從上下文菜單切換到正確的活動

Question

我的問題是如何從上下文菜單切換到正確的活動。

我有這樣的活動：

• Main
• AccelerometerOptionsActivity
• GyroscopeOptionsActivity
• OrientationOptionsActivity

在主要活動中我有傳感器的列表。當我點擊傳感器時，會出現上下文菜單，我可以點擊例如選項。

我的問題是如何從上下文菜單切換到所選傳感器的選項活動。 我的代碼：

@Override 
    public boolean onContextItemSelected(MenuItem item) { 
     AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo)item.getMenuInfo(); 
     int menuItemIndex = item.getItemId(); 
     String[] menuItems = getResources().getStringArray(R.array.sensor_array); 
     String menuItemName = menuItems[menuItemIndex]; 


     if(item.getTitle()=="Start Service"){ 
      Toast.makeText(this,"Start " + menuItemName+ " selected", Toast.LENGTH_SHORT).show(); 
     } else if(item.getTitle()=="Stop Service") { 
      Toast.makeText(this,"Stop " + menuItemName+ " selected", Toast.LENGTH_SHORT).show(); 
     } else if(item.getTitle()=="Options") { 


       Intent options = new Intent(this, AccelerometerOptionsActivity.class); 
       startActivity(options); 

     } 

     return true; 
    } 

UPDATE：

下面是代碼：

@Override 
    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) { 
     if (v.getId()==R.id.list) { 
      AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo)menuInfo; 

      menu.setHeaderTitle(sensorsArray[info.position]); 
      menu.add(Menu.NONE, CONTEXTMENU_START, 0, "Start Service"); 
      menu.add(Menu.NONE, CONTEXTMENU_STOP, 1, "Stop Service"); 
      menu.add(Menu.NONE, CONTEXTMENU_OPTIONS, 2, "Options"); 
      menu.add(Menu.NONE, CONTEXTMENU_GRAPHS, 3, "Graph view"); 
      menu.add(Menu.NONE, CONTEXTMENU_DATA, 4, "Data view"); 
     } 
    } 

Answer 1

在onContextItemSelected()試試這個：

@Override 
    public boolean onContextItemSelected(MenuItem item) { 
     AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) item 
        .getMenuInfo(); 
     int menuItemIndex = item.getItemId(); // the position of the item in the list with the context menu 
     String[] menuItems = getResources().getStringArray(R.array.sensor_array); 
     String menuItemName = menuItems[menuItemIndex]; 
     switch (item.getItemId()) { 
     case CONTEXTMENU_START: 
      Toast.makeText(this, "Start " + menuItemName + " selected", 
         Toast.LENGTH_SHORT).show(); 
     break; 
     case CONTEXTMENU_STOP: 
      Toast.makeText(this, "Stop " + menuItemName + " selected", 
        Toast.LENGTH_SHORT).show(); 
     break; 
      case CONTEXTMENU_OPTIONS: 
     // here start the correct options activity either by checking for 
     // String equality with menuItemName or by doing a switch on the menuItemIndex(this works 
     // if your list of sensors is based on the array R.array.sensor_array) 
      switch (menuItemIndex) { 
       case 0: 
       //the user clicked the first sensor in the list so start that option activity   
       break; 
       case 1: 
       //the user clicked the second sensor in the list so start that option activity 
        break; 
       } 
     } 
     return super.onContextItemSelected(item); 
} 

Answer 2

使用。載有（yourString）方法，而不是==。 例如更換

if(item.getTitle()=="Options") {... 

與

if(item.getTitle().contains("Options") {...