Android中自定义Menu

在Android中，默认的Menu菜单一行中最多只能显示3个菜单选项，如果我们想在Menu菜单一行中想显示多于3个菜单选项时，我们可以考虑采用PopWindow结合自定义Layout布局文件来创建自定义菜单。

首先，先在布局文件夹layout下面添加一个布局文件，命名为：popup_menu.xml。该文件的代码如下：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="wrap_content" android:layout_height="wrap_content"
  android:orientation="vertical" android:gravity="center_horizontal"
  android:background="@drawable/editbox_background_normal">
    <LinearLayout
       xmlns:android="http://schemas.android.com/apk/res/android"
       android:layout_width="wrap_content" android:layout_height="wrap_content"
       android:orientation="horizontal" android:gravity="center_horizontal">
       
       <LinearLayout
          xmlns:android="http://schemas.android.com/apk/res/android"
          android:layout_width="wrap_content" android:layout_height="wrap_content"
          android:orientation="vertical" android:gravity="center_horizontal"
          android:layout_margin="6dip">
          <Button 
			android:id="@+id/btnClear" android:layout_marginTop="2dip"
			android:layout_width="wrap_content" android:layout_height="wrap_content"
			android:background="@drawable/sms_icon"/>
		 <TextView
		    android:layout_width="wrap_content" android:layout_height="wrap_content"
		    android:text="清除账号" android:textColor="#ff222222"/>
       </LinearLayout>
       
       <LinearLayout
          xmlns:android="http://schemas.android.com/apk/res/android"
          android:layout_width="wrap_content" android:layout_height="wrap_content"
          android:orientation="vertical" android:gravity="center_horizontal"
          android:layout_margin="6dip">
          <Button 
			android:id="@+id/btnSet" android:layout_marginTop="2dip"
			android:layout_width="wrap_content" android:layout_height="wrap_content"
			android:background="@drawable/sms_icon"/>
		 <TextView
		    android:layout_width="wrap_content" android:layout_height="wrap_content"
		    android:text="网络设置" android:textColor="#ff222222"/>
       </LinearLayout>
       
       <LinearLayout
          xmlns:android="http://schemas.android.com/apk/res/android"
          android:layout_width="wrap_content" android:layout_height="wrap_content"
          android:orientation="vertical" android:gravity="center_horizontal"
          android:layout_margin="6dip">
          <Button 
			android:id="@+id/btnHelp" android:layout_marginTop="2dip"
			android:layout_width="wrap_content" android:layout_height="wrap_content"
			android:background="@drawable/sms_icon"/>
		 <TextView
		    android:layout_width="wrap_content" android:layout_height="wrap_content"
		    android:text="帮助更新" android:textColor="#ff222222"/>
       </LinearLayout>
       
       <LinearLayout
          xmlns:android="http://schemas.android.com/apk/res/android"
          android:layout_width="wrap_content" android:layout_height="wrap_content"
          android:orientation="vertical" android:gravity="center_horizontal"
          android:layout_margin="6dip">
          <Button 
			android:id="@+id/btnExit" android:layout_marginTop="2dip"
			android:layout_width="wrap_content" android:layout_height="wrap_content"
			android:background="@drawable/sms_icon"/>
		 <TextView
		    android:layout_width="wrap_content" android:layout_height="wrap_content"
		    android:text="退出程序" android:textColor="#ff222222"/>
       </LinearLayout>
    
    </LinearLayout>
</LinearLayout>

在TestActivity主界面的窗体的代码如下：

public class TestActivity extends Activity {
	
	View view;
	PopupWindow pop;
	Button clearAcc,netSet,helpUpdate,exitApp;
	
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main); 
        
        initPopupWindow();
        setupViews();
    }
 
	/**
	 * 处理键盘事件
	 */
	public boolean onKeyDown(int keyCode, KeyEvent event) {
		if(keyCode == KeyEvent.KEYCODE_MENU){
			if(!pop.isShowing()){
			    pop.showAtLocation(findViewById(R.id.main), Gravity.BOTTOM, 0, 0);
			}else{
				pop.dismiss();
			}
			return true;
		}else{
			return super.onKeyDown(keyCode, event);
		}
	}

	/**
	 * 初始话自定义Menu
	 */
	private void initPopupWindow(){
		view = this.getLayoutInflater().inflate(R.layout.popup_menu, null);
		pop = new PopupWindow(view,ViewGroup.LayoutParams.FILL_PARENT,
				ViewGroup.LayoutParams.WRAP_CONTENT);
		pop.setOutsideTouchable(true);
	}
	
	/**
	 * 控件初始化
	 */
	private void setupViews(){
		clearAcc = (Button)view.findViewById(R.id.btnClear);
		netSet = (Button)view.findViewById(R.id.btnSet);
		helpUpdate = (Button)view.findViewById(R.id.btnHelp);
		exitApp = (Button)view.findViewById(R.id.btnExit);
		
		clearAcc.setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				Toast.makeText(TestActivity.this, "清除账号", Toast.LENGTH_SHORT).show();
			}
		});
		
		netSet.setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				Toast.makeText(TestActivity.this, "网络设置", Toast.LENGTH_SHORT).show();
			}
		});
		
		helpUpdate.setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				Toast.makeText(TestActivity.this, "帮助更新", Toast.LENGTH_SHORT).show();
			}
		});
		
		exitApp.setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				Toast.makeText(TestActivity.this, "退出程序", Toast.LENGTH_SHORT).show();
			}
		});
	}
 
}

当我们运行程序后，点击Menu按钮时显示的自定义菜单如下：