二种方法实现 Android TabWidget

Android TabWidget的实现可以分为二种，一种是使用标准TabActivity实现，另外一种可以自定义方式实现，这种方法实现起来相对比较复杂，但对于要实现比较多元化的view是很好的，这里我们简单看下源码

一、通用做法

继承TabActivity，实现自己的TabActivity

import android.app.Activity;
import android.app.TabActivity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TabHost;
import android.widget.TabHost.OnTabChangeListener;
public class TabWidgetDemo2 extends TabActivity implements OnTabChangeListener {
private TabHost mTabHost;

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);

setContentView(R.layout.tabwidgetdemo2);
mTabHost = getTabHost();
mTabHost.setOnTabChangedListener(this);
setupTab1();
setupTab2();
mTabHost.setCurrentTab(1);
}
private void setupTab2() {
// TODO Auto-generated method stub
Intent intent = new Intent();
intent.setAction(Intent.ACTION_MAIN);
intent.setClass(this, TabWidget2.class);
mTabHost.addTab(mTabHost.newTabSpec("TabWidget2")
.setIndicator("TabWidget2",getResources().getDrawable(R.drawable.icon))
.setContent(intent));
}
private void setupTab1() {
// TODO Auto-generated method stub
Intent intent = new Intent();
intent.setAction(Intent.ACTION_MAIN);
intent.setClass(this, TabWidget1.class);
mTabHost.addTab(mTabHost.newTabSpec("TabWidget1")
.setIndicator("TabWidget1",getResources().getDrawable(R.drawable.icon))
.setContent(intent));
}
public void onTabChanged(String tabId) {
// TODO Auto-generated method stub
Activity activity = getLocalActivityManager().getActivity(tabId);
if (activity != null) {
activity.onWindowFocusChanged(true);
}
}

}

二个tab对应的Activity，先看TabWidget1，这个类在第二种实现中还会用到，因此我们可以看到对Action的判断。

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import com.android.exampledemo.R;
import com.android.exampledemo.util.DemoUtils;
public class TabWidget1 extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);

Intent intent = this.getIntent();
if (intent.getAction().equals(Intent.ACTION_MAIN)){
setContentView(R.layout.tabwidgetdemo2_1);
}
else {
setContentView(R.layout.tabwidget_1);
DemoUtils.updateButtonBar((Activity)this,R.id.contactstab);
}
}
}

再看一下TabWidget2，这个Activity我们在第二种实现方式中也会用到。

import com.android.exampledemo.R;
import com.android.exampledemo.util.DemoUtils;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
public class TabWidget2 extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);

Intent intent = this.getIntent();

if (intent.getAction().equals(Intent.ACTION_MAIN)){
setContentView(R.layout.tabwidgetdemo2_1);
}
else {
setContentView(R.layout.tabwidget_2);
DemoUtils.updateButtonBar((Activity)this,R.id.groupstab);
}
}
}

最后就是各个Activity对应的layout

1.tabwidgetdemo2.xml

<?xml version="1.0" encoding="utf-8"?>
<TabHost
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@android:id/tabhost"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TabWidget android:id="@android:id/tabs"
android:layout_width="fill_parent"
android:layout_height="68dip"
android:paddingLeft="1dip"
android:paddingRight="1dip"
android:paddingTop="4dip"
/>
<FrameLayout android:id="@android:id/tabcontent"
android:layout_width="fill_parent"
android:layout_height="0dip"
android:layout_weight="1"
/>
</LinearLayout>
</TabHost>

2.二个sub tab对应的layout

Layout1
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#FFF">
<TextView android:id="@+id/textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Tab Widget first">
</TextView>
</LinearLayout>
Layout2
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#FFF">
<TextView android:id="@+id/textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Tab Widget second">
</TextView>
</LinearLayout>

