打开硬件菜单按钮上的操作栏中的子菜单单击

Question

标题解释了所有内容。我想打开操作栏中的子菜单时点击硬件菜单按钮

这是代码，它工作正常，我第一次点击菜单。每个其他时间，它只是闪烁（打开，立即关闭它）

private Menu mainMenu; 
public boolean onCreateOptionsMenu(Menu menu) { 

MenuInflater inflater = getMenuInflater(); 
inflater.inflate(R.menu.options, menu); 
mainMenu = menu; 

return true; 
} 

public boolean onKeyDown(int keyCode, KeyEvent event) { 
if(event.getAction() == KeyEvent.ACTION_DOWN){ 
    switch(keyCode) { 
    case KeyEvent.KEYCODE_MENU: 

     mainMenu.performIdentifierAction(R.id.more, 0); 

     return true; 
    } 
} 
return super.onKeyDown(keyCode, event); 
} 

，这里是options.xml

<?xml version="1.0" encoding="utf-8"?> 
<menu xmlns:android="http://schemas.android.com/apk/res/android" > 

<item 
    android:id="@+id/settings" 
    android:icon="@drawable/ic_menu_preferences" 
    android:showAsAction="ifRoom|withText" 
    android:title="Settings"/> 

<item 
    android:id="@+id/about" 
    android:icon="@drawable/ic_menu_info_details" 
    android:showAsAction="ifRoom|withText" 
    android:title="About"/> 

<item 
    android:id="@+id/more" 
    android:icon="@drawable/ic_menu_moreoverflow_normal_holo_dark" 
    android:showAsAction="always|withText" 
    android:title="More"> 
    <menu> 
     <item 
    android:id="@+id/changelog" 
    android:icon="@drawable/ic_menu_recent_history" 
    android:showAsAction="ifRoom|withText" 
    android:title="Changelog"/> 
     <item 
    android:id="@+id/update" 
    android:icon="@drawable/ic_menu_refresh" 
    android:showAsAction="ifRoom|withText" 
    android:title="Update Check"/> 
<item 
    android:id="@+id/check" 
    android:icon="@drawable/ic_menu_help" 
    android:showAsAction="ifRoom|withText" 
    android:title="Compatibility Check"/> 
     </menu> 
     </item> 

</menu> 

UPDATE（解决方案） 刚换的onkeydown（）方法的onkeyup （），现在它坚持

Answer 1

试试这个：

public boolean onCreateOptionsMenu(Menu menu) 
{ 
    super.onCreateOptionsMenu(menu);// <--- add this 

    MenuInflater inflater = getMenuInflater(); 
    inflater.inflate(R.menu.options, menu); 
    mainMenu = menu; 
    return true; 
} 

//override this method instead of onKeyDown().... 
@Override 
public boolean onOptionsItemSelected(MenuItem item) 
{ 
    super.onOptionsItemSelected(item);  

    int menuId = item.getItemId();  
    if(menuId == R.id.settings) 
    { 
     //do settings 
    } 
    //else if(menuId = ...) {....} 

    return true; 
}