android studio tabhost基础 多功能时钟app tabhost

新建项目，在layout中添加tabhost组件：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:tools="http://schemas.android.com/tools"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:paddingBottom="@dimen/activity_vertical_margin"  android:paddingLeft="@dimen/activity_horizontal_margin"  android:paddingRight="@dimen/activity_horizontal_margin"  android:paddingTop="@dimen/activity_vertical_margin"  android:orientation="vertical"  tools:context="com.example.jowang.clock.MainActivity"><TabHost  android:layout_width="match_parent"  android:layout_height="wrap_content"  android:id="@+id/tabHost"  android:layout_gravity="center_horizontal"><LinearLayout  android:layout_width="match_parent"  android:layout_height="match_parent"  android:orientation="vertical"><TabWidget  android:id="@android:id/tabs"  android:layout_width="match_parent"  android:layout_height="wrap_content"></TabWidget><FrameLayout  android:id="@android:id/tabcontent"  android:layout_width="match_parent"  android:layout_height="match_parent"><LinearLayout  android:id="@+id/tabTime"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:orientation="vertical"></LinearLayout><LinearLayout  android:id="@+id/tabAlarm"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:orientation="vertical"></LinearLayout><LinearLayout  android:id="@+id/tabTimer"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:orientation="vertical"></LinearLayout><LinearLayout  android:id="@+id/tabStopwatch"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:orientation="vertical"></LinearLayout></FrameLayout></LinearLayout></TabHost>
</LinearLayout>

public class MainActivity extends AppCompatActivity {private TabHost tabHost;@Override
    protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);tabHost=(TabHost)findViewById(R.id.tabHost);tabHost.setup();tabHost.addTab(tabHost.newTabSpec("tabTime").setIndicator("时钟").setContent(R.id.tabTime));tabHost.addTab(tabHost.newTabSpec("tabAlarm").setIndicator("闹钟").setContent(R.id.tabAlarm));tabHost.addTab(tabHost.newTabSpec("tabTimer").setIndicator("计时器").setContent(R.id.tabTimer));tabHost.addTab(tabHost.newTabSpec("tabStopwatch").setIndicator("秒表").setContent(R.id.tabStopwatch));}
}