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:
public void startActivityFromFragment(Fragment fragment, Intent intent, int requestCode) { if (requestCode == -1) { super.startActivityForResult(intent, -1); return; } if ((requestCode&0xffff0000) != 0) { throw new IllegalArgumentException("Can only use lower 16 bits for requestCode"); } super.startActivityForResult(intent, ((fragment.mIndex+1)<<16) + (requestCode&0xffff)); } @Override protected void 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, "Activity result fragment index out of range: 0x" + Integer.toHexString(requestCode)); return; } Fragment frag = mFragments.mActive.get(index); if (frag == null) { Log.w(TAG, "Activity result 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:
public class BaseFragmentActiviy extends FragmentActivity { private static final String TAG = "BaseActivity"; @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { FragmentManager fm = 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 out of range: 0x" + Integer.toHexString(requestCode)); return; } Fragment frag = fm.getFragments().get(index); if (frag == null) { Log.w(TAG, "Activity result no fragment exists for 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 */ private void 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 */ private void onClickTextViewRemindAdvancetime() { Intent intent = new Intent(); intent.setClass(getActivity(), YourActivity.class); intent.putExtra("TAG","TEST"); getRootFragment().startActivityForResult(intent, 1001); }
作者:老帅