Question

我已经将Deitel的“Flag Quiz”（针对程序员的Android ... App Driven ...）扩展到（除其他外）允许用户显示一个小标志以与给定标志进行比较。用户点按SHOW FLAG，然后获取国家/地区列表，点击一个，然后返回并显示（如下所示）。

enter image description here

我遇到的唯一问题是，点击所需的国家/地区后，会显示Settings首选项屏幕（见下文）。我想这是因为SHOW FLAG是其中的一部分，但我希望用户从列表中选择国家后看到的下一件事就是上面的屏幕。 无需查看下面的屏幕，因此肯定没有理由不必按后退按钮 - 如何避免？ < / p>

enter image description here

仅供参考，这里有一个跟踪和相关的代码片段（我认为没有理由显示任何xml）：

MainActivity.java：

07-06 17:25:48.305  32269-32269/com.dslomer64.flagquiz W/opOptionsItemSelected? item is <Show flag> -----------------------
07-06 17:25:48.350  32269-32269/com.dslomer64.flagquiz W/Here's where? to get flag
07-06 17:25:48.688  32269-32269/com.dslomer64.flagquiz W/onOptionsItemSelected? Show flag showFlag is true
`FlagActivity.java`:
07-06 17:25:48.768  32269-32269/com.dslomer64.flagquiz W/FlagAct? onCreate
07-06 17:25:51.707  32269-32269/com.dslomer64.flagquiz W/returnToA from FlagAct? Anguilla!!!
`SettingsActivity`:
07-06 17:25:51.751  32269-32269/com.dslomer64.flagquiz W/onCreate? SettingsActivity
(not me)
07-06 17:25:51.783  32269-32269/com.dslomer64.flagquiz W/Resources? Converting to string: TypedValue{t=0x10/d=0x3 a=-1}
07-06 17:25:51.786  32269-32269/com.dslomer64.flagquiz W/Resources? Converting to string: TypedValue{t=0x10/d=0x7d0 a=-1}
`MainActivity.java`:
07-06 17:25:55.554  32269-32269/com.dslomer64.flagquiz W/entering? onActivityResult in MainActivity
07-06 17:25:55.569  32269-32269/com.dslomer64.flagquiz W/onActResult? in Main Act show one flag Anguilla
`QuizFragment.java`:
07-06 17:25:55.591  32269-32269/com.dslomer64.flagquiz W/in showAFlag? country: Anguilla

MainActivity.java，这是保留Preferences并选择选项的地方并且处理调用FlagActivity（onActivityResult）的结果：

   @Override public boolean onOptionsItemSelected(MenuItem item){
      Log.w("opOptionsItemSelected", "item is <" + item.getTitle() + "> -----------------------");
      Intent preferencesIntent = new Intent(this, SettingsActivity.class);
      startActivity(preferencesIntent);
      Button getData =  (Button)findViewById(R.id.button2);
      Intent intent = new Intent(
                                  MainActivity.this,
                                  FlagActivity.class
                                 );
      startActivityForResult(intent, 0);

      Log.w("onOptionsItemSelected", "" + item.toString() + " showFlag is " + showFlag);
      return super.onOptionsItemSelected(item); // to SettingsActivity.onCreate
   }

     @Override protected void onActivityResult(int requestCode, int resultCode, Intent data ) {
        Log.w("entering","onActivityResult in MainActivity");
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == 0 && resultCode == Activity.RESULT_OK){
            String enteredData = data.getStringExtra("Data");
            Toast.makeText(getApplicationContext(), "Returned " + enteredData, Toast.LENGTH_SHORT).show();;
            country = enteredData;
            Log.w("onActResult "," in Main Act show one flag " + country);
            quizFragment.showAFlag(country); 
        // ABOVE IS WHERE FLAG IS SHOWN ^^^
        }
    }

FlagActivity.java，这是处理列表视图的地方：

    @Override protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_flag);
    Log.w("FlagAct", " onCreate");
    flagAdapter = new ArrayAdapter<String>(this, R.layout.list_item, flagArray);
    setListAdapter(flagAdapter);
    getListView().setOnItemClickListener(itemClickListener);
}

    AdapterView.OnItemClickListener itemClickListener = new AdapterView.OnItemClickListener() {
    @Override public void onItemClick(AdapterView<?> parent, View view,int position, long id) {
        String country = ((TextView) view).getText().toString();
        Intent result = new Intent();
        result.putExtra("Data", country);
        setResult(Activity.RESULT_OK, result);
        Toast.makeText(getApplicationContext(), country + "!!!", Toast.LENGTH_SHORT).show();
        Log.w("returnToA from FlagAct", country + "!!!");
        finish();
    }
}; // end itemClickListener

。
SettingsActivity.java：

public class SettingsActivity extends Activity // hosts SettingsFragment in portrait mode
{
    @Override protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    Log.w("onCreate", "SettingsActivity");
    setContentView(R.layout.activity_settings);
 }

Answer 1

使用Preference.OnPreferenceChangeListener方法设置setOnPreferenceChangeListener()。

然后，当国家/地区发生变化时，请调用finish()方法退出您的活动

Answer 2

我通过修改onOptionsItemSelected修复了我的问题，但就我如何提问而言，我没有这样做。

  showFlag = (item.toString().equals("Show flag"));

  if(showFlag)                     // If the Settings buttonpress requested a flag,
  {                                // start the activity for it
      Intent intent = new Intent(  
              MainActivity.this,
              FlagActivity.class
              );
      startActivityForResult(intent, 0);
   }                               // but don't start a preferences activity.

   else                            // But if the Settings buttonpress was NOT 'Show flag',
   {                               // start a preferences activity.

      Intent preferencesIntent = new Intent(this, SettingsActivity.class);
      startActivity(preferencesIntent);
   };

我仍然不知道（并且不需要）如何“解雇”Settings屏幕。

但如果可能的话，最好知道如何做到这一点。

如何以编程方式关闭Android设置菜单？

2 个答案: