使用ViewPager+GridView实现横向滑动的效果(一)
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转载自:http://blog.csdn.net/developer_jiangqq/article/details/9363919
这两天项目要求需要实现一个新功能:要自定义组成实现GridView可以进行横向的滑动,刚开始想了好几种方法,都不行,最后用ViewPager滑动加上Gridview才解决,废话不多说了,直接开始学习。
首先得学习一下ViewPager的使用,网上面关于这个描述很多的,我就是直接复制了一下:
ViewPager类提供了多界面切换的新效果。新效果有如下特征:
[1] 当前显示一组界面中的其中一个界面。
[2] 当用户通过左右滑动界面时,当前的屏幕显示当前界面和下一个界面的一部分。
[3]滑动结束后,界面自动跳转到当前选择的界面中
介绍里面几个比较重要的方法与接口
1,OnPageChangeListener ViewPager页面进行切换监听接口 其中我们经常要实现public void onPageSelected(int arg0),public void onPageScrolled(int arg0, float arg1, int arg2),public void onPageScrollStateChanged(int arg0)着三个方面,其中第一个方法是更多的用到;
2,setCurrentItem(int item),来设置跳转到当前的页面;
3,要显示ViewPager,当然还少不了PagerAdapter类,进行适配;其中我们经常也要实现以下方法才可以:public void destroyItem(View arg0, int arg1, Object arg2),public int getCount(),public Object instantiateItem(View arg0, int arg1),public boolean isViewFromObject(View arg0, Object arg1),具体的使用方法等会看例子就ok了。
好了我们, 直接看代码吧 ,今天来实现一个页面切换的效果截图如下:
MainActivity.java
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- public class MainActivity extends Activity {
- private ViewPager mPager;
- private List<View> listViews;
- private ImageView cursor;
- private TextView t1, t2, t3;
- private int offset = 0;
- private int currIndex = 0;
- private int bmpW;
- @Override
- public void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.main);
- InitImageView();
- InitTextView();
- InitViewPager();
- }
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- private void InitTextView() {
- t1 = (TextView) findViewById(R.id.text1);
- t2 = (TextView) findViewById(R.id.text2);
- t3 = (TextView) findViewById(R.id.text3);
- t1.setOnClickListener(new MyOnClickListener(0));
- t2.setOnClickListener(new MyOnClickListener(1));
- t3.setOnClickListener(new MyOnClickListener(2));
- }
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- private void InitViewPager() {
- mPager = (ViewPager) findViewById(R.id.vPager);
- listViews = new ArrayList<View>();
- LayoutInflater mInflater = getLayoutInflater();
- listViews.add(mInflater.inflate(R.layout.lay1, null));
- listViews.add(mInflater.inflate(R.layout.lay2, null));
- listViews.add(mInflater.inflate(R.layout.lay3, null));
- mPager.setAdapter(new MyPagerAdapter(listViews));
- mPager.setCurrentItem(0);
- mPager.setOnPageChangeListener(new MyOnPageChangeListener());
- }
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- private void InitImageView() {
- cursor = (ImageView) findViewById(R.id.cursor);
- bmpW = BitmapFactory.decodeResource(getResources(), R.drawable.a)
- .getWidth();
- DisplayMetrics dm = new DisplayMetrics();
- getWindowManager().getDefaultDisplay().getMetrics(dm);
- int screenW = dm.widthPixels;
- offset = (screenW / 3 - bmpW) / 2;
- Matrix matrix = new Matrix();
- matrix.postTranslate(offset, 0);
- cursor.setImageMatrix(matrix);
- }
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- public class MyOnClickListener implements View.OnClickListener {
- private int index = 0;
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- public MyOnClickListener(int i) {
- index = i;
- }
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- @Override
- public void onClick(View v) {
- mPager.setCurrentItem(index);
- }
- };
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- public class MyOnPageChangeListener implements OnPageChangeListener {
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- int one = offset * 2 + bmpW;
- int two = one * 2;
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- @Override
- public void onPageSelected(int arg0) {
- Animation animation = null;
- switch (arg0) {
- case 0:
- if (currIndex == 1) {
- animation = new TranslateAnimation(one, 0, 0, 0);
- } else if (currIndex == 2) {
- animation = new TranslateAnimation(two, 0, 0, 0);
- }
- break;
- case 1:
- if (currIndex == 0) {
- animation = new TranslateAnimation(offset, one, 0, 0);
- } else if (currIndex == 2) {
- animation = new TranslateAnimation(two, one, 0, 0);
- }
- break;
- case 2:
- if (currIndex == 0) {
- animation = new TranslateAnimation(offset, two, 0, 0);
- } else if (currIndex == 1) {
- animation = new TranslateAnimation(one, two, 0, 0);
- }
- break;
- }
- currIndex = arg0;
- animation.setFillAfter(true);
- animation.setDuration(300);
- cursor.startAnimation(animation);
- }
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- @Override
- public void onPageScrolled(int arg0, float arg1, int arg2) {
- }
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- @Override
- public void onPageScrollStateChanged(int arg0) {
- }
- }
ViewPager适配器类
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- public class MyPagerAdapter extends PagerAdapter {
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- public List<View> mListViews;
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- public MyPagerAdapter(List<View> mListViews) {
- this.mListViews = mListViews;
- }
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- @Override
- public void destroyItem(View arg0, int arg1, Object arg2) {
- ((ViewPager) arg0).removeView(mListViews.get(arg1));
- }
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- @Override
- public void finishUpdate(View arg0) {
- }
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- @Override
- public int getCount() {
- return mListViews.size();
- }
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- @Override
- public Object instantiateItem(View arg0, int arg1) {
- ((ViewPager) arg0).addView(mListViews.get(arg1), 0);
- return mListViews.get(arg1);
- }
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- @Override
- public boolean isViewFromObject(View arg0, Object arg1) {
- return arg0 == (arg1);
- }
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- @Override
- public void restoreState(Parcelable arg0, ClassLoader arg1) {
- }
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- @Override
- public Parcelable saveState() {
- return null;
- }
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- @Override
- public void startUpdate(View arg0) {
- }
上面那是主要实现功能的代码,详细代码可以在下面链接进行下载
http://download.csdn.net/detail/jiangqq781931404/5774527
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