java - 避免 Android 中的物理后退按钮

Question

我想避免 Android 用户玩我的游戏并游戏结束，他们只需单击后退按钮即可返回游戏。

这是我从 GameActivity 跳转到新的 GameOver Activity 的代码。我可以使用什么命令？我只是想回到主要 Activity 而不是游戏 Activity 。

private void checkFails(){
    TextView failsleft = (TextView) findViewById(R.id.fails);
    if(fails < 1){
        failsleft.setText("Fails left: "+fails);
        Intent intent = new Intent(this, GameOverActivity.class);
        startActivity(intent);

    }else{
        failsleft.setText("Fails left: "+fails);
        fails--;
    }
}

Answer 1

如果你的 GameActivity 是由 MainActivity 启动的，你可以使用 extra 来告诉主 Activity 游戏已经结束。因此，您需要使用 startActivityWithResult 启动 GameActivity。

在MainActivity中，使用startActivityForResult()启动GameActivity:

public class MainActivity extends AppCompatActivity {

    ...

    // Request code for handling the GameActivity result
    // make it final so it can be changed.
    private static final int gameOverRequestCode = 777;

    // Start GameActivity
    private void startTheGame() {
      Intent intent = new Intent(this, GameActivity.class);
      // start the GameActivity and wait for the result.
      startActivityForResult(intent, gameOverRequestCode);
    }


    @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) {
      switch (requestCode) {

        // Handle the result from GameActivity.
        // when the result is accepted from GameActivity, start the GameOverActivity.
        case gameOverRequestCode:
          if (resultCode == Activity.RESULT_OK) {
            Intent intent = new Intent(this, GameOverActivity.class);
            startActivity(intent);
          }
          break;
      }
    }

    ...
}

在GameActivity中，游戏结束时发送结果:

private void checkFails(){
    TextView failsleft = (TextView) findViewById(R.id.fails);
    if(fails < 1){
        failsleft.setText("Fails left: "+fails);

        // Send the result back to main activity
        Intent i = getIntent();
        // you can add any extra here, for example, game state.
        // i.putExtra("extra_key", value);
        setResult(Activity.RESULT_OK, i);

        // Finish the GameActivity because we don't need it anymore.
        finish();

    }else{
        failsleft.setText("Fails left: "+fails);
        fails--;
    }
}