[Android学习]之解析练习RadioButton+Fragment+viewpager布局架构

public class MainActivity extends FragmentActivity {
    private ViewPager pager;
    private List<Fragment> fragments = new ArrayList<Fragment>();
    private RadioGroup group;
    public static MainActivity pthis;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        pthis = this;
        this.initDate();
        this.initView();
    }
    private void initDate() {
        Fragment fragment1 = new Pager1();
        Fragment fragment2 = new Pager2();
        Fragment fragment3 = new Pager3();
        Fragment fragment4 = new Pager4();
        fragments.add(fragment1);
        fragments.add(fragment2);
        fragments.add(fragment3);
        fragments.add(fragment4);
    }

    

    private void initView() {
        pager = (ViewPager) findViewById(R.id.viewPager);
        pager.setAdapter(new MyPagerAdapter(getSupportFragmentManager()));
        pager.setOverScrollMode(View.OVER_SCROLL_NEVER);
        pager.setOffscreenPageLimit(4);
        group = (RadioGroup) findViewById(R.id.radioGroup);
        group.setOnCheckedChangeListener(new OnCheckedChangeListener() {

            @Override
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                switch (checkedId) {
                case R.id.btn1:
                    break;
                case R.id.btn2:
                    break;
                case R.id.btn3:
                    break;
                }
            }
        });

        pager.setOnPageChangeListener(new OnPageChangeListener() {//监听pager的滚动情况

            @Override
            public void onPageSelected(int position) {
                ((RadioButton) findViewById(group.getChildAt(position).getId())).setClickable(true);
            }

            @Override
            public void onPageScrolled(int position, float positionOffset,int positionOffsetPixels) {}
            @Override
            public void onPageScrollStateChanged(int state) {}
        });
    }
    private class MyPagerAdapter extends FragmentPagerAdapter{

        public MyPagerAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public Fragment getItem(int arg0) {
            return fragments.get(arg0);
        }

        @Override
        public int getCount() {
            return fragments.size();
        }
    }
    @Override
    protected void onDestroy() {
        super.onDestroy();
        }

    private long mTickForShow;       @Override    public void onBackPressed() {
        if (SystemClock.uptimeMillis()-mTickForShow<3000) {
            finish();
        }else{
            Toast.makeText(getApplication(), "再点一次推出程序", 0).show();
        }
        mTickForShow=SystemClock.uptimeMillis();    
    }
}