Question

我有以下课程：

public class MyAlertDialogFragment extends DialogFragment {


    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        return new AlertDialog.Builder(getActivity())
                // Set Dialog Icon
                .setIcon(R.drawable.ic_launcher)
                // Set Dialog Title
                .setTitle("Alert DialogFragment")
                // Set Dialog Message
                .setMessage("Alert DialogFragment Tutorial")

                // Positive button
                .setPositiveButton("OK", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        // Do something else
                    }
                })

                // Negative Button
                .setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        // Do something else
                    }
                }).create();
    }
}

和我称之为本课程的另一个班级。

public class ExpandableListAdapter extends BaseExpandableListAdapter {

    private Context _context;
    private List<?> _listDataHeader; // header titles
    // child data in format of header title, child title
    private HashMap<String, List<String>> _listDataChild;

    public ExpandableListAdapter(Context context, List<?> listDataHeader,
            HashMap<String, List<String>> listChildData) {
        this._context = context;
        this._listDataHeader = listDataHeader;
        this._listDataChild = listChildData;
    }

    @Override
    public Object getChild(int groupPosition, int childPosititon) {
        return this._listDataChild.get(this._listDataHeader.get(groupPosition))
                .get(childPosititon);
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

    @Override
    public View getChildView(int groupPosition, final int childPosition,
            boolean isLastChild, View convertView, ViewGroup parent) {
                ....
    }

     ....
         ....

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded,
            View convertView, ViewGroup parent) {


        final Button btn_login = (Button)convertView.findViewById(R.id.btn_login);

        btn_print.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {

                new LineupFragment();


            }
        });

        return convertView;
    }


    public class LineupFragment extends FragmentActivity{

        public LineupFragment() {

              MyAlertDialogFragment alert = new MyAlertDialogFragment();
              alert.show(getSupportFragmentManager(), "Alert_Dialog");
        }

        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);


        }

    }
}

当我点击按钮时，它会给力关闭错误。

 FATAL EXCEPTION: main
Process: com.novum.ideal, PID: 9408
  java.lang.IllegalStateException: Activity has been destroyed
    at android.support.v4.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:1387)
    at android.support.v4.app.BackStackRecord.commitInternal(BackStackRecord.java:636)
    at android.support.v4.app.BackStackRecord.commit(BackStackRecord.java:615)
    at android.support.v4.app.DialogFragment.show(DialogFragment.java:138)
    at com.novum.ideal.ExpandableListAdapter$LineupFragment.<init>(ExpandableListAdapter.java:149)
    at com.novum.ideal.ExpandableListAdapter$1.onClick(ExpandableListAdapter.java:126)
    at android.view.View.performClick(View.java:4463)
    at android.view.View$PerformClick.run(View.java:18770)
    at android.os.Handler.handleCallback(Handler.java:808)
    at android.os.Handler.dispatchMessage(Handler.java:103)
    at android.os.Looper.loop(Looper.java:193)

我想仅显示此类中的对话框。

我怎么能解决它？

Answer 1

您无法在new的子类上使用Activity运算符。活动本身必须经历其生命周期，然后才能将其用作Context的有效DialogFragment。假设您要从ExpandableListAdapter的子类实例化FragmentActivity，而不是保留对Context的引用，您可以引用FragmentActivity / Activity正在使用并使用此功能来检索您需要显示supportFragmentManger DialogFragment的实例。

如果您找到Activity发生onClick事件的方法，那就更好了，让其有责任展示DialogFragment。

E.g

而不是

private Context _context;
public ExpandableListAdapter(Context context

你可以

private FragmentActivity mActivity;
public ExpandableListAdapter(FragmentActivity activity

和onClick

@Override
public void onClick(View v) {
    if (!mActivity.isFinishing()) {
      new MyAlertDialogFragment().show(mActivity.getSupportFragmentManager(), "Alert_Dialog");
    }
}

Answer 2

您无法在构造函数中显示它。如果要在启动活动时显示对话框，请在onCreate方法中执行此操作。看看Activity lifecycle。

按钮单击时不显示DialogFragment

2 个答案: