android viewpager 图片翻页例子

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使用ViewPager这个类可以轻松实现多个页面的滑动功能

viewpager默认在工具界面上是找不到的，需求添加android-support-v4.jar包；

如果没有找到，需要打开Android SDK Manager在Extras中进行下载，最后记得引入工程中并build path。

（不过，我把代码直接COPY到.XML好像就会自动添加了）

例子说明：item01..item08是要翻页的图片，page_indicator_focused，page_indicator_unfocused是显示在底部的点点图片，要自己添加到res\drawable-hdpi\中；

.XML

代码下载：http://pan.baidu.com/s/1mgA7MBY

.JAVA

package com.example.testa; import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.ImageView;
import android.widget.LinearLayout; public class MainActivity extends Activity implements OnPageChangeListener { /**
* ViewPager
*/
private ViewPager viewPager; /**
* 装点点的ImageView数组
*/
private ImageView[] tips; /**
* 装ImageView数组
*/
private ImageView[] mImageViews; /**
* 图片资源id
*/
private int[] imgIdArray; @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewGroup group = (ViewGroup) findViewById(R.id.viewGroup);
viewPager = (ViewPager) findViewById(R.id.viewPager); // 载入图片资源ID
imgIdArray = new int[] { R.drawable.item01, R.drawable.item02,
R.drawable.item03, R.drawable.item04, R.drawable.item05,
R.drawable.item06, R.drawable.item07, R.drawable.item08 }; // 将点点加入到ViewGroup中
tips = new ImageView[imgIdArray.length];
for (int i = 0; i < tips.length; i++) {
ImageView imageView = new ImageView(this);
imageView.setLayoutParams(new LayoutParams(10, 10));
tips[i] = imageView;
if (i == 0) {
tips[i].setBackgroundResource(R.drawable.page_indicator_focused);
} else {
tips[i].setBackgroundResource(R.drawable.page_indicator_unfocused);
} LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
new ViewGroup.LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT));
layoutParams.leftMargin = 5;
layoutParams.rightMargin = 5;
group.addView(imageView, layoutParams);
} // 将图片装载到数组中
mImageViews = new ImageView[imgIdArray.length];
for (int i = 0; i < mImageViews.length; i++) {
ImageView imageView = new ImageView(this);
mImageViews[i] = imageView;
imageView.setBackgroundResource(imgIdArray[i]);
} // 设置Adapter
viewPager.setAdapter(new MyAdapter());
// 设置监听，主要是设置点点的背景
viewPager.setOnPageChangeListener(this);
// 设置ViewPager的默认项, 设置为长度的100倍，这样子开始就能往左滑动
viewPager.setCurrentItem((mImageViews.length) * 100); } /**
*
* @author xiaanming
*
*/
public 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 void destroyItem(View container, int position, Object object) {
} /**
* 载入图片进去，用当前的position 除以图片数组长度取余数是关键
*/
@Override
public Object instantiateItem(View container, int position) {
try {
((ViewPager)container).addView(mImageViews[position % mImageViews.length], 0);
}catch(Exception e){
//handler something
}
return mImageViews[position % mImageViews.length]; } } @Override
public void onPageScrollStateChanged(int arg0) { } @Override
public void onPageScrolled(int arg0, float arg1, int arg2) { } @Override
public void onPageSelected(int arg0) {
setImageBackground(arg0 % mImageViews.length);
} /**
* 设置选中的tip的背景
*
* @param selectItems
*/
private void setImageBackground(int selectItems) {
for (int i = 0; i < tips.length; i++) {
if (i == selectItems) {
tips[i].setBackgroundResource(R.drawable.page_indicator_focused);
} else {
tips[i].setBackgroundResource(R.drawable.page_indicator_unfocused);
}
}
} }