大家都知道,任务程序离不开菜单,菜单无处不在,哪我们一定要学好ANDROID中的菜单,它给我带来了不少的功能。相信大家都知道的。好,现在我们开始吧,下面的代码很简单。看图:
package com.smart; import android.app.Activity; import android.os.Bundle; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.Button; public class SmartMenu extends Activity { public static final int ITEM0=Menu.FIRST;//系统值 public static final int ITEM1=Menu.FIRST+1; public static final int ITEM2=Menu.FIRST+2; public static final int ITEM3=Menu.FIRST+3; Button button1; Button button2; Button button3; Button button4; // private Menu menu; // private Menu menu /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); button1=(Button)findViewById(R.id.button1); button2=(Button)findViewById(R.id.button2); button3=(Button)findViewById(R.id.button3); button4=(Button)findViewById(R.id.button4); button1.setVisibility(View.INVISIBLE); button2.setVisibility(View.INVISIBLE); button3.setVisibility(View.INVISIBLE); button4.setVisibility(View.INVISIBLE); // } @Override public boolean onCreateOptionsMenu(Menu menu) { super.onCreateOptionsMenu(menu); menu.add(0, ITEM0, 0,"显示button1"); menu.add(0, ITEM1,0,"显示button2"); menu.add(0, ITEM2,0,"新建"); menu.add(0, ITEM3,0,"打开"); menu.findItem(ITEM1);//可以设置按钮的背景 return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case ITEM0: actionClickMenuItem1(); break; case ITEM1: actionClickMenuItem2(); break; case ITEM2: actionClickMenuItem3(); break; case ITEM3: actionClickMenuItem4(); break; } return super.onOptionsItemSelected(item); } //第一个事件的方法 private void actionClickMenuItem1(){ setTitle("button1可见"); button1.setVisibility(View.VISIBLE);//可见 button2.setVisibility(View.INVISIBLE);//不可见 } //第2个事件的方法 private void actionClickMenuItem2(){ setTitle("button2可见"); button1.setVisibility(View.INVISIBLE);//不可见 button2.setVisibility(View.VISIBLE);//可见 } private void actionClickMenuItem3(){ setTitle("button2可见"); button1.setVisibility(View.INVISIBLE);//不可见 button2.setVisibility(View.INVISIBLE);//不可见 button3.setVisibility(View.VISIBLE);//可见 button4.setVisibility(View.INVISIBLE);//不可见 } private void actionClickMenuItem4(){ setTitle("button2可见"); button1.setVisibility(View.INVISIBLE);//不可见 button2.setVisibility(View.INVISIBLE);//不可见 button3.setVisibility(View.INVISIBLE);//不可见 button4.setVisibility(View.VISIBLE);//可见 } }
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="wrap_content" > <Button android:id="@+id/button1" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="我的菜单我做主_1" /> <Button android:id="@+id/button2" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="我的菜单我做主_2" /> <Button android:id="@+id/button3" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="小子,给记住这代码" /> <Button android:id="@+id/button4" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="哈哈,你欺负我呀,我就能记住" /> </LinearLayout>