Question

我正在使用Android生命周期，我发现一个似乎记录不佳的行为（或者我只是做错了）。

https://developer.android.com/reference/android/app/Activity.html#onCreateOptionsMenu(android.view.Menu)中指定的onCreateOptionsMenu方法应该只调用一次，但在方向更改期间打印两次。

以下是创建流日志，您可以看到在onPostResume方法之后立即调用onCreateOptionsMenu方法：

 [...]
 SimpleActivity >>> onStart
 SimpleActivity <<< onStart
 SimpleFragment >>> onStart
 SimpleFragment <<< onStart
 SimpleActivity >>> onPostCreate
 SimpleActivity <<< onPostCreate
 SimpleActivity >>> onResume
 SimpleActivity <<< onResume
 SimpleFragment >>> onResume
 SimpleFragment <<< onResume
 SimpleActivity >>> onPostResume
 SimpleActivity <<< onPostResume
 SimpleActivity >>> onCreateOptionsMenu
 SimpleActivity <<< onCreateOptionsMenu
 SimpleFragment >>> onCreateOptionsMenu
 SimpleFragment <<< onCreateOptionsMenu
 [...]

但是当由于方向改变而恢复状态时，也会在onRestoreInstanceState方法之后调用它：

 [...]
 SimpleActivity >>> onStart
 SimpleActivity <<< onStart
 SimpleFragment >>> onStart
 SimpleFragment <<< onStart
 SimpleActivity >>> onRestoreInstanceState
 SimpleActivity >>>    onCreateOptionsMenu
 SimpleActivity <<<    onCreateOptionsMenu
 SimpleFragment >>>    onCreateOptionsMenu
 SimpleFragment <<<    onCreateOptionsMenu
 SimpleActivity >>>    onPrepareOptionsMenu
 [...]
 SimpleActivity <<< onRestoreInstanceState
 SimpleActivity >>> onPostCreate
 SimpleActivity <<< onPostCreate
 SimpleActivity >>> onResume
 SimpleActivity <<< onResume
 SimpleFragment >>> onResume
 SimpleFragment <<< onResume
 SimpleActivity >>> onPostResume
 SimpleActivity <<< onPostResume
 SimpleActivity >>> onCreateOptionsMenu
 SimpleActivity <<< onCreateOptionsMenu
 SimpleFragment >>> onCreateOptionsMenu
 SimpleFragment <<< onCreateOptionsMenu
 [...]

值得注意的是，此行为仅发生在API＆gt; 19没有支持库。

用于记录的代码非常简单。 SimpleActivity配置内容视图并将一个SimpleFragment实例添加到FragmentManager（如果尚未添加）：

public class SimpleActivity extends LoggerActivity {

  @Override protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_fragment);
    Fragment f = getFragmentManager().findFragmentById(R.id.fragment_container);

    findViewById(R.id.btn_dialog).setOnClickListener(new View.OnClickListener() {
      @Override public void onClick(View v) {
        startActivity(new Intent(SimpleActivity.this, DialogActivity.class));
      }
    });

    findViewById(R.id.btn_activity).setOnClickListener(new View.OnClickListener() {
      @Override public void onClick(View v) {
        startActivityForResult(new Intent(SimpleActivity.this, ResultActivity.class), Utils.REQUEST_CODE);
      }
    });

    if (f == null) {
      getFragmentManager()
        .beginTransaction()
        .replace(R.id.fragment_container, new SimpleFragment())
        .commit();
    }
  }
}

//////

public class SimpleFragment extends LoggerFragment {
  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    setHasOptionsMenu(true);
    super.onCreateView(inflater, container, savedInstanceState);
    View v = inflater.inflate(R.layout.fragment_layout, container, false);
    TextView txt = (TextView) v.findViewById(R.id.fragment_text);
    txt.setText(this instanceof CustomName ? ((CustomName) this).getCustomName() : getClass().getSimpleName());
    return v;
  }
}

LoggerActivity和LoggerFragment实现所有生命周期方法，并在每个方法上调用Utils.logBeforeSuper和Utils.logAfterSuper。

public class LoggerActivity extends Activity {

  /* [...] */

  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    Utils.logBeforeSuper(this);
    boolean b = super.onCreateOptionsMenu(menu);
    Utils.logAfterSuper(this);
    return b;
  }

  /* [...] */

}

public class LoggerFragment extends Fragment {
  /* [...] */

  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    Utils.logBeforeSuper(this);
    View v = super.onCreateView(inflater, container, savedInstanceState);
    Utils.logAfterSuper(this);
    return v;
  }

  /* [...] */
}

所以，我想知道预期的行为是什么？我错过了什么或没有记录吗？

一些链接

可以在此处找到完整的日志文件 （方向更改流程从第108行开始） ：https://docs.google.com/spreadsheets/d/1u97W9QZIEDcJt1Q2xh5VQP4YliHjzHE0u2OlLF4y5WY/edit#gid=0

该项目托管在github上:(我没有足够的声誉来添加更多链接）

Whole Project: https://github.com/TartagliaEG/android-lifecycle-tests    
LoggerActivity: /app/src/main/java/com/lifecycletests/base/loggers/LoggerActivity.java    
LoggerFragment: /app/src/main/java/com/lifecycletests/base/loggers/LoggerFragment.java    
Utils: /app/src/main/java/com/lifecycletests/utils/Utils.java    
SimpleActivity: /app/src/main/java/com/lifecycletests/simple/SimpleActivity.java    
SimpleFragment: /app/src/main/java/com/lifecycletests/simple/SimpleFragment.java

当方向发生变化时，Android onCreateOptionsMenu会调用两次

0 个答案: