ListView 头部ViewPager广告轮询图效果

之前看了别人的一些软件，发现其广告图轮询的时候，那个广告感觉和ViewPager的效果不太一样，后来也查了一下，是因为时间问题，找了一些资料，自己也实践一下。

1、为了解决ListView头部加ViewPager滑动冲突问题，必须自定义ListView，重写里面的onInterceptTouchEvent方法，ListView代码如下：

package com.example.testa;

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.ListView;

public class DefinedListView extends ListView {

	public DefinedListView(Context context) {
		super(context);
	}

	public DefinedListView(Context context, AttributeSet attrs) {
		super(context, attrs);
	}

	public DefinedListView(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
	}

	private float xDistance, yDistance, xLast, yLast;

	@Override
	public boolean onInterceptTouchEvent(MotionEvent ev) {
		switch (ev.getAction()) {
			case MotionEvent.ACTION_DOWN:
				xDistance = yDistance = 0f;
				xLast = ev.getX();
				yLast = ev.getY();
				break;
			case MotionEvent.ACTION_MOVE:
				final float curX = ev.getX();
				final float curY = ev.getY();
				xDistance += Math.abs(curX - xLast);
				yDistance += Math.abs(curY - yLast);
				xLast = curX;
				yLast = curY;
				if (xDistance > yDistance) {
					return false;
				}
		}
		return super.onInterceptTouchEvent(ev);
	}
}

2、为了让广告轮询的速度减慢，必须重新设置ViewPager的Scroller，自定义的Scroller如下：

package com.example.testa;

import java.lang.reflect.Field;

import android.annotation.SuppressLint;
import android.content.Context;
import android.os.Handler;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.animation.Interpolator;
import android.widget.Scroller;

public class DefinedScroller extends Scroller {

	private int DURATION_TIME = 1000;

	private boolean shouldAutoScroll = true;
	private ViewPager viewPager = null;

	@SuppressLint("HandlerLeak")
	private final Handler handler = new Handler() {
		public void handleMessage(android.os.Message msg) {
			if (shouldAutoScroll) {
				viewPager.setCurrentItem(viewPager.getCurrentItem() + 1);
				handler.sendEmptyMessageDelayed(0, 2000);
			}
		};
	};

	public DefinedScroller(Context context) {
		super(context);
	}

	public DefinedScroller(Context context, Interpolator interpolator) {
		super(context, interpolator);
	}

	private View initViewPager(Context context) {
		View view = LayoutInflater.from(context).inflate(R.layout.view_pager_layout, null);
		this.viewPager = (ViewPager) view.findViewById(R.id.viewpager);
		this.viewPager.setOffscreenPageLimit(2);
		this.viewPager.setAdapter(new MyFragmentPagerAdapter(((FragmentActivity) context).getSupportFragmentManager()));
		return view;
	}

	public ViewPager getViewPager() {
		return viewPager;
	}

	public View initView(Context context) {
		View view = initViewPager(context);
		this.viewPager.setOnTouchListener(new OnTouchListener() {

			@Override
			public boolean onTouch(View v, MotionEvent event) {
				if (event.getAction() == MotionEvent.ACTION_UP) {
					shouldAutoScroll = true;
					handler.sendEmptyMessageDelayed(0, 2000);
				} else {
					handler.removeMessages(0);
					shouldAutoScroll = false;
				}
				return false;
			}
		});
		try {
			Field mScroller = ViewPager.class.getDeclaredField("mScroller");
			mScroller.setAccessible(true);
			mScroller.set(viewPager, this);
		} catch (NoSuchFieldException e) {

		} catch (IllegalArgumentException e) {

		} catch (IllegalAccessException e) {

		}
		handler.sendEmptyMessageDelayed(0, 2000);
		return view;
	}

	public void setShouldAutoScroll() {
		handler.removeMessages(0);
		if (viewPager.isShown()) {
			shouldAutoScroll = true;
			handler.sendEmptyMessageDelayed(0, 2000);
		} else {
			shouldAutoScroll = false;
		}
	}

	@Override
	public void startScroll(int startX, int startY, int dx, int dy, int duration) {
		super.startScroll(startX, startY, dx, dy, shouldAutoScroll ? DURATION_TIME : duration);
	}

}

关键是startScroll方法啦

3、其他测试类，

（1）TestFragment：

package com.example.testa;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;

public class TestFragment extends Fragment {

	public int imageResource = 0;

	public static TestFragment newInstance(int imageResource) {
		TestFragment newFragment = new TestFragment();
		newFragment.imageResource = imageResource;
		return newFragment;

	}

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
		View view = inflater.inflate(R.layout.pager_layout, null);
		ImageView textView = (ImageView) view.findViewById(R.id.image);
		textView.setImageResource(imageResource);
		return view;
	}

}

（2）ViewPager的Adapter类：

package com.example.testa;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;

public class MyFragmentPagerAdapter extends FragmentStatePagerAdapter {

	public MyFragmentPagerAdapter(FragmentManager fm) {
		super(fm);
	}

	@Override
	public int getCount() {
		return Integer.MAX_VALUE;
	}

	@Override
	public Fragment getItem(int arg0) {
		switch (arg0 % 4) {
			case 0:
				return TestFragment.newInstance(R.drawable.a1);
			case 1:
				return TestFragment.newInstance(R.drawable.default_wh);
			case 2:
				return TestFragment.newInstance(R.drawable.default_ww);
			case 3:
				return TestFragment.newInstance(R.drawable.test);
			default:
				return TestFragment.newInstance(R.drawable.a1);
		}
	}

}

（3）测试的Activity：

package com.example.testa;

import java.util.ArrayList;
import java.util.List;

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.TextView;

public class MainActivity extends FragmentActivity {

	private DefinedListView listView = null;
	private List list = null;

	private DefinedScroller definedScroller = null;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		listView = (DefinedListView) findViewById(R.id.listview);
		initListData();
		initViewPager();
		listView.setAdapter(new ListAdapter());
		listView.setOnItemClickListener(new OnItemClickListener() {

			@Override
			public void onItemClick(AdapterView parent, View view, int position, long id) {
				definedScroller.getViewPager().setCurrentItem(definedScroller.getViewPager().getCurrentItem() + 1);
			}
		});

		listView.setOnScrollListener(new OnScrollListener() {

			@Override
			public void onScrollStateChanged(AbsListView view, int scrollState) {
				if (scrollState == SCROLL_STATE_IDLE) {
					definedScroller.setShouldAutoScroll();
				}
			}

			@Override
			public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {

			}
		});
	}

	private void initListData() {
		list = new ArrayList();
		for (int i = 1; i <= 20; ++i) {
			list.add("test" + i);
		}
	}

	private void initViewPager() {
		definedScroller = new DefinedScroller(this);
		listView.addHeaderView(definedScroller.initView(this));
	}

	private class ListAdapter extends BaseAdapter {

		@Override
		public int getCount() {
			return list.size();
		}

		@Override
		public Object getItem(int position) {
			return list.get(position);
		}

		@Override
		public long getItemId(int position) {
			return position;
		}

		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			TextView textView = (TextView) LayoutInflater.from(MainActivity.this).inflate(R.layout.text_view_layout,
					null);
			textView.setPadding(20, 20, 20, 20);
			textView.setText(list.get(position));
			return textView;
		}

	}

}

4、布局文件就算了吧

上面有些是在别的地方看到的，很久了，忘记在哪里看到的了，就写不上源地址了，敬请见谅。