Fragment切換問題

片段一： add hind

@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
 switch (checkedId){
 case R.id.rb_common_frame://經常使用框架
 position = 0;
 break;
 case R.id.rb_thirdparty://第三方
 position = 1;
 break;
 case R.id.rb_custom://自定義
 position = 2;
 break;
 case R.id.rb_other://其餘
 position = 3;
 break;
 default:
 position = 0;
 break;
 }

 //根據位置獲得對應的Fragment
 BaseFragment to = getFragment();
 //替換
 switchFrament(mContent,to);

/**
 *
 * @param from 剛顯示的Fragment,立刻就要被隱藏了
 * @param to 立刻要切換到的Fragment，一會要顯示
 */
 private void switchFrament(Fragment from,Fragment to) {
 if(from != to){
 mContent = to;
 FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
 //才切換
 //判斷有沒有被添加
 if(!to.isAdded()){
 //to沒有被添加
 //from隱藏
 if(from != null){
 ft.hide(from);
 }
 //添加to
 if(to != null){
 ft.add(R.id.fl_content,to).commit();
 }
 }else{
 //to已經被添加
 // from隱藏
 if(from != null){
 ft.hide(from);
 }
 //顯示to
 if(to != null){
 ft.show(to).commit();
 }
 }
 }

 }

 /**
 * 根據位置獲得對應的Fragment
 * @return
 */
 private BaseFragment getFragment() {
 BaseFragment fragment = mBaseFragment.get(position);
 return fragment;
 }

片段二：

 private void switchFrament(BaseFragment fragment) {
 //1.獲得FragmentManger
 FragmentManager fm = getSupportFragmentManager();
 //2.開啓事務
 FragmentTransaction transaction = fm.beginTransaction();
 //3.替換
 transaction.replace(R.id.fl_content, fragment);
 //4.提交事務
 transaction.commit();
 }

片段三：

//初始化Fragmet
private void initFragment() {
 fragmentList.clear();
 ItemFragmentOrder itemFragmentOrder = new ItemFragmentOrder();
 ItemFragmentIntent itemFragmentIntent = new ItemFragmentIntent();
 fragmentList.add(itemFragmentOrder);
 fragmentList.add(itemFragmentIntent);
}

//初始化ViewPager
private void initViewPager() {
 mPageAdapter = new MainFragmentPageAdapter(activity.getSupportFragmentManager());
 viewPager.setAdapter(mPageAdapter);
 viewPager.setOffscreenPageLimit(fragmentList.size());
}

//fragmentViewPaager適配器
class MainFragmentPageAdapter extends FragmentPagerAdapter {

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

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

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

//切換頁面
public void showFragment(int position) {
 viewPager.setCurrentItem(position, false);
}

片段四：

@Override
public Fragment getItem(int position) {
 BaseFragment fragment = null;
 switch (fragmentFlag) {
 case FragmentMainVp:
 switch (position) {
 case MainActivity.fristPage:
 fragment = new FragmentFirst();
 break;
 case MainActivity.order:
 fragment = new FragmentOrder();
 break;
 case MainActivity.mine:
 fragment = new FragmentMine();
 break;
 }//end of switch
 break;
 }//end of switch
 Bundle bundle = new Bundle();
 bundle.putInt(BaseFragment.ParamIndex, position);
 if (null != paramBundle) bundle.putBundle(BaseFragment.ParamBundle, paramBundle);
 if (null != fragment) fragment.setArguments(bundle);
 if (null != fragmentAry) fragmentAry[position] = fragment;
 return fragment;
}

@Override
public Object instantiateItem(ViewGroup container, int position) {
 Fragment fragment = (Fragment) super.instantiateItem(container, position);//獲得緩存的fragment
 if (needReload && null != fragment && null != fm) {
 String fragmentTag = fragment.getTag();//獲得tag,這點很重要
 FragmentTransaction ft = fm.beginTransaction();
 if (null != ft) {
 ft.remove(fragment);//移除舊的fragment
 fragment = getItem(position);//換成新的fragment
 ft.add(container.getId(), fragment, fragmentTag);//添加新fragment時必須用前面得到的tag,這點很重要
 ft.attach(fragment);
 fragment.setUserVisibleHint(true);
 ft.commit();
 }//end of if
 if ((getCount() - 1) == position)
 needReload = false;//清除更新標記(只有從新啓動的時候須要去建立新的fragment對象),防止正常狀況下頻繁建立對象
 }//end of if
 return fragment;
}

@Override
public int getCount() {
 return tabTitleCount;}