Android循环ViewPager(二)

十度 Android 2015年12月01日收藏

上午没事写了一篇，下午有事，晚上回来看看感觉写的差点意思，上篇文章大概的关于循环是自己添加了两个空的View，看到网上还有一种就是在自定义的Adapter中getCount中返回最大值，然后destroyItem不删除View，添加异常，说了这么多，我实验之后总是有问题，如果有弄成功的可以告知我一下，我的是三张图片~还是按照上午的那种方式就是第一个和最后一个是空View:

基础布局

看下效果吧，加了一排小圈圈，比上午的那个Demo好看:

activity_pager.xml:

<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_pic"  
        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_pic"  
            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>

　　实现Demo

自定义一个MyPicViewPagerAdapter:

		private class MyPicViewPagerAdapter extends PagerAdapter {

		@Override
		public int getCount() {
			// TODO Auto-generated method stub
			return viewList.size();
		}

		@Override
		public boolean isViewFromObject(View arg0, Object arg1) {
			// TODO Auto-generated method stub
			return arg0 == arg1;
		}

		@Override
		public void destroyItem(ViewGroup container, int position, Object object) {
			// TODO Auto-generated method stub
			container.removeView(viewList.get(position));
		}

		@Override
		public Object instantiateItem(ViewGroup container, int position) {
			// TODO Auto-generated method stub
			container.addView(viewList.get(position), 0);
			return viewList.get(position);

		}

	}

　activity中的字段:

	private ViewPager viewPager;
	private int[] srcArr = new int[] { R.drawable.eagle, R.drawable.heron,
			R.drawable.flamingo };
	private ViewGroup viewGroup;
	private List<View> viewList;
	private ImageView[] cycleList;

　activity中的onCreate中实例化的ViewPager和ViewGroup，实例化的时候加入参数

		viewPager = (ViewPager) findViewById(R.id.viewPager_pic);
		viewGroup = (ViewGroup) findViewById(R.id.viewGroup_pic);
		viewList = new ArrayList<View>();
		viewList.add(new View(this));
		for (int i = 0; i < srcArr.length; i++) {
			ImageView imageView = new ImageView(this);
			imageView.setBackgroundResource(srcArr[i]);
			viewList.add(imageView);
		}
		viewList.add(new View(this));
		// 加载小圆圈
		cycleList = new ImageView[srcArr.length];
		for (int i = 0; i < cycleList.length; i++) {
			ImageView imageView = new ImageView(this);
			imageView.setLayoutParams(new LayoutParams(10, 10));
			cycleList[i] = imageView;
　　　　　　　　　　　　　　//0的时候选中
			if (i ==0) {
				cycleList[i].setBackgroundResource(R.drawable.page_indicator_selected);
			} else {
				cycleList[i].setBackgroundResource(R.drawable.page_indicator_unselected);
			}

			LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
					new ViewGroup.LayoutParams(LayoutParams.WRAP_CONTENT,
							LayoutParams.WRAP_CONTENT));
			layoutParams.leftMargin = 5;
			layoutParams.rightMargin = 5;
			viewGroup.addView(imageView, layoutParams);
		}
		viewPager.setAdapter(new MyPicViewPagerAdapter());
		viewPager.setCurrentItem(1);

　　Demo重要的是循环，由于是有五个View，三个小圈圈，所以就需要改变一下选中的setOnPageChangeListener:

viewPager.setOnPageChangeListener(new OnPageChangeListener() {

			@Override
			public void onPageSelected(int arg0) {
				// TODO Auto-generated method stub
				for (int i = 0; i < cycleList.length; i++) {
					cycleList[i].setBackgroundResource(R.drawable.page_indicator_unselected);
					if (i == arg0-1) {
						cycleList[i].setBackgroundResource(R.drawable.page_indicator_selected);
					}
				}
				 if(arg0 == 0)
				 viewPager.setCurrentItem(viewList.size()-2);
				 else if(arg0 == viewList.size() - 1)
				 viewPager.setCurrentItem(1);
			}

			@Override
			public void onPageScrolled(int arg0, float arg1, int arg2) {
				// TODO Auto-generated method stub

			}

			@Override
			public void onPageScrollStateChanged(int arg0) {
				// TODO Auto-generated method stub

			}
		});

　　最后看下效果图: