如何通过按下软键在软键盘中打开上下文菜单？

Question

例如，当我在虚拟键盘中选择“完成”软键时，它应该触发上下文菜单以显示诸如
“选项 1”、
“选项 2”、
等选项“选项 3”
标题为“选项”。

以下是我的 xml 文件的简化版本。

<Keyboard xmlns:android="http://schemas.android.com/apk/res/android"
android:keyWidth="10%p"
android:horizontalGap="0px"
android:verticalGap="0px"
android:keyHeight="@dimen/key_height"
>

<Row>
    <Key android:codes="1" android:keyLabel="Encrypt" android:keyEdgeFlags="left"/>
    <Key android:codes="2" android:keyLabel="Translate"/>
    <Key android:codes="3" android:keyLabel="Done" android:keyEdgeFlags="right"/>
</Row>
</Keyboard>

Answer 1

要显示上下文菜单，请参见以下代码：

在Activity的onCreate方法中：

  key.setOnClickListener(new OnClickListener() {  

       @Override  
       public void onClick(View v) {  
        //Creating the instance of PopupMenu  
        PopupMenu popup = new PopupMenu(MainActivity.this, button1);  
        //Inflating the Popup using xml file  
        popup.getMenuInflater().inflate(R.menu.popup_menu, popup.getMenu());  

        //registering popup with OnMenuItemClickListener  
        popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {  
         public boolean onMenuItemClick(MenuItem item) {  
          Toast.makeText(MainActivity.this,"You Clicked : " + item.getTitle(),Toast.LENGTH_SHORT).show();  
          return true;  
         }  
        });  

        popup.show();//showing popup menu
       }  
      });//closing the setOnClickListener method

文件：poupup_menu.xml

<menu xmlns:androclass="http://schemas.android.com/apk/res/android" >  

<item  
    android:id="@+id/one"  
    android:title="One"/>  

<item  
    android:id="@+id/two"  
    android:title="Two"/>  

<item  
    android:id="@+id/three"  
    android:title="Three"/>  

</menu>

Answer 2

您的软键盘按键在扩展 InputMethodService 并实现 onKeyboardActionListener 的服务中处理。

在服务中，您正在处理软键盘上的按键，添加弹出菜单代码，否则您将在应用程序中使用屏幕按钮。 像这样：

public class MyKeyboardService extends InputMethodService implements KeyboardView.OnKeyboardActionListener
{
    private KeyboardView viewOfKeyboard;
    private Keyboard theKeyboardLayout;

    @Override
    public View onCreateInputView()
    {
        viewOfKeyboard = (KeyboardView)getLayoutInflater().inflate(R.layout.keyboard1, null);
        theKeyboardLayout = new Keyboard(this, R.xml.keyboardlayout);
        viewOfKeyboard.setKeyboard(theKeyboardLayout);
        viewOfKeyboard.setOnKeyboardActionListener(this);
        return viewOfKeyboard;
    }


    .................//InputMethodService methods goes here

    @Override
    public void onKey(int primaryCode, int[] keyCodes)
    {
        InputConnection ic = getCurrentInputConnection();

        switch(primaryCode){ 
        case -222: //-222 is just a random ID number I assigned my key on the softkeyboard.
            PopupMenu popup = new PopupMenu(MyKeyboardService.this, viewOfKeyboard);
            popup.getMenuInflater().inflate(R.menu.menu_main, popup.getMenu());
            //menu_main being the xml file for the popup menu
            popup.show();
            break;
    }
}

从那里，只需像往常一样添加代码来处理弹出菜单中的按钮点击。

menu_main XML 文件供参考：

< menu xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      xmlns:tools="http://schemas.android.com/tools"
      tools:context=".MainActivity">
      < item android:id="@+id/action_settings"
          android:title="@string/action_settings"
          android:orderInCategory="100"
          app:showAsAction="never"/>
      < item android:id="@+id/button1"
              android:title="button1"/>
< /menu>