保存選項菜單共享首選項

Question

我有一個選項菜單。當活動失去焦點時，選定的選項菜單項保留狀態，但當我的活動被破壞時，所有選項都會重置。

如何從已銷燬狀態恢復後保存所選首選項的狀態？有問題可視化如何實現代碼Shared Preferences。

（只需要布爾值，但我已經包含了靜態菜單項。）

public final static int MENU_SOMETHING_MODE_ON = 1; 
public final static int MENU_SOMETHING_MODE_OFF = 2; 
public final static int MENU_FULLSCREEN_ON = 3; 
public final static int MENU_FULLSCREEN_OFF = 4; 
public final static int MENU_SOUND_ON = 5; 
public final static int MENU_SOUND_OFF = 6; 
public final static int MENU_FASTER = 7; 
public final static int MENU_SLOWER = 8; 
public final static int MENU_SOMETHING = 9; 
public final static int MENU_EXTRAS = 10; 

private static boolean soundOn = true; 
private static boolean mFaster = true; 

private boolean fullscreen = true; 

@Override 
public boolean onCreateOptionsMenu(Menu menu) 
{ 
    super.onCreateOptionsMenu(menu); 
    menu.add(0, MENU_SOMETHING, 0, R.string.menu_new_something); 
    menu.add(0, MENU_SOMETHING_MODE_ON, 0, 
      R.string.menu_something_on); 
    menu.add(0, MENU_SOMETHING_MODE_OFF, 0, 
      R.string.menu_something_off); 
    menu.add(0, MENU_FULLSCREEN_ON, 0, R.string.menu_fullscreen_on); 
    menu.add(0, MENU_FULLSCREEN_OFF, 0, R.string.menu_fullscreen_off); 
    menu.add(0, MENU_SOUND_ON, 0, R.string.menu_sound_on); 
    menu.add(0, MENU_SOUND_OFF, 0, R.string.menu_sound_off); 
    menu.add(0, MENU_FASTER, 0, R.string.menu_faster); 
    menu.add(0, MENU_SLOWER, 0, R.string.menu_slower); 
    menu.add(0, MENU_EXTRAS, 0, R.string.menu_extras); 
    return true; 
} 

@Override 
public boolean onPrepareOptionsMenu(Menu menu) 
{ 
    super.onPrepareOptionsMenu(menu); 
    menu.findItem(MENU_SOUND_ON).setVisible(!getSoundOn()); 
    menu.findItem(MENU_SOUND_OFF).setVisible(getSoundOn()); 
    menu.findItem(MENU_SOMETHING_ON).setVisible(
     getMode() == SOMETHING_NORMAL); 
    menu.findItem(MENU_SOMETHING_OFF).setVisible(
     getMode() != SOMETHING_NORMAL); 
    menu.findItem(MENU_FULLSCREEN_ON).setVisible(!fullscreen); 
    menu.findItem(MENU_FULLSCREEN_OFF).setVisible(fullscreen); 
    menu.findItem(MENU_FASTER).setVisible(getFaster()); 
    menu.findItem(MENU_SLOWER).setVisible(!getFaster()); 
    return true; 
} 


@Override 
public boolean onOptionsItemSelected(MenuItem item) 
{ 
    switch (item.getItemId()) { 
    case MENU_SOMETHING: 

    AlertDialog.Builder alt_bld = new AlertDialog.Builder(this); 

    alt_bld.setMessage("Are you sure?") 
    .setCancelable(false) 
    .setPositiveButton("Yes", new DialogInterface.OnClickListener() { 
      public void onClick(DialogInterface dialog, int id) { 
       // Action for 'YES' Button 
       something.new(); 
      } 
     }) 
    .setNegativeButton("No", new DialogInterface.OnClickListener() { 
      public void onClick(DialogInterface dialog, int id) { 
       // Action for 'NO' Button 
       dialog.cancel(); 
      } 
     }); 
     AlertDialog alert = alt_bld.create(); 
     // Title for AlertDialog 
     alert.setTitle("Something"); 
     // Icon for AlertDialog 
     alert.setIcon(R.drawable.dialog); 
     alert.show(); 


     return true; 
    case MENU_SOMETHING_ON: 
     setMode(THIS_SOMETHING); 
     return true; 
    case MENU_SOMETHING_OFF: 
     setMode(THIS_NORMAL); 
     return true; 
    case MENU_FULLSCREEN_ON: 
     fullscreen = true; 
     setFullscreen(); 
     return true; 
    case MENU_FULLSCREEN_OFF: 
     fullscreen = false; 
     setFullscreen(); 
     return true; 
    case MENU_SOUND_ON: 
     setSoundOn(true); 
     return true; 
    case MENU_SOUND_OFF: 
     setSoundOn(false); 
     return true; 
    case MENU_FASTER: 
     setFaster(false); 
     return true; 
    case MENU_SLOWER: 
     setSlower(true); 
     return true; 
    case MENU_EXTRAS: 
     startExtras(); 
     return true; 
    } 
    return false; 
} 

private void setFullscreen() 
{ 
    if (fullscreen) { 
     getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN); 
     getWindow().clearFlags(
      WindowManager.LayoutParams.FLAG_FORCE_NOT_FULLSCREEN); 
    } else { 
     getWindow().clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN); 
     getWindow().addFlags(
      WindowManager.LayoutParams.FLAG_FORCE_NOT_FULLSCREEN); 
    } 
    mView.requestLayout(); 
} 

public synchronized static void setMode(int newMode) 
{ 
    Mode = newMode; 
} 

public synchronized static int getMode() 
{ 
    return Mode; 
} 

public synchronized static boolean getSoundOn() 
{ 
    return soundOn; 
} 

public synchronized static void setSoundOn(boolean so) 
{ 
    soundOn = so; 
} 

public synchronized static boolean getFaster() 
{ 
    return Faster; 
} 

public synchronized static void setFaster(boolean dont) 
{ 
    Faster = dont; 
} 

Answer 1

This is a fantastic tutorial如何與如何獲取/設置這些首選項一起創建活動的偏好。如果您選擇不執行偏好活動，它還會向您展示如何使用共享偏好設置。

幾乎所有用戶都熟悉偏好活動，因爲他們是如何調整手機設置的。

雖然不是實現「選項」的唯一方法，或者可能甚至可能不是最佳方式，但它很好，具有很大的靈活性，並且實施起來簡單快捷。