方法2：

先创建一个Activity （TabWidgetDemo）

1.TabWidgetDemo.java
import com.android.exampledemo.R;
import com.android.exampledemo.util.DemoUtils;
import android.app.Activity;
import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
//not use tabhost to organized
public class TabWidgetDemo extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
//int activeTab = DemoUtils.getIntPref(this, "activetab", R.id.artisttab);
SharedPreferences prefs =
getSharedPreferences(getPackageName(), Context.MODE_PRIVATE);
int activeTab = prefs.getInt("activetab", R.id.contactstab);
if (activeTab != R.id.contactstab
&& activeTab != R.id.groupstab) {
activeTab = R.id.contactstab;
}
DemoUtils.activateTab(this, activeTab);
}
}
2.DemoUtils
import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.view.View;
import android.widget.TabWidget;
import com.android.exampledemo.R;
public class DemoUtils {
static int sActiveTabIndex = -1;

public static void activateTab(Activity a,int active_id){
Intent intent = new Intent(Intent.ACTION_PICK);
switch (active_id) {
case R.id.contactstab:
intent.setDataAndType(Uri.EMPTY, "vnd.android.cursor.dir/tb_contacts");
break;
case R.id.groupstab:
intent.setDataAndType(Uri.EMPTY, "vnd.android.cursor.dir/tb_groups");
break;
default:
return;
}
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
a.startActivity(intent);
a.finish();
a.overridePendingTransition(0,0);
}

public static void updateButtonBar(Activity a, int highlight) {
final TabWidget ll = (TabWidget) a.findViewById(R.id.buttonbar);

for (int i = ll.getChildCount() - 1; i >= 0; i--) {
View v = ll.getChildAt(i);
boolean isActive = (v.getId() == highlight);
if (isActive) {
ll.setCurrentTab(i);
sActiveTabIndex = i;
}

v.setTag(i);
v.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
int id = v.getId();
if (id == ll.getChildAt(sActiveTabIndex).getId()) {
return;
}
activateTab((Activity)ll.getContext(),id );
ll.setCurrentTab((Integer) v.getTag());
}});
}
}
}

二个Tab sub activity前一方法中已经给出，这里我们只需要看一下layout的实现就可以了

1>buttonbar.xml

<?xml version="1.0" encoding="utf-8"?>
<TabWidget xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/buttonbar"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<TextView
android:id="@+id/contactstab"
android:focusable="true"
android:drawableTop="@drawable/icon"
android:background="@drawable/buttonbarbackground"
android:text="Contacts"
android:textColor="@color/tab_indicator_text"
android:textAppearance="?android:attr/textAppearanceSmall"
android:paddingTop="7dip"
android:paddingBottom="2dip"
android:gravity="center"
android:layout_weight="1"
android:layout_marginLeft="-3dip"
android:layout_marginRight="-3dip"
android:layout_width="match_parent"
android:layout_height="84dip"
android:singleLine="true"
android:ellipsize="marquee" />
<TextView
android:id="@+id/groupstab"
android:focusable="true"
android:drawableTop="@drawable/icon"
android:background="@drawable/buttonbarbackground"
android:text="Group"
android:textColor="@color/tab_indicator_text"
android:textAppearance="?android:attr/textAppearanceSmall"
android:paddingTop="7dip"
android:paddingBottom="2dip"
android:gravity="center"
android:layout_weight="1"
android:layout_marginLeft="-3dip"
android:layout_marginRight="-3dip"
android:layout_width="match_parent"
android:layout_height="84dip"
android:singleLine="true"
android:ellipsize="marquee" />
</TabWidget>

2>tabwidget_1.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">

<include layout="@layout/battonbar" />

<ExpandableListView android:id="@+id/android:list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:footerDividersEnabled="true"
android:fadeScrollbars="true"
android:drawSelectorOnTop="true">
</ExpandableListView>

</LinearLayout>

3> tabwidget_2.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">

<include layout="@layout/battonbar" />

</LinearLayout>

另外一些资源文件我就不提供了，上面二种方式都可以实现Tabwidget，第一种方法比较通用，第二种可以自定义一些样式，可以做一些比较复杂的View，希望对大家有所帮助！