从DialogFragment回调片段
从DialogFragment回调片段
提问于 2012-12-06 06:04:14
问:如何创建从一个DialogFragment到另一个片段的回调。在我的例子中，涉及的活动应该完全不知道DialogFragment。
考虑到我有
public class MyFragment extends Fragment implements OnClickListener然后在某一时刻我可以做
DialogFragment dialogFrag = MyDialogFragment.newInstance(this);
dialogFrag.show(getFragmentManager, null);MyDialogFragment看起来像什么
protected OnClickListener listener;
public static DialogFragment newInstance(OnClickListener listener) {
DialogFragment fragment = new DialogFragment();
fragment.listener = listener;
return fragment;
}但是，如果DialogFragment暂停并在其生命周期中重新开始，则不能保证侦听器会在附近。片段中唯一的保证是那些通过setArguments和getArguments通过包传递的保证。
如果活动应该是侦听器，则有一种方法可以引用该活动：
public Dialog onCreateDialog(Bundle bundle) {
OnClickListener listener = (OnClickListener) getActivity();
....
return new AlertDialog.Builder(getActivity())
........
.setAdapter(adapter, listener)
.create();
}但我不想让活动监听事件，我需要一个片段。实际上，它可以是任何实现OnClickListener的Java对象。
考虑通过DialogFragment呈现AlertDialog的片段的具体示例。它有“是”/“否”按钮。如何将这些按钮按下发送回创建它的片段？
回答 7
Stack Overflow用户
回答已采纳
发布于 2012-12-06 06:46:54
涉及的活动完全不知道DialogFragment。
片段类：
public class MyFragment extends Fragment {
int mStackLevel = 0;
public static final int DIALOG_FRAGMENT = 1;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (savedInstanceState != null) {
mStackLevel = savedInstanceState.getInt("level");
}
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("level", mStackLevel);
}
void showDialog(int type) {
mStackLevel++;
FragmentTransaction ft = getActivity().getFragmentManager().beginTransaction();
Fragment prev = getActivity().getFragmentManager().findFragmentByTag("dialog");
if (prev != null) {
ft.remove(prev);
}
ft.addToBackStack(null);
switch (type) {
case DIALOG_FRAGMENT:
DialogFragment dialogFrag = MyDialogFragment.newInstance(123);
dialogFrag.setTargetFragment(this, DIALOG_FRAGMENT);
dialogFrag.show(getFragmentManager().beginTransaction(), "dialog");
break;
}
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
switch(requestCode) {
case DIALOG_FRAGMENT:
if (resultCode == Activity.RESULT_OK) {
// After Ok code.
} else if (resultCode == Activity.RESULT_CANCELED){
// After Cancel code.
}
break;
}
}
}
}DialogFragment类：
public class MyDialogFragment extends DialogFragment {
public static MyDialogFragment newInstance(int num){
MyDialogFragment dialogFragment = new MyDialogFragment();
Bundle bundle = new Bundle();
bundle.putInt("num", num);
dialogFragment.setArguments(bundle);
return dialogFragment;
}
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
return new AlertDialog.Builder(getActivity())
.setTitle(R.string.ERROR)
.setIcon(android.R.drawable.ic_dialog_alert)
.setPositiveButton(R.string.ok_button,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
getTargetFragment().onActivityResult(getTargetRequestCode(), Activity.RESULT_OK, getActivity().getIntent());
}
}
)
.setNegativeButton(R.string.cancel_button, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
getTargetFragment().onActivityResult(getTargetRequestCode(), Activity.RESULT_CANCELED, getActivity().getIntent());
}
})
.create();
}
}Stack Overflow用户
发布于 2013-01-07 08:24:33
可能有点晚了，但可能会帮助其他人解决同样的问题，就像我一样。
在显示之前，您可以在Dialog上使用setTargetFragment，并且在对话框中，您可以调用getTargetFragment来获取引用。
Stack Overflow用户
发布于 2012-12-06 07:43:55
您应该在片段类中定义一个interface，并在其父活动中实现该接口。详细信息在此处http://developer.android.com/guide/components/fragments.html#EventCallbacks中概述。代码看起来类似于：
片段：
public static class FragmentA extends DialogFragment {
OnArticleSelectedListener mListener;
// Container Activity must implement this interface
public interface OnArticleSelectedListener {
public void onArticleSelected(Uri articleUri);
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnArticleSelectedListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString() + " must implement OnArticleSelectedListener");
}
}
}活动：
public class MyActivity extends Activity implements OnArticleSelectedListener{
...
@Override
public void onArticleSelected(Uri articleUri){
}
...
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/13733304
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