先說一下第一個示例，我做了一個可以拖動但是無法停留的效果，這個效果的實現是在TabHost的setCurrentTab方法裏面加上動畫，所以得自己寫一個TabHost繼承系統的TabHost並重寫setCurrentTab方法。
那麼我就把這個效果的代碼給大家貼出來
package com.hwh.tab;
import android.content.Context;
import android.content.res.Resources;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.animation.Animation;
import android.view.animation.TranslateAnimation;
import android.widget.TabHost;
/*
* 自定義TabHost，使tab切換的時候有動畫效果
*/
public class CustomTabHost extends TabHost {
private Animation slideLeftIn;
private Animation slideLeftOut;
private Animation slideRightIn;
private Animation slideRightOut;
private int tabCount;// tab頁總數
private int device_x; //屏幕寬
public CustomTabHost(Context context, AttributeSet attrs) {
super(context, attrs);
Resources resources = getResources();
DisplayMetrics metrics=resources.getDisplayMetrics();
device_x=metrics.widthPixels;
initAnima();
}
private void initAnima() {
slideLeftIn=new TranslateAnimation(device_x, 0, 1, 1);
slideLeftIn.setDuration(500);
slideRightIn=new TranslateAnimation(-device_x,0,1,1);
slideRightIn.setDuration(500);
slideLeftOut=new TranslateAnimation(0,-device_x,1,1);
slideLeftOut.setDuration(500);
slideRightOut=new TranslateAnimation(0,device_x,1,1);
slideRightOut.setDuration(500);
}
public void setDevice_X(int device_x)
{
this.device_x=device_x;
initAnima();
}
public int getTabCount() {
return tabCount;
}
@Override
public void addTab(TabSpec tabSpec) {
tabCount++;
super.addTab(tabSpec);
}
@Override
public void setCurrentTab(int index) {
// index爲要切換到的tab頁索引，currentTabIndex爲現在要當前tab頁的索引
int currentTabIndex = getCurrentTab();
// 設置當前tab頁退出時的動畫
if (null != getCurrentView()) {// 第一次進入MainActivity時，getCurrentView()取得的值爲空
if (currentTabIndex == (tabCount - 1) && index == 0) {// 處理邊界滑動
getCurrentView().startAnimation(slideLeftOut);
} else if (currentTabIndex == 0 && index == (tabCount - 1)) {// 處理邊界滑動
getCurrentView().startAnimation(slideRightOut);
} else if (index > currentTabIndex) {// 非邊界情況下從右往左fleep
getCurrentView().startAnimation(slideLeftOut);
} else if (index < currentTabIndex) {// 非邊界情況下從左往右fleep
getCurrentView().startAnimation(slideRightOut);
}
}
super.setCurrentTab(index);
// 設置即將顯示的tab頁的動畫
if (currentTabIndex == (tabCount - 1) && index == 0) {// 處理邊界滑動
getCurrentView().startAnimation(slideLeftIn);
} else if (currentTabIndex == 0 && index == (tabCount - 1)) {// 處理邊界滑動
getCurrentView().startAnimation(slideRightIn);
} else if (index > currentTabIndex) {// 非邊界情況下從右往左fleep
getCurrentView().startAnimation(slideLeftIn);
} else if (index < currentTabIndex) {// 非邊界情況下從左往右fleep
getCurrentView().startAnimation(slideRightIn);
}
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
start_x=(int) event.getX();
break;
case MotionEvent.ACTION_UP:
end_x=(int) event.getX();
int len=end_x-start_x;
if(len<0)
{
if(Math.abs(len)>device_x/2)
{
index+=1;
}
//向右
}if(len>0)
{
if(Math.abs(len)>device_x/2)
{
index-=1;
}
}
if(index==count)
{
index=count-1;
}
if(index<0)
{
index=0;
}
tabHost.setCurrentTab(index);
break;
}
return false;
}基於這個原因，我就想能不能把ViewPager和TabHost合併呢，但是有個問題，ViewPager要的是個View，而TabHost裏面是Activity，怎麼把Activity裏的View給得到呢。
一個重要的類：LocalActivityManager，此類有個方法可以得到activity的View，使用startActivity(id, intent).getDecorView()即可得到，其中id可以隨意寫，intent就是對應activity的意圖。思路說完了，下面把代碼貼出來。
顯示佈局文件：
<?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:id="@+id/linearLayout1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TabWidget
android:id="@android:id/tabs"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
</TabWidget>
<android.support.v4.view.ViewPager
android:id="@+id/vPager"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_weight="1.0"
android:background="#000000"
android:flipInterval="30"
android:persistentDrawingCache="animation" />
