如何調用方法finished（）以退出整個PreferenceActivity

我使用官方的SettingsActivity作爲我的活動的模板，並且我的偏好活動有兩個靜態類「preferencefragment1」和「preferencefragment2」。如何調用方法finished（）以退出整個PreferenceActivity

當應用程序單擊preferenceactivity的標題時，它切換到指定的preferencefragment。然後用KEYCODE_BACK事件調用onkeydown（）方法中的finished（）方法。它將返回到標題視圖。但是，我想要的是它從preferencefragment視圖返回到mainactivity，使整個PreferenceActivity完成而不僅僅是preferencefragment1視圖。

因爲我想使用preferenceActivity來設置藍牙通信設備的參數，並且在參數完成設置後，它可以立即將參數發送到onActivityResult（）方法中的設備。但現在，我必須兩次單擊BACK按鈕才能返回主活動。是否可以跳過標題視圖直接顯示或直接跳入preference片段視圖？ program flow

import android.annotation.TargetApi; 
import android.app.AlertDialog; 
import android.content.Context; 
import android.content.DialogInterface; 
import android.content.Intent; 
import android.content.res.Configuration; 
import android.os.Build; 
import android.os.Bundle; 
import android.preference.EditTextPreference; 
import android.preference.ListPreference; 
import android.preference.Preference; 
import android.preference.PreferenceActivity; 
import android.app.ActionBar; 
import android.preference.PreferenceFragment; 
import android.preference.PreferenceManager; 
import android.preference.SwitchPreference; 
import android.util.Log; 
import android.view.KeyEvent; 
import android.view.MenuItem; 
import java.util.List; 
public class SettingsActivity extends PreferenceActivity { 
    private static List<Header> headers; 
    private static Preference.OnPreferenceChangeListener sBindPreferenceSummaryToValueListener = new Preference.OnPreferenceChangeListener() { 
     @Override 
     public boolean onPreferenceChange(Preference preference, Object value) { 
      String stringValue = value.toString(); 
      if (preference instanceof ListPreference) { 
       ListPreference listPreference = (ListPreference) preference; 
       int index = listPreference.findIndexOfValue(stringValue); 
       preference.setSummary(
         index >= 0 
           ? listPreference.getEntries()[index] 
           : null); 
      } 
      if (preference instanceof EditTextPreference) { 
       EditTextPreference editTextPreference = (EditTextPreference) preference; 
       editTextPreference.setSummary(stringValue); 
      } 
      if (preference instanceof SwitchPreference) { 
       SwitchPreference switchPreference = (SwitchPreference) preference; 
       switchPreference.setSummary(stringValue); 
      } 
      return true; 
     } 
    }; 

    private static boolean isXLargeTablet(Context context) { 
     return (context.getResources().getConfiguration().screenLayout 
       & Configuration.SCREENLAYOUT_SIZE_MASK) >= Configuration.SCREENLAYOUT_SIZE_XLARGE; 
    } 
    public boolean onKeyDown(int keyCode, KeyEvent event) { 
     if (keyCode == KeyEvent.KEYCODE_BACK) { 
      AlertDialog.Builder builder = new AlertDialog.Builder(this); 
      builder.setTitle("Confirm to update system paras?"); 
      builder.setPositiveButton("YES", new DialogInterface.OnClickListener() { 
       @Override 
       public void onClick(DialogInterface dialog, int which) { 
        setResult(RESULT_OK); 
        finish(); 

       } 
      }); 
      builder.setNegativeButton("CANCELED", new DialogInterface.OnClickListener() { 
       @Override 
       public void onClick(DialogInterface dialog, int which) { 
        finish(); 
       } 
      }); 
      builder.show(); 
     } 
     return super.onKeyDown(keyCode, event); 
    } 
    @Override 
    protected void onActivityResult (int requestCode, int resultCode, Intent data) 
    { 
     System.out.print(resultCode); 
    } 

    private static void bindPreferenceSummaryToValue(Preference preference) { 
     // Set the listener to watch for value changes. 
     preference.setOnPreferenceChangeListener(sBindPreferenceSummaryToValueListener); 
     // Trigger the listener immediately with the preference's 
     // current value. 
     sBindPreferenceSummaryToValueListener.onPreferenceChange(preference, 
       PreferenceManager 
         .getDefaultSharedPreferences(preference.getContext()) 
         .getString(preference.getKey(), "")); 
    } 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     // addPreferencesFromResource(R.xml.pref_system); 
     setupActionBar(); 
    } 

    private void setupActionBar() { 
     ActionBar actionBar = getActionBar(); 
     if (actionBar != null) { 
      // Show the Up button in the action bar. 
      // actionBar.setDisplayHomeAsUpEnabled(true); 
     } 
    } 

    /** 
    * {@inheritDoc} 
    */ 
    @Override 
    public boolean onIsMultiPane() { 
     return isXLargeTablet(this); 
    } 

    /** 
    * {@inheritDoc} 
    */ 
    @Override 
    @TargetApi(Build.VERSION_CODES.HONEYCOMB) 
    public void onBuildHeaders(List<Header> target) { 
     loadHeadersFromResource(R.xml.pref_headers, target); 
     headers=target; 
    } 

