("" + Counter2);
    }
}
});

这是 LogCat

07-28 11:44:01.156: D/AndroidRuntime(320): Shutting down VM
07-28 11:44:01.156: W/dalvikvm(320): threadid=1: thread exiting with uncaught exception (group=0x40015560)
07-28 11:44:01.176: E/AndroidRuntime(320): FATAL EXCEPTION: main
07-28 11:44:01.176: E/AndroidRuntime(320): java.lang.NullPointerException
07-28 11:44:01.176: E/AndroidRuntime(320):  at com.kh.counterapp.MainActivity$2.onClick(MainActivity.java:90)
07-28 11:44:01.176: E/AndroidRuntime(320):  at android.view.View.performClick(View.java:2485)
07-28 11:44:01.176: E/AndroidRuntime(320):  at android.view.View$PerformClick.run(View.java:9080)
07-28 11:44:01.176: E/AndroidRuntime(320):  at android.os.Handler.handleCallback(Handler.java:587)
07-28 11:44:01.176: E/AndroidRuntime(320):  at android.os.Handler.dispatchMessage(Handler.java:92)
07-28 11:44:01.176: E/AndroidRuntime(320):  at android.os.Looper.loop(Looper.java:123)
07-28 11:44:01.176: E/AndroidRuntime(320):  at android.app.ActivityThread.main(ActivityThread.java:3683)
07-28 11:44:01.176: E/AndroidRuntime(320):  at java.lang.reflect.Method.invokeNative(Native Method)
07-28 11:44:01.176: E/AndroidRuntime(320):  at java.lang.reflect.Method.invoke(Method.java:507)
07-28 11:44:01.176: E/AndroidRuntime(320):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
07-28 11:44:01.176: E/AndroidRuntime(320):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
07-28 11:44:01.176: E/AndroidRuntime(320):  at dalvik.system.NativeStart.main(Native Method)
4

2 回答 2

1

通过检查你的日志我发现

java.lang.NullPointerException

看起来您没有在 onCreate() 方法中设置正确的布局。

设置内容视图（R.layout.example）；

编辑

您是否在单击添加按钮或应用程序在开始前崩溃时遇到此异常？

于 2014-07-28T11:56:25.263 回答
0

检查此代码..

    counter1=0;
    counter2=0;
    tg1 = (ToggleButton) findViewById(R.id.toggleButton1);
    tg2 = (ToggleButton) findViewById(R.id.toggleButton2);
    bt1 = (Button) findViewById(R.id.button1);
    counter1Display= (TextView) findViewById(R.id.count1);
    counter2Display= (TextView) findViewById(R.id.count2);


    tg1.setOnCheckedChangeListener(new OnCheckedChangeListener() {

        @Override
        public void onCheckedChanged(CompoundButton v,
                boolean isChecked) {
            if (tg2.isChecked()) {
                tg2.setChecked(false);
            }
        }
    });
    tg2.setOnCheckedChangeListener(new OnCheckedChangeListener() {

        @Override
        public void onCheckedChanged(CompoundButton v,
                boolean isChecked) {
            if (tg1.isChecked()) {
                tg1.setChecked(false);
            }
        }
    });

    bt1.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            if (tg1.isChecked()) {
                counter1=counter1+1;
                counter1Display.setText(""+counter1);

            } else if (tg2.isChecked()) {
                counter2=counter2+1;
                counter2Display.setText(""+counter2);
            }

        }
    });
于 2014-07-28T11:54:57.270 回答