使用ViewPager实现左右循环滑动

前面一篇文章实现了使用ViewPager实现高仿launcher拖动效果 ，后来很多朋友问能不能实现左右循环滑动效果和引导页面。今天实现了左右滑动，至于在最后一页滑动跳转，这个也做了但是效果不是太好，也希望有实现的朋友能够分享下。在最后一页添加一张图片单击跳转，这个认为很简单大家自己添加个图片，点击后跳转就OK。

这篇是在实现了使用ViewPager实现高仿launcher拖动效果的基础上做了一些小的修改，可以参照前面的。废话不多说了，直接上代码吧！

首先看一些layout下的xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <android.support.v4.view.ViewPager
        android:id="@+id/viewPager"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical" >

        <LinearLayout
            android:id="@+id/viewGroup"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_marginBottom="30dp"
            android:gravity="center_horizontal"
            android:orientation="horizontal" >
        </LinearLayout>
    </RelativeLayout>

</FrameLayout>

和前面一页使用viewpager。使用ViewPager首先需要引入android-support-v4.jar这个jar包。自己不要忘记加。

下面是核心代码：

package cn.com.karl.viewpager;

import java.util.ArrayList;


import android.app.Activity;
import android.content.Intent;
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.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.view.Window;
import android.widget.ImageView;

public class MainActivity extends Activity {
	ViewPager viewPager;
	ArrayList<View> list;
	ViewGroup main, group;
	ImageView imageView;
	ImageView[] imageViews;
	private static int c_id = 0;
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		this.requestWindowFeature(Window.FEATURE_NO_TITLE);
		LayoutInflater inflater = getLayoutInflater();
		list = new ArrayList<View>();
		list.add(inflater.inflate(R.layout.item1, null));
		list.add(inflater.inflate(R.layout.item2, null));
		list.add(inflater.inflate(R.layout.item3, null));
		list.add(inflater.inflate(R.layout.item4, null));
		list.add(inflater.inflate(R.layout.item5, null));

		imageViews = new ImageView[list.size()];
		ViewGroup main = (ViewGroup) inflater.inflate(R.layout.main, null);
		
		ViewGroup group = (ViewGroup) main.findViewById(R.id.viewGroup);

		viewPager = (ViewPager) main.findViewById(R.id.viewPager);

		for (int i = 0; i < list.size(); i++) {
			imageView = new ImageView(MainActivity.this);
			imageView.setLayoutParams(new LayoutParams(12,12));
			//imageView.setPadding(10, 0, 10, 0);
			imageViews[i] = imageView;
			if (i == 0) {
				
				imageViews[i].setBackgroundResource(R.drawable.guide_dot_white);
			} else {
				imageViews[i].setBackgroundResource(R.drawable.guide_dot_black);
			}
			group.addView(imageView);
		}

		setContentView(main);

		viewPager.setAdapter(new MyAdapter());
		viewPager.setOnPageChangeListener(new MyListener());
		viewPager.setCurrentItem(300);
		
	}

	class MyAdapter extends PagerAdapter {

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

		@Override
		public boolean isViewFromObject(View arg0, Object arg1) {
			return arg0 == arg1;
		}

		@Override
		public int getItemPosition(Object object) {
			// TODO Auto-generated method stub
			return super.getItemPosition(object);
		}

		@Override
		public void destroyItem(View arg0, int arg1, Object arg2) {
			// TODO Auto-generated method stub
			//((ViewPager) arg0).removeView(list.get(arg1));
		}

		@Override
		public Object instantiateItem(View arg0, int arg1) {
			// TODO Auto-generated method stub
			    try{
					((ViewPager) arg0).addView(list.get(arg1%list.size()),0);
				    }catch (Exception e) {
						// TODO: handle exception
					}
				return list.get(arg1%list.size());
		}

		@Override
		public void restoreState(Parcelable arg0, ClassLoader arg1) {
			// TODO Auto-generated method stub

		}

		@Override
		public Parcelable saveState() {
			// TODO Auto-generated method stub
			return null;
		}

		@Override
		public void startUpdate(View arg0) {
			// TODO Auto-generated method stub

		}

		@Override
		public void finishUpdate(View arg0) {
			// TODO Auto-generated method stub

		}
	}

	class MyListener implements OnPageChangeListener {

		//当滑动状态改变时调用  
		@Override
		public void onPageScrollStateChanged(int arg0) {
			// TODO Auto-generated method stub
			//arg0=arg0%list.size();
			
		}

		//当当前页面被滑动时调用  
		@Override
		public void onPageScrolled(int arg0, float arg1, int arg2) {
			// TODO Auto-generated method stub
			
		}

		//当新的页面被选中时调用  
		@Override
		public void onPageSelected(int arg0) {
			 if(arg0>2){
				    arg0=arg0%list.size();
				   }
			c_id = arg0;
			for (int i = 0; i < imageViews.length; i++) {
				imageViews[arg0]
						.setBackgroundResource(R.drawable.guide_dot_white);
				if (arg0 != i) {
					imageViews[i]
							.setBackgroundResource(R.drawable.guide_dot_black);
				}
			}
			
			Log.e("-------------", "当前是第"+c_id+"页");
		}

	}
}

代码跟上一篇差不多，大家自己研究吧！下面看下效果：

忘记了，这种效果不太好用图片演示，大家自己演示吧！滑动到最后一张，再滑动就是进入了第一页。下面看下我logcat下的打印：

这里默认是从第0页开始的。