    /** 
    * This method stops fragment injection in malicious applications. 
    * Make sure to deny any unknown fragments here. 
    */ 
    protected boolean isValidFragment(String fragmentName) { 
     return PreferenceFragment.class.getName().equals(fragmentName) 
       || SystemPreferenceFragment.class.getName().equals(fragmentName); 

    } 

    /** 
    * This fragment shows general preferences only. It is used when the 
    * activity is showing a two-pane settings UI. 
    */ 
    public static class SystemPreferenceFragment extends PreferenceFragment { 
     @Override 
     public void onCreate(Bundle savedInstanceState) { 
      super.onCreate(savedInstanceState); 
      addPreferencesFromResource(R.xml.pref_system); 
      setHasOptionsMenu(true); 
      bindPreferenceSummaryToValue(findPreference("pref_key_ip")); 
      bindPreferenceSummaryToValue(findPreference("pref_key_port")); 
      bindPreferenceSummaryToValue(findPreference("pref_key_output1_level")); 
      bindPreferenceSummaryToValue(findPreference("pref_key_output2_level")); 
      bindPreferenceSummaryToValue(findPreference("pref_key_output3_level")); 
      bindPreferenceSummaryToValue(findPreference("pref_key_noportrait")); 
      bindPreferenceSummaryToValue(findPreference("pref_key_closeeye")); 
      bindPreferenceSummaryToValue(findPreference("pref_key_yawn")); 
      bindPreferenceSummaryToValue(findPreference("pref_key_distract")); 
     } 

     @Override 
     public boolean onOptionsItemSelected(MenuItem item) { 
      int id = item.getItemId(); 
      if (id == android.R.id.home) { 
       startActivity(new Intent(getActivity(), SettingsActivity.class)); 
       return true; 
      } 
      return super.onOptionsItemSelected(item); 
     } 
    } 

     /* 
     @Override 
     public void onStop() 
     { 
      super.onStop(); 
      AlertDialog.Builder builder = new AlertDialog.Builder(this.getActivity()); 
      builder.setTitle("Confirm to update system paras?"); 
      builder.setPositiveButton("YES", new DialogInterface.OnClickListener() { 
       @Override 
       public void onClick(DialogInterface dialog, int which) { 
        SystemPreferenceFragment.this.getActivity().setResult(RESULT_OK); 
       } 
      }); 
      builder.setNegativeButton("CANCELED", new DialogInterface.OnClickListener() { 
       @Override 
       public void onClick(DialogInterface dialog, int which) { 
        SystemPreferenceFragment.this.getActivity().setResult(RESULT_CANCELED); 
       } 
      }); 
      builder.show(); 
      this.getActivity().finish(); 
     }*/ 

    @TargetApi(Build.VERSION_CODES.HONEYCOMB) 
    public static class RealtimePreferenceFragment extends PreferenceFragment { 
     public void onCreate(Bundle savedInstanceState) { 
      super.onCreate(savedInstanceState); 
      addPreferencesFromResource(R.xml.pref_realtime); 
      setHasOptionsMenu(true); 
     } 

     @Override 
     public boolean onOptionsItemSelected(MenuItem item) { 
      int id = item.getItemId(); 
      if (id == android.R.id.home) { 
       startActivity(new Intent(getActivity(), SettingsActivity.class)); 
       return true; 
      } 
      return super.onOptionsItemSelected(item); 
     } 
    } 
}

來源

2016-11-23 SNOWA

使用getActivity().finish();完成活動

或

使用接口從片段至活動通知背面被按壓

來源

2016-11-23 08:07:47 SaravInfern

我猜它有兩個活動，顯示標題的PreferenceActivity A和顯示設置頁面的PreferenceActivity B. A開始B，而不是preferenceActivity A切換到首選項B片段 – SNOWA

我不瞭解流程可以提供活動流程圖 – SaravInfern

對，我已添加流程圖https://i.stack.imgur.com/ZnHe3巴紐 – SNOWA

問題解決了暴露的方法!!

第1步：在MainActivity中，向Intent添加標誌「FLAG_ACTIVITY_NO_HISTORY」，然後啓動SettingsActivity。

第2步：重寫SettingsActivity（PreferenceActivity）的onBuildStartFragmentIntent（）方法以添加標誌FLAG_ACTIVITY_FORWARD_RESULT，以便activityresult可以返回到MainActivity。

Like below: @Override 

public Intent onBuildStartFragmentIntent (String fragmentName, 
             Bundle args, 
             int titleRes, 
             int shortTitleRes) 
    { 
     Intent intent = new Intent(Intent.ACTION_MAIN); 
     intent.setClass(this, getClass()); 
     intent.putExtra(EXTRA_SHOW_FRAGMENT, fragmentName); 
     intent.putExtra(EXTRA_SHOW_FRAGMENT_ARGUMENTS, args); 
     intent.putExtra(EXTRA_SHOW_FRAGMENT_TITLE, titleRes); 
     intent.putExtra(EXTRA_SHOW_FRAGMENT_SHORT_TITLE, shortTitleRes); 
     intent.putExtra(EXTRA_NO_HEADERS, true); 
     intent.addFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);//the new statement 
     return intent; 
    }

來源

2016-11-25 08:50:32 SNOWA

如何調用方法finished（）以退出整個PreferenceActivity

回答

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