我可以禁止在特定邏輯的BottomNavigationView項目中移動嗎？

Question

目前我有像這個 -

mBottomNav.setOnNavigationItemSelectedListener(
       ...... 
    switch (item.getItemId()) { 

     case R.id.actionUser: 
      if(userLoggedIn) { 
       mHomePresenter.btnUser(); 
      } 
      else { 
       showLongToast("User Not Logged In"); 
      } 
      break; 
    }); 

邏輯其他部分的實現，我將顯示敬酒消息，無論是我想要的BottomNavigationView轉移也沒有菜單圖標的顏色變化。

如何才能在這個特定的部分實現這樣的邏輯？所有其他菜單項將保持默認的切換邏輯。

Answer 1

那麼答案很簡單，對於條件你要過渡到發生，因爲你不想返回false

以你的代碼考慮條件返回true，它應該是

mBottomNav.setOnNavigationItemSelectedListener(
    @Override 
    public boolean onNavigationItemSelected(@NonNull MenuItem item) { 
     switch (item.getItemId()) { 
     case R.id.actionUser: 
      if(userLoggedIn) { 
       mHomePresenter.btnUser(); 
       return true; 
      } 
      else { 
       showLongToast("User Not Logged In"); 
       return false; 
      } 
     } 
    }); 

如果檢查導航選擇監聽器的文件，你可以看到

/** 
* Listener for handling selection events on bottom navigation items. 
*/ 
public interface OnNavigationItemSelectedListener { 

    /** 
    * Called when an item in the bottom navigation menu is selected. 
    * 
    * @param item The selected item 
    * 
    * @return true to display the item as the selected item and false if the item should not 
    *   be selected. Consider setting non-selectable items as disabled preemptively to 
    *   make them appear non-interactive. 
    */ 
    boolean onNavigationItemSelected(@NonNull MenuItem item); 
}