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.csdn.net/shuaihj/article/details/46663109