使用Handler实现轮播图

之前写过Banner的使用可以实现轮播图而且非常好用以下的是我之前写的轮播图；

首先是PageAdapter：

public class PagAdapter extends PagerAdapter{
    Context context;
    ArrayList<Tu> tlist;
    public PagAdapter(Context context, ArrayList<Tu> tlist) {
        super();
        this.context = context;
        this.tlist = tlist;
    }
    public PagAdapter() {
        super();
        // TODO Auto-generated constructor stub
    }
    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return Integer.MAX_VALUE;
    }
    @Override
    public boolean isViewFromObject(View arg0, Object arg1) {
        return arg0==arg1;
    }
        @Override
        public Object instantiateItem(ViewGroup container, int position) {
            int pos=position%tlist.size();
            Tu tu = tlist.get(pos);
            View view = LayoutInflater.from(context).inflate(R.layout.tu,null);
            ImageView img=(ImageView)view.findViewById(R.id.img);
            img.setImageResource(tu.img);
            TextView tv=(TextView) view.findViewById(R.id.tv);
            tv.setText(tu.name);
            container.addView(view);
            return view;
        }
        @Override
        public void destroyItem(ViewGroup container, int position, Object object) {
            container.removeView((View)object);
        }
}

然后是实体类：

public class Tu {
    public String name;
    public int img;
    public Tu(String name, int img) {
        super();
        this.name = name;
        this.img = img;
    }
    public Tu() {
        super();
        // TODO Auto-generated constructor stub
    }
    
}

最后是MianActivity：

import java.util.ArrayList;

import android.os.Bundle;
import android.os.Handler;
import android.app.Activity;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;

public class MainActivity extends Activity implements OnPageChangeListener,OnTouchListener{
    ViewPager vp;
    ArrayList<Tu> tlist;
    int[] imgs={R.drawable.a,R.drawable.b,R.drawable.c,R.drawable.d,R.drawable.e,R.drawable.f};
    LinearLayout ll;
    int pre=0;
    Handler handler=new Handler(){
        public void handleMessage(android.os.Message msg) {
            vp.setCurrentItem(vp.getCurrentItem()+1);
            sendEmptyMessageDelayed(999,500);
            
        };
    };
    
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        vp=(ViewPager) findViewById(R.id.vp);
        vp.setOnPageChangeListener(this);
        ll=(LinearLayout) findViewById(R.id.pointLayout);
        tlist=new ArrayList<Tu>();
        for(int i=0;i<imgs.length;i++){
            tlist.add(new Tu("第"+i+"张",imgs[i]));
        }
        for(int i=0;i<imgs.length;i++){
            ImageView view = new ImageView(this);
            LayoutParams params=new LayoutParams(8,8);//这个要倒widget.LinearLayout
            int left=i==0?0:20;
            params.leftMargin = left;
            view.setBackgroundResource(R.drawable.buj);
            view.setEnabled(i==0);
            view.setLayoutParams(params);
            ll.addView(view);
        }
        vp.setAdapter(new PagAdapter(MainActivity.this,tlist));
        int pos=Integer.MAX_VALUE/2%imgs.length;
        int index=Integer.MAX_VALUE/2-pos;
        vp.setCurrentItem(index);
        handler.sendEmptyMessageDelayed(999,500);
        vp.setOnTouchListener(this);
    }
    @Override
    public void onPageScrollStateChanged(int arg0) {
        // TODO Auto-generated method stub
        
    }
    @Override
    public void onPageScrolled(int arg0, float arg1, int arg2) {
        // TODO Auto-generated method stub
        
    }
    @Override
    public void onPageSelected(int arg0) {
        ll.getChildAt(pre).setEnabled(false);
        int pos=arg0%imgs.length;
        pre=pos;
        ll.getChildAt(pos).setEnabled(true);
    }
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:
            handler.removeCallbacksAndMessages(null);
            break;
        case MotionEvent.ACTION_MOVE:
            handler.removeCallbacksAndMessages(null);
            break;
        case MotionEvent.ACTION_UP:
            handler.sendEmptyMessageDelayed(999,250);
            break;
        
      }
        return false;
    
 }
}

drawable包下：

buj:

<selector xmlns:android="http://schemas.android.com/apk/res/android" >
    <item android:state_enabled="true" android:drawable="@drawable/pointy"></item>
    <item android:state_enabled="false" android:drawable="@drawable/pointn"></item>

</selector>

pointn:

<shape xmlns:android="http://schemas.android.com/apk/res/android" 
    android:shape="oval">
    <size 
        android:width="6dp"
        android:height="6dp"
        />    
    <solid android:color="@android:color/white"/>
</shape>

pointy:

<shape xmlns:android="http://schemas.android.com/apk/res/android" 
    android:shape="rectangle">
    <size 
        android:width="6dp"
        android:height="6dp"
        />
    <solid android:color="@android:color/holo_red_dark"/>

</shape>

主布局：

<android.support.v4.view.ViewPager
        android:id="@+id/vp"
        android:layout_width="match_parent"
        android:layout_height="200dp">


    </android.support.v4.view.ViewPager>
    <LinearLayout
        android:id="@+id/pointLayout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@id/vp"
        android:layout_centerHorizontal="true"
        android:orientation="horizontal" >
    </LinearLayout>

tu:

<ImageView
        android:id="@+id/img"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:src="@mipmap/a" />
    <TextView
        android:id="@+id/tv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="sss"
        android:textSize="22sp"
        android:padding="8dp"
        android:gravity="center"
        />

dimens:

<dimen name="activity_horizontal_margin">16dp</dimen>
    <dimen name="activity_vertical_margin">16dp</dimen>

图片需要自己换，这是我之前写的；