TabHost与RadioGroup结合完成的菜单

TabHost与RadioGroup结合完成的菜单,记录下
转自:http://www.iteye.com/topic/1116261

效果图:

首先看布局文件：

<?xml version="1.0" encoding="UTF-8"?><TabHost android:id="@android:id/tabhost" android:layout_width="fill_parent" android:layout_height="fill_parent"  xmlns:android="http://schemas.android.com/apk/res/android">    <LinearLayout     android:orientation="vertical"     android:layout_width="fill_parent"     android:layout_height="fill_parent">        <FrameLayout         android:id="@android:id/tabcontent"         android:layout_width="fill_parent"         android:layout_height="0.0dip"         android:layout_weight="1.0" />        <TabWidget         android:id="@android:id/tabs"         android:visibility="gone"         android:layout_width="fill_parent"         android:layout_height="wrap_content"         android:layout_weight="0.0" />        <RadioGroup         android:gravity="center_vertical"         android:layout_gravity="bottom"         android:orientation="horizontal"         android:id="@+id/main_radio"         android:background="@drawable/maintab_toolbar_bg"         android:layout_width="fill_parent"         android:layout_height="wrap_content">            <RadioButton             android:id="@+id/radio_button0"             android:tag="radio_button0"             android:layout_marginTop="2.0dip"             android:text="@string/alarm"             android:drawableTop="@drawable/icon_1"             style="@style/main_tab_bottom" />            <RadioButton             android:id="@+id/radio_button1"             android:tag="radio_button1"             android:layout_marginTop="2.0dip"             android:text="@string/message"             android:drawableTop="@drawable/icon_2"             style="@style/main_tab_bottom" />            <RadioButton             android:id="@+id/radio_button2"             android:tag="radio_button2"             android:layout_marginTop="2.0dip"             android:text="@string/photo"             android:drawableTop="@drawable/icon_3"             style="@style/main_tab_bottom" />            <RadioButton             android:id="@+id/radio_button3"             android:tag="radio_button3"             android:layout_marginTop="2.0dip"             android:text="@string/music"             android:drawableTop="@drawable/icon_4"             style="@style/main_tab_bottom" />            <RadioButton             android:id="@+id/radio_button4"             android:tag="radio_button4"             android:layout_marginTop="2.0dip"             android:text="@string/setting"             android:drawableTop="@drawable/icon_5"             style="@style/main_tab_bottom" />        </RadioGroup>    </LinearLayout></TabHost>

需要注意的是，如果用TabHost这个控件，其中有几个ID是必须这么写的，android:id="@android:id/tabhost ；android:id="@android:id/tabcontent" ；android:id="@android:id/tabs" ；之所以要这么写是因为在TabHost这个类中。需要实例化上述这个ID的控件。看源码：

在TabActivity中有么个方法：

@Overridepublic void onContentChanged() {super.onContentChanged();mTabHost = (TabHost) findViewById(com.android.internal.R.id.tabhost);if (mTabHost == null) {throw new RuntimeException("Your content must have a TabHost whose id attribute is " +"'android.R.id.tabhost'");}mTabHost.setup(getLocalActivityManager());}private void ensureTabHost() {if (mTabHost == null) {this.setContentView(com.android.internal.R.layout.tab_content);}}

当内容发生改变时它会调用这个方法，来更新列表或者其他视图，而这个方法中需要实例化TabHost，所以必须通过ID为tabhost实例化。

再看看TabHost这个类中，

public void setup() {mTabWidget = (TabWidget) findViewById(com.android.internal.R.id.tabs);if (mTabWidget == null) {throw new RuntimeException("Your TabHost must have a TabWidget whose id attribute is 'android.R.id.tabs'");}// KeyListener to attach to all tabs. Detects non-navigation keys// and relays them to the tab content.mTabKeyListener = new OnKeyListener() {public boolean onKey(View v, int keyCode, KeyEvent event) {switch (keyCode) {case KeyEvent.KEYCODE_DPAD_CENTER:case KeyEvent.KEYCODE_DPAD_LEFT:case KeyEvent.KEYCODE_DPAD_RIGHT:case KeyEvent.KEYCODE_DPAD_UP:case KeyEvent.KEYCODE_DPAD_DOWN:case KeyEvent.KEYCODE_ENTER:return false;}mTabContent.requestFocus(View.FOCUS_FORWARD);return mTabContent.dispatchKeyEvent(event);}};mTabWidget.setTabSelectionListener(new TabWidget.OnTabSelectionChanged() {public void onTabSelectionChanged(int tabIndex, boolean clicked) {setCurrentTab(tabIndex);if (clicked) {mTabContent.requestFocus(View.FOCUS_FORWARD);}}});mTabContent = (FrameLayout) findViewById(com.android.internal.R.id.tabcontent);if (mTabContent == null) {throw new RuntimeException("Your TabHost must have a FrameLayout whose id attribute is "+ "'android.R.id.tabcontent'");}}

这个方法，是在增加选项卡之前由系统调用。在这个方法中需要通过tabs 这个ID实例化一个TabWidget，通过tabcontent这个ID实例化一个FrameLayout，用来放置选项卡内容。所以这两个ID也是固定的。

在上述布局文件中隐藏了系统默认的Widget，取而代之的是带有图片的Button。

看一下主要代码：

package com.iteye.androidtoast;import android.app.TabActivity;import android.content.Intent;import android.os.Bundle;import android.widget.RadioGroup;import android.widget.RadioGroup.OnCheckedChangeListener;import android.widget.TabHost;public class MainActivity extends TabActivity implements OnCheckedChangeListener{    /** Called when the activity is first created. */private TabHost mHost;private RadioGroup radioderGroup;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.maintabs);        //实例化TabHost        mHost=this.getTabHost();                //添加选项卡        mHost.addTab(mHost.newTabSpec("ONE").setIndicator("ONE")        .setContent(new Intent(this,OneActivity.class)));        mHost.addTab(mHost.newTabSpec("TWO").setIndicator("TWO")        .setContent(new Intent(this,TwoActivity.class)));        mHost.addTab(mHost.newTabSpec("THREE").setIndicator("THREE")        .setContent(new Intent(this,ThreeActivity.class)));        mHost.addTab(mHost.newTabSpec("FOUR").setIndicator("FOUR")        .setContent(new Intent(this,FourActivity.class)));        mHost.addTab(mHost.newTabSpec("FIVE").setIndicator("FIVE")        .setContent(new Intent(this,FiveActivity.class)));                radioderGroup = (RadioGroup) findViewById(R.id.main_radio);radioderGroup.setOnCheckedChangeListener(this);    }@Overridepublic void onCheckedChanged(RadioGroup group, int checkedId) {switch(checkedId){case R.id.radio_button0:mHost.setCurrentTabByTag("ONE");break;case R.id.radio_button1:mHost.setCurrentTabByTag("TWO");break;case R.id.radio_button2:mHost.setCurrentTabByTag("THREE");break;case R.id.radio_button3:mHost.setCurrentTabByTag("FOUR");break;case R.id.radio_button4:mHost.setCurrentTabByTag("FIVE");break;}}}

更多相关文章

随机推荐