ViewPager+Fragment实现Tabhost，动态添加删除Fragment，可供第三方使用的类库
效果图：
代码实现：ViewPager+Fragment实现了Tabhost，动态添加删除Fragment，暴露三个可重写的多态方法供第三方调用：
protected Fragment getFragmentAt(int pos) {
return null;
}
protected View getIndicatorAt(int pos) {
return null;
}
protected int getItemsCount() {
return 0;
}
项目第三方类库测试用的主MainActivity.java
import java.util.ArrayList;
import java.util.Random;
import android.graphics.Color;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTransaction;
import android.util.Log;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class MainActivity extends FragmentActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Fragment newFragment = new HowToUseThisView();
FragmentTransaction transaction = getSupportFragmentManager()
.beginTransaction();
transaction.replace(R.id.fragment, newFragment);
transaction.commit();
}
public static class HowToUseThisView extends ViewPagerAndFragmentTabHost {
private ArrayList<Fragment> mArrayList;
private int id = 0;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mArrayList = new ArrayList<Fragment>();
}
@Override
protected Fragment getFragmentAt(int pos) {
Fragment fragment = null;
try {
fragment = mArrayList.get(pos);
} catch (Exception e) {
Log.d(this.getClass().getName(), "队列中不存在，创建新Fragment");
}
if (fragment == null) {
fragment = new TestFragment();
((TestFragment) fragment).setID(id++);
mArrayList.add(fragment);
}
return fragment;
}
@Override
protected View getIndicatorAt(int pos) {
// 简单期间，先就用TextView作为底部Tab的选项卡
TextView tv = new TextView(getActivity());
tv.setGravity(Gravity.CENTER);
tv.setText("Tab " + pos);
return tv;
}
@Override
protected int getItemsCount() {
// 假设随机生成此数目的一组Fragment和Tab选项卡
Random rand = new Random();
return rand.nextInt(5);
}
@Override
public void onStart() {
super.onStart();
super.notifyDataSetChanged();
}
}
//
// 仅仅用于测试的Fragment，在ViewPager中加载
//
public static class TestFragment extends Fragment {
private int id;
public void setID(int id) {
this.id = id;
}
public int getID() {
return id;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
TextView tv = new TextView(getActivity());
String str = "序号: " + getID();
tv.setTextColor(Color.LTGRAY);
tv.setText(str);
tv.setTextSize(50);
tv.setGravity(Gravity.CENTER);
return tv;
}
}
}
MainActivity.java需要的activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<FrameLayout
android:id="@+id/fragment"
android:layout_width="match_parent"
android:layout_height="match_parent">
</FrameLayout>
</LinearLayout>
可供第三方调用的ViewPagerAndFragmentTabHost.java类，重点。
import java.util.ArrayList;
import java.util.HashMap;
import java.util.UUID;
import android.graphics.Color;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.view.ViewPager;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.LinearLayout.LayoutParams;
public class ViewPagerAndFragmentTabHost extends Fragment {
private MyFragmentPagerAdapter mPagerAdapter;
private ViewPager mViewPager;
private LinearLayout mLinearLayout;
private ArrayList<HashMap<String, Object>> mArrayList = null;
private final String FRAGMENT = "fragment_tag", TAB = "tab_tag",
UUID_TAG = "uuid_tag";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
mArrayList = new ArrayList<HashMap<String, Object>>();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View mView = inflater.inflate(R.layout.viewpager_fragment, null);
mViewPager = (ViewPager) mView.findViewById(R.id.viewpager);
mLinearLayout = (LinearLayout) mView
.findViewById(R.id.indicator_LinearLayout);
mPagerAdapter = new MyFragmentPagerAdapter(getFragmentManager());
mViewPager.setAdapter(mPagerAdapter);
mViewPager
.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageSelected(int pos) {
set(pos);
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
@Override
public void onPageScrollStateChanged(int arg0) {
}
});
return mView;
}
@Override
public void onStart() {
super.onStart();
// 初始化选择第一项
if (mPagerAdapter.getCount() > 0) {
set(0);
}
for (int i = 0; i < getItemsCount(); i++) {
add(getFragmentAt(i), getIndicatorAt(i));
}
}
public void notifyDataSetChanged() {
mPagerAdapter.notifyDataSetChanged();
}
protected Fragment getFragmentAt(int pos) {
return null;
}
protected View getIndicatorAt(int pos) {
return null;
}
protected int getItemsCount() {
return 0;
}
private void add(Fragment fragment, View indicatorView) {
HashMap<String, Object> map = new HashMap<String, Object>();
UUID uuid = UUID.randomUUID();
map.put(UUID_TAG, uuid);
Bundle args = new Bundle();
fragment.setArguments(args);
map.put(FRAGMENT, fragment);
indicatorView.setBackgroundColor(Color.GRAY);
LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.MATCH_PARENT, 1);
indicatorView.setTag(uuid);
mLinearLayout.addView(indicatorView, params);
indicatorView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
setIndicatorViewSelected(v);
}
});
map.put(TAB, indicatorView);
mArrayList.add(map);
}
private void setIndicatorViewSelected(View v) {
UUID uuid = (UUID) v.getTag();
for (int i = 0; i < mArrayList.size(); i++) {
HashMap<String, Object> map = mArrayList.get(i);
if (uuid == map.get(UUID_TAG)) {
set(i);
}
}
}
private final void delete(int pos) {
UUID uuid = (UUID) mArrayList.get(pos).get(UUID_TAG);
View view = mLinearLayout.findViewWithTag(uuid);
mLinearLayout.removeView(view);
mArrayList.remove(pos);
mPagerAdapter.notifyDataSetChanged();
}
private void setIndicatorViewSelectedColor(int pos) {
for (int i = 0; i < mArrayList.size(); i++) {
HashMap<String, Object> map = mArrayList.get(i);
View view = (View) map.get(TAB);
if (i == pos)
view.setBackgroundColor(Color.RED);
else
view.setBackgroundColor(Color.GRAY);
}
}
private void set(int pos) {
mViewPager.setCurrentItem(pos, true);
setIndicatorViewSelectedColor(pos);
}
private class MyFragmentPagerAdapter extends FragmentStatePagerAdapter {
public MyFragmentPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int pos) {
return (Fragment) mArrayList.get(pos).get(FRAGMENT);
}
@Override
public int getItemPosition(Object object) {
return FragmentPagerAdapter.POSITION_NONE;
}
@Override
public int getCount() {
return mArrayList.size();
}
@Override
public void notifyDataSetChanged() {
super.notifyDataSetChanged();
Log.d(this.getClass().getName(), "notifyDataSetChanged");
}
}
private void onActionAdd() {
add(getFragmentAt(mPagerAdapter.getCount()),
getIndicatorAt(mPagerAdapter.getCount()));
mPagerAdapter.notifyDataSetChanged();
}
private void onActionDelete() {
delete(mViewPager.getCurrentItem());
set(mViewPager.getCurrentItem());
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_add:
onActionAdd();
break;
case R.id.action_dele:
onActionDelete();
break;
default:
break;
}
return super.onOptionsItemSelected(item);
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.main, menu);
}
}
ViewPagerAndFragmentTabHost.java需要的viewpager_fragment.xml :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>
<FrameLayout
android:layout_weight="1"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<android.support.v4.view.ViewPager
android:id="@+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</FrameLayout>
<LinearLayout
android:id="@+id/indicator_LinearLayout"
android:layout_width="match_parent"
android:layout_height="50dip"
android:orientation="horizontal" >
</LinearLayout>
</LinearLayout>
res\menu\main.xml文件：
<menu xmlns:android="http://schemas.android.com/apk/res/android" >
<item
android:id="@+id/action_add"
android:orderInCategory="100"
android:showAsAction="never"
android:title="添加"/>
<item
android:id="@+id/action_dele"
android:orderInCategory="100"
android:showAsAction="never"
android:title="删除"/>
</menu>