SlidingMenu与ViewPager双向滑动的解决方案

最近研究SlidingMenu开源库，发现它里面有一个ViewPagerActivity的例子。但在这个例子中，ViewPager只支持单向滑动。稍作一点修改，即可实现双向滑动。

• 原始的ViewPagerActivity.java代码。

 public class ViewPagerActivity extends BaseActivity {

     public ViewPagerActivity() {
         super(R.string.viewpager);
     }

     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

         ViewPager vp = new ViewPager(this);
         vp.setId("VP".hashCode());
         vp.setAdapter(new ColorPagerAdapter(getSupportFragmentManager()));
         setContentView(vp);

         vp.setOnPageChangeListener(new OnPageChangeListener() {
             @Override
             public void onPageScrollStateChanged(int arg0) {
             }

             @Override
             public void onPageScrolled(int arg0, float arg1, int arg2) {
             }

             @Override
             public void onPageSelected(int position) {
                 switch (position) {
                 case 0:
                     getSlidingMenu().setTouchModeAbove(
                             SlidingMenu.TOUCHMODE_FULLSCREEN);
                     break;
                 default:
                     getSlidingMenu().setTouchModeAbove(
                             SlidingMenu.TOUCHMODE_MARGIN);
                     break;
                 }
             }

         });

         vp.setCurrentItem(0);
         getSlidingMenu().setTouchModeAbove(SlidingMenu.TOUCHMODE_FULLSCREEN);
     }

     public class ColorPagerAdapter extends FragmentPagerAdapter {

         private ArrayList<Fragment> mFragments;

         private final int[] COLORS = new int[] { R.color.red, R.color.green,
                 R.color.blue, R.color.white, R.color.black };

         public ColorPagerAdapter(FragmentManager fm) {
             super(fm);
             mFragments = new ArrayList<Fragment>();
             for (int color : COLORS)
                 mFragments.add(new ColorFragment(color));
         }

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

         @Override
         public Fragment getItem(int position) {
             return mFragments.get(position);
         }

     }

 }

• 改动后的ViewPagerActivity.java代码。

 public class ViewPagerActivity extends BaseActivity {

     public ViewPagerActivity() {
         super(R.string.viewpager);
     }

     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         getSlidingMenu().setSecondaryMenu(R.layout.menu_frame_two);
         getSlidingMenu().setSecondaryShadowDrawable(R.drawable.shadowright);
         getSupportFragmentManager().beginTransaction().replace(R.id.menu_frame_two, new SampleListFragment()).commit();

         ViewPager vp = new ViewPager(this);
         vp.setId("VP".hashCode());
         final ColorPagerAdapter cpa = new ColorPagerAdapter(getSupportFragmentManager());
         vp.setAdapter(cpa);
         setContentView(vp);
         vp.setOnPageChangeListener(new OnPageChangeListener() {
             @Override
             public void onPageScrollStateChanged(int arg0) {
             }

             @Override
             public void onPageScrolled(int arg0, float arg1, int arg2) {
             }

             @Override
             public void onPageSelected(int position) {
                 int lastPostion = cpa.getCount() - 1;
                 //请看这里
                 if (position == 0) {
                     getSlidingMenu().setMode(SlidingMenu.LEFT); // 第一个。SlidingMenu仅有左边有效
                     getSlidingMenu().setTouchModeAbove(SlidingMenu.TOUCHMODE_FULLSCREEN);
                 } else if (position == lastPostion) {
                     getSlidingMenu().setMode(SlidingMenu.RIGHT); // 最后一个。SlidingMenu仅有右边有效
                     getSlidingMenu().setTouchModeAbove(SlidingMenu.TOUCHMODE_FULLSCREEN);
                 } else {
                     getSlidingMenu().setTouchModeAbove(SlidingMenu.TOUCHMODE_NONE); // 中间，SlidingMenu无效
                 }
             }
         });

         vp.setCurrentItem(0);
         getSlidingMenu().setTouchModeAbove(SlidingMenu.TOUCHMODE_FULLSCREEN);
         getSlidingMenu().setMode(SlidingMenu.LEFT);
     }

     public class ColorPagerAdapter extends FragmentPagerAdapter {

         private ArrayList<Fragment> mFragments;

         private final int[] COLORS = new int[] { R.color.red, R.color.green, R.color.blue, R.color.white, R.color.black };

         public ColorPagerAdapter(FragmentManager fm) {
             super(fm);
             mFragments = new ArrayList<Fragment>();
             for (int color : COLORS)
                 mFragments.add(new ColorFragment(color));
         }

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

         @Override
         public Fragment getItem(int position) {
             return mFragments.get(position);
         }

     }

 }