ViewPager实现TabHost动态添加、删除Fragment，用红色小圆球指示当前页面
主Activity：MainActivity.java
package zhangphil.viewpager_fragment;
import zhangphil.viewpager_fragment.R;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTransaction;
public class MainActivity extends FragmentActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//创建修改实例
Fragment newFragment =new ViewPagerAndFragmentTabHost();
FragmentTransaction transaction =getSupportFragmentManager().beginTransaction();
// Replace whatever is in thefragment_container view with this fragment,
// and add the transaction to the backstack
transaction.replace(R.id.fragment,newFragment);
//transaction.addToBackStack(null);
//提交修改
transaction.commit();
}
}
layout中的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>
ViewPagerAndFragmentTabHost.java
package zhangphil.viewpager_fragment;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Random;
import java.util.UUID;
import zhangphil.viewpager_fragment.R;
import android.graphics.Color;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
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.view.Gravity;
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;
import android.widget.TextView;
public class ViewPagerAndFragmentTabHost extends Fragment {
private View mView;
private MyFragmentPagerAdapter mPagerAdapter;
private ViewPager mViewPager;
private LinearLayout mLinearLayout;
private CircleIndicatorView mCircleIndicatorView;
private Handler handler;
private final int MESSAGE_WHAT_DRAW_CIRCLE=100;
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) {
mView = inflater.inflate(R.layout.viewpager_fragment, null);
mViewPager = (ViewPager) mView.findViewById(R.id.viewpager);
mLinearLayout = (LinearLayout) mView
.findViewById(R.id.indicator_LinearLayout);
//LinearLayout circleIndicatorView=(LinearLayout)mView.findViewById(R.id.circleIndicatorView_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) {
}
});
mCircleIndicatorView=(CircleIndicatorView)mView.findViewById(R.id.circleIndicatorView);
handler=new Handler(){
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch(msg.what)
{
case MESSAGE_WHAT_DRAW_CIRCLE:
mCircleIndicatorView.setCircleCount(mPagerAdapter.getCount());
mCircleIndicatorView.setCircleSelectedPosition(mViewPager.getCurrentItem());
mCircleIndicatorView.setSelectedCircleRadius(7);
mCircleIndicatorView.setCircleUnSelectedColor(Color.BLUE);
mCircleIndicatorView.drawCircleView();
break;
}
};
};
// 初始化，在此，可选
initialization();
// 初始化选择第一项
if (mPagerAdapter.getCount() > 0){
set(0);
}
return mView;
}
private void initialization() {
//在这里做初始化工作，如果有指定的Fragment，在此预装载
// Fragment fragment;//创建一个Fragment
// View view;//一个下方选项卡的View
// add(fragment, view);
}
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);
handler.sendEmptyMessage(MESSAGE_WHAT_DRAW_CIRCLE);
}
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();
handler.sendEmptyMessage(MESSAGE_WHAT_DRAW_CIRCLE);
}
}
private Fragment loadFragment() {
return new TestFragment();
}
private View loadIndicatorView(int pos) {
TextView tv = new TextView(getActivity());
tv.setGravity(Gravity.CENTER);
tv.setText("Tab " + pos);
return tv;
}
protected void onActionAdd() {
add(loadFragment(), loadIndicatorView(mPagerAdapter.getCount()));
mPagerAdapter.notifyDataSetChanged();
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_add:
onActionAdd();
break;
case R.id.action_dele:
delete(mViewPager.getCurrentItem());
set(mViewPager.getCurrentItem());
break;
default:
break;
}
return super.onOptionsItemSelected(item);
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.main, menu);
}
//
// 仅仅用于测试的Fragment，在ViewPager中加载
//
public static class TestFragment extends Fragment {
private final int seq = new Random().nextInt(20);
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
TextView tv = new TextView(getActivity()) ;
String str="";
for(int i=0;i<500;i++)
str=str+i+"--";
tv.setTextColor(Color.LTGRAY);
tv.setText(str);
return tv;
}
}
}
CircleIndicatorView.java
package zhangphil.viewpager_fragment;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;
public class CircleIndicatorView extends View {
public CircleIndicatorView(Context context, AttributeSet attrs){
super(context, attrs);
}
private int gap=20;//各个横向排列的小球间距
public void setCirlceGap(int gap){
this.gap=padding;
}
public int getCirlceGap(){
return gap;
}
private int padding=20;
public void setPadding(int padding){
this.padding=padding;
}
public int getPadding(){
return padding;
}
private int circle_normal_radius=5; //普通小球半径
public void setNormalCircleRadius(int radius){
this.circle_normal_radius=radius;
}
public int getNormalCircleRadius(){
return circle_normal_radius;
}
private int circle_selected_radius=5; //被选择的小球半径
public void setSelectedCircleRadius(int radius){
this.circle_selected_radius=radius;
}
public int getSelectedCircleRadius(){
return circle_selected_radius;
}
private int count=0;
public void setCircleCount(int count){
this.count=count;
}
public int getCircleCount(){
return count;
}
private int pos=0;
public void setCircleSelectedPosition(int pos){
this.pos=pos;
}
public int getCircleSelectedPosition(){
return pos;
}
public void drawCircleView(){
this.invalidate();
}
private int circleSelectedColor=Color.RED;
public void setCircleSelectedColor(int color){
circleSelectedColor=color;
}
public int getCircleSelectedColor(){
return circleSelectedColor;
}
private int circleUnSelectedColor=Color.LTGRAY;
public void setCircleUnSelectedColor(int color){
circleUnSelectedColor=color;
}
public int getCircleUnSelectedColor(){
return circleUnSelectedColor;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
Paint p = new Paint();
p.setAntiAlias(true);
int w=this.getWidth();
int h=this.getHeight();
//因为是自右往左绘制小圆圈，需要转化pos的位置。
int translate_pos=getCircleCount()-getCircleSelectedPosition()-1;
//如果居中绘制则使用start_x，但需要依次递加x坐标轴位置值。
//int start_x=(w-(CIRCLE_GAP*(getCircleCount()-1)))/2;
for(int i=0;i<getCircleCount();i++){
int r=getNormalCircleRadius();
if(i==translate_pos){
r=getSelectedCircleRadius();
p.setColor(getCircleSelectedColor());
}
else{
r=getNormalCircleRadius();
p.setColor(getCircleUnSelectedColor());
}
//自右向左绘制。从最右边往左边绘制小球
//如果从该自定制的View左边绘制，直接将 x=0即可。
canvas.drawCircle(w-i*getCirlceGap()-getPadding(), h/2, r, p);
}
}
}
效果图：
