Question

我有一个在打开主要活动之前显示2秒的启动活动。如果用户在显示启动活动时按下后退按钮，则会关闭启动活动。但不久之后，主要活动[由启动活动触发]开启了。

我不希望这种情况发生。如果在显示启动画面时按下后退按钮，我希望关闭整个应用程序。我该如何做到这一点？

编辑：下面是我的启动活动代码：

    public class Splash2 extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // fullscreen
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);

        // fading transition between activities
        overridePendingTransition(R.anim.fadein, R.anim.fadeout);

        setContentView(R.layout.activity_splash2);
        Thread timer = new Thread() {
            public void run() {
                try {
                    sleep(1500);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                } finally {
                    Intent open = new Intent(
                            "com.example.puzzletimer.HOMESCREEN");
                    startActivity(open);
                }
            }
        };
        timer.start();
    }

    @Override
    protected void onPause() {
        // TODO Auto-generated method stub
        super.onPause();
        finish();
    }

}

Answer 1

只需将此代码添加到您的SplashActivity中......

@Override
public void onBackPressed() {
    super.onBackPressed();
    android.os.Process.killProcess(android.os.Process.myPid());
}

或维护一个标志以确定是否在Thread中启动Activity ...

public class Splash2 extends Activity {

    private volatile boolean interrupt;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // fullscreen
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);

        // fading transition between activities
        overridePendingTransition(R.anim.fadein, R.anim.fadeout);

        setContentView(R.layout.activity_splash2);
        Thread timer = new Thread() {
            public void run() {
                try {
                    sleep(1500);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                } finally {
                    if (!interrupt) {
                        Intent open = new Intent(
                                "com.example.puzzletimer.HOMESCREEN");
                        startActivity(open);
                    }
                }
            }
        };
        timer.start();
    }

    @Override
    protected void onPause() {
        // TODO Auto-generated method stub
        super.onPause();
        finish();
    }

    @Override
    public void onBackPressed() {
        super.onBackPressed();
        interrupt = true;
    }
}

Answer 2

试试这个 -

@Override
public boolean onKeyDown(int keyCode, KeyEvent event)  {
if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {
// do something on back.
this.finish();
return true;
}
return super.onKeyDown(keyCode, event);
}

Answer 3

另一种方法是使用runnable：

在您的Splash2活动中声明处理程序和Runnable：
```
private Handler handler;
private Runnable startMain;
```

在onCreate（）中，初始化它们并将runnable设置为在1.5秒内触发：

handler = new Handler();
startMain = new Runnable() {
    @Override
    public void run() {
        Intent open = new Intent("com.example.puzzletimer.HOMESCREEN");
        startActivity(open);
    }
};      

handler.postDelayed(startMain, 1500);

覆盖onBackPressed（）并简单地取消runnable：

@Override
public void onBackPressed() {
    handler.removeCallbacks(startMain);
    super.onBackPressed();
}

就是这样。如果按下后退键，它将取消runnable并且您的主屏幕将无法运行。

如果在Android中关闭启动活动，如何关闭应用程序

3 个答案: