如何使用Android偏好创建一次性欢迎屏幕？

Question

我想创建一个屏幕，在应用程序启动后仅显示一次。之后，它只会显示主屏幕。我实现这个的方式只是检查首选项，并根据标志设置当前布局。以这种方式实施它有什么缺点吗？有没有更好的办法？

@Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     //Here is the main layout 
     setContentView(R.layout.main);  

     mPrefs = PreferenceManager.getDefaultSharedPreferences(this); 

     // second argument is the default to use if the preference can't be found 
     Boolean welcomeScreenShown = mPrefs.getBoolean(welcomeScreenShownPref, false); 

     if (!welcomeScreenShown) { 
      //Here I set the one-time layout 
      setContentView(R.layout.popup_message);    
      SharedPreferences.Editor editor = mPrefs.edit(); 
      editor.putBoolean(welcomeScreenShownPref, true); 
      editor.commit(); // Very important to save the preference 
     } 
    } 

Answer 1

尝试用应用版本代码。以下是我使用的示例代码;

SharedPreferences sharedPreferences = getSharedPreferences("version", 0); 
    int savedVersionCode = sharedPreferences.getInt("VersionCode", 0); 

    int appVershionCode = 0; 

    try { 
     appVershionCode = getPackageManager().getPackageInfo(getPackageName(), 0).versionCode; 

    } catch (NameNotFoundException nnfe) { 
     Log.w(TAG, "$ Exception caz of appVershionCode : " + nnfe); 
    } 

    if(savedVersionCode == appVershionCode){ 
     Log.d(TAG, "$$ savedVersionCode == appVershionCode"); 
    }else{ 
     Log.d(TAG, "$$ savedVersionCode != appVershionCode"); 

     SharedPreferences.Editor sharedPreferencesEditor = sharedPreferences.edit(); 
     sharedPreferencesEditor.putInt("VersionCode", appVershionCode); 
     sharedPreferencesEditor.commit(); 

     Builder alertDialogBuilder = new Builder(this); 
     alertDialogBuilder.setTitle("Version"); 
     alertDialogBuilder.setMessage("This is one time show dialog box "); 

     alertDialogBuilder.setNeutralButton("Close", new OnClickListener() { 

      @Override 
      public void onClick(DialogInterface dialog, int which) { 
       Log.d(TAG, "$$ onClick"); 

      } 
     }); 

     alertDialogBuilder.show(); 
    } 

Answer 2

而不是共享的喜好，你可以使用下面的代码还我已经使用过很多次会很好地工作，仅显示一个时候，应用程序启动第一次

public class SplashActivity extends Activity { 
protected boolean _isActive = true; 
protected int _splashTime = 3000; //SplashActivity will be visible for 2s 
final String TAG = "SplashActivity"; 


public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.splash_activity); 



    //a separate thread to manage splash screen 
    final Thread splashThread = new Thread() { 

     public void run() { 

      try { 
       int wait = 0; 

       while (_isActive && (_splashTime > wait)) { //will show only on the first time 
        sleep(100); 

        if (_isActive) { 
         wait += 100; 
        } 
       } 
      } catch (InterruptedException e) { 
       Log.d(TAG, e.getMessage()); 

      } finally { 
       startActivity(new Intent(SplashActivity.this, MainActivityAbs.class)); 
       finish(); 
      } 
     } 
    }; 
    splashThread.start(); 
} 

//if a user clicks on a back btnOrder, do not show splash screen 

public boolean onTouchEvent(MotionEvent event) { 
    if (event.getAction() == MotionEvent.ACTION_DOWN) { 
     _isActive = false; 
    } 
    return true; 
}