<FrameLayout
android:id="@android:id/tabcontent"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:visibility="gone" >
</FrameLayout>
</LinearLayout>
</TabHost>package com.hwh.demo;
import java.util.ArrayList;
import java.util.List;
import android.app.LocalActivityManager;
import android.app.TabActivity;
import android.content.Context;
import android.content.Intent;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.os.Bundle;
import android.os.Parcelable;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.view.animation.Animation;
import android.view.animation.TranslateAnimation;
import android.widget.ImageView;
import android.widget.TabHost;
import android.widget.TabHost.OnTabChangeListener;
import android.widget.TextView;
public class DemoActivity extends TabActivity {
//頁卡內容
private ViewPager mPager;
// Tab頁面列表
private List<View> listViews;
// 當前頁卡編號
private LocalActivityManager manager = null;
private final Context context = DemoActivity.this;
private TabHost mTabHost;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.main);
mTabHost = getTabHost();
mTabHost.addTab(mTabHost.newTabSpec("0").setIndicator(
"正在聽").setContent(
new Intent(this, AActivity.class)));
mTabHost.addTab(mTabHost.newTabSpec("1").setIndicator(
"本地聽").setContent(
new Intent(this, BActivity.class)));
mTabHost.addTab(mTabHost.newTabSpec("2").setIndicator(
"網絡聽").setContent(
new Intent(this, CActivity.class)));
mTabHost.setCurrentTab(0);
//tabhost改變同樣改變ViewPager的內容
mTabHost.setOnTabChangedListener(new OnTabChangeListener() {
@Override
public void onTabChanged(String tabId) {
mPager.setCurrentItem(Integer.parseInt(tabId));
}
});
manager = new LocalActivityManager(this, true);
manager.dispatchCreate(savedInstanceState);
InitViewPager();
}
/**
* 初始化ViewPager
*/
private void InitViewPager() {
mPager = (ViewPager) findViewById(R.id.vPager);
listViews = new ArrayList<View>();
MyPagerAdapter mpAdapter = new MyPagerAdapter(listViews);
Intent intent = new Intent(context, AActivity.class);
listViews.add(getView("A", intent));
Intent intent2 = new Intent(context, BActivity.class);
listViews.add(getView("B", intent2));
Intent intent3 = new Intent(context, CActivity.class);
listViews.add(getView("C", intent3));
mPager.setAdapter(mpAdapter);
mPager.setCurrentItem(0);
mPager.setOnPageChangeListener(new MyOnPageChangeListener());
}
/**
* ViewPager適配器
*/
public class MyPagerAdapter extends PagerAdapter {
public List<View> mListViews;
public MyPagerAdapter(List<View> mListViews) {
this.mListViews = mListViews;
}
@Override
public void destroyItem(View arg0, int arg1, Object arg2) {
((ViewPager) arg0).removeView(mListViews.get(arg1));
}
@Override
public void finishUpdate(View arg0) {
}
@Override
public int getCount() {
return mListViews.size();
}
@Override
public Object instantiateItem(View arg0, int arg1) {
((ViewPager) arg0).addView(mListViews.get(arg1), 0);
return mListViews.get(arg1);
}
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == (arg1);
}
@Override
public void restoreState(Parcelable arg0, ClassLoader arg1) {
}
@Override
public Parcelable saveState() {
return null;
}
@Override
public void startUpdate(View arg0) {
}
}
/**
* 頁卡切換監聽，ViewPager改變同樣改變TabHost內容
*/
public class MyOnPageChangeListener implements OnPageChangeListener {
@Override
public void onPageSelected(int arg0) {
switch (arg0) {
case 0:
mTabHost.setCurrentTab(0);
break;
case 1:
mTabHost.setCurrentTab(1);
break;
case 2:
mTabHost.setCurrentTab(2);
break;
}
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
@Override
public void onPageScrollStateChanged(int arg0) {
}
}
private View getView(String id,Intent intent)
{
return manager.startActivity(id, intent).getDecorView();
}
}