Android的Fragment中onActivityResult不被调用的解决方案

常见的，我们会在FragmentActivity中嵌套一层Fragment使用，甚至Fragment下层层嵌套使用。这个时候，在第二级或者更深级别的Fragment将无法收到onActivityResult回调，查看FragementActivity的源码发现：

publicvoid startActivityFromFragment(Fragmentfragment, Intent intent,  

             int requestCode) {

         if (requestCode == -1) {

             super.startActivityForResult(intent, -1);

             return;

         }

         if ((requestCode&0xffff0000) != 0) {

             thrownew IllegalArgumentException("Can only use lower 16 bits for requestCode");

         }

         super.startActivityForResult(intent,((fragment.mIndex+1)<<16) + (requestCode&0xffff));

     }

     @Override

     protectedvoid onActivityResult(int requestCode, int resultCode, Intent data) {

        mFragments.noteStateNotSaved();

         int index = requestCode>>16;

         if (index != 0) {

            index--;

             if (mFragments.mActive == null || index < 0 || index >= mFragments.mActive.size()) {

                Log.w(TAG, "Activityresult fragment index out of range: 0x"

                        + Integer.toHexString(requestCode));

                 return;

             }

            Fragment frag = mFragments.mActive.get(index);

             if (frag == null) {

                Log.w(TAG, "Activityresult no fragment exists for index: 0x"

                        + Integer.toHexString(requestCode));

             } else {

                 frag.onActivityResult(requestCode&0xffff, resultCode, data);

             }

             return;

         }

          

         super.onActivityResult(requestCode, resultCode,data);

     }

  

原来，程序猿偷懒，没有处理嵌套Fragment的情况，也就是说回调只到第一级Fragment，就没有继续分发。我们可以实现一个自己的FragmentActiviy，来实现继续分发，如下：

publicclassBaseFragmentActiviyextendsFragmentActivity {

 privatestaticfinal String TAG = "BaseActivity";

 

 @Override

 protectedvoid onActivityResult(int requestCode, int resultCode, Intent data) {

  FragmentManagerfm = getSupportFragmentManager();

  int index = requestCode >> 16;

  if (index != 0) {

   index--;

   if (fm.getFragments() == null || index < 0

     || index >=fm.getFragments().size()) {

    Log.w(TAG, "Activity result fragment index outof range: 0x"

      +Integer.toHexString(requestCode));

    return;

   }

   Fragment frag =fm.getFragments().get(index);

   if (frag == null) {

    Log.w(TAG, "Activity result no fragment existsfor index: 0x"

      +Integer.toHexString(requestCode));

   } else {

    handleResult(frag,requestCode, resultCode, data);

   }

   return;

  }

 

 }

 

 /**

  * 递归调用，对所有子Fragement生效

  *

  * @param frag

  * @param requestCode

  * @param resultCode

  * @param data

  */

 privatevoid handleResult(Fragment frag, int requestCode, int resultCode,

   Intent data) {

 frag.onActivityResult(requestCode & 0xffff, resultCode, data);

 List<Fragment> frags =frag.getChildFragmentManager().getFragments();

  if (frags != null) {

   for (Fragment f : frags) {

    if (f != null)

     handleResult(f,requestCode, resultCode, data);

   }

  }

 }

然后我们继承这个BaseFragmentActivity即可，但是要注意，在Fragment中启动Activity时，一定要调用根Fragment的启动方法，如下：

/**

  * 得到根Fragment

  *

  * @return

  */

 private Fragment getRootFragment() {

  Fragment fragment= getParentFragment();

  while (fragment.getParentFragment() != null) {

   fragment =fragment.getParentFragment();

  }

  return fragment;

 

 }

 

 /**

  * 启动Activity

  */

 privatevoid onClickTextViewRemindAdvancetime() {

  Intent intent = new Intent();

 intent.setClass(getActivity(), YourActivity.class);

  intent.putExtra("TAG","TEST");

 getRootFragment().startActivityForResult(intent, 1001);

 }

原文地址：http://blog.youkuaiyun.com/shuaihj/article/details/46663109