我正确吗？

Question

我在学习和记住Android，我想了解我的错误。 这是我确认/取消AlertDialog类。创造了它在不同的类拆分代码，而不是把一切都放在一个活动：

public class ConversationAlertDialog extends DialogFragment { 

    public static Dialog createDialog(Context context) { 
     // Use the Builder class for convenient dialog construction 
     AlertDialog.Builder builder = new AlertDialog.Builder(context); 

     builder.setMessage("Continue?") 
       .setPositiveButton("Yes", new DialogInterface.OnClickListener() { 
        public void onClick(DialogInterface dialog, int id) { 
         // User confirms 

        } 
       }) 
       .setNegativeButton("No", new DialogInterface.OnClickListener() { 
        public void onClick(DialogInterface dialog, int id) { 
         // User cancelled 
        } 
       }); 
     // Create the AlertDialog object and return it 
     return builder.create(); 
    } 
} 

这是我的活动，我展示AlertDialog：

buttonConvert.setOnClickListener(new View.OnClickListener() { 
     public void onClick(View v) { 
      ConversationAlertDialog.createDialog(ConversionActivity.this).show(); 
     } 
    }); 

接下来，我想创建回调，所以我可以写对话取消/确认活动中的行为。这样，使用已经写在Activity中的代码也会更容易。我还在学习回调所以不确定，但我认为我应该实现接口。

所有类型的提示将帮助我。

Answer 1

他是我使用的代码。我发现它非常灵活，因为您可以创建几个类似的对话框，用于稍微不同的任务。您将需要创建一个布局文件 - 这会为您提供很大的功能和风格灵活性。

我的布局文件是fragment_ok_cancel_dialog。

在调用对话框的Activity中，您需要实现Listener。

implements OkCancelDialogFragment.OkCancelDialogListener 

另一个优点是与我的代码，你可以改变标题和消息，以适应任何活动的需要。

private void callMyDialog(){ 
    //Customize the title and message as needed 
    String title = "This is my dialog title"; 
    String mess = "This is my dialog message"; 
    OkCancelDialogFragment dialog = OkCancelDialogFragment.newInstance(title, mess); 
    dialog.show(getFragmentManager(), "OkCancelDialogFragment2"); 
} 

现在您需要在调用DialogFragment的Activity中实现对话框回调。

@Override 
public void onFinishOkCancelDialog(boolean submit) { 
    if(submit){ 
     // Do something positive 
    } 
    else{ 
     // Do something negative 
    } 
} 

现在为DialogFragment代码：

public class OkCancelDialogFragment extends DialogFragment { 

    private static final String ARG_TITLE = "title"; 
    private static final String ARG_MESSAGE = "message"; 

    Context context = null; 

    private String title; 
    private String message; 
    private boolean submitData = false; 

    private OkCancelDialogListener mListener; 

    public OkCancelDialogFragment() { 
    } 

    public static OkCancelDialogFragment newInstance(String title, String message) { 
     OkCancelDialogFragment fragment = new OkCancelDialogFragment(); 
     Bundle args = new Bundle(); 
     args.putString(ARG_TITLE, title); 
     args.putString(ARG_MESSAGE, message); 
     fragment.setArguments(args); 
     return fragment; 
    } 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     if (getArguments() != null) { 
      title = getArguments().getString(ARG_TITLE); 
      message = getArguments().getString(ARG_MESSAGE); 
     } 
    } 

    @Override 
    public Dialog onCreateDialog(Bundle saveIntsanceState){ 

     context = getActivity(); 

     AlertDialog.Builder builder = new AlertDialog.Builder(getActivity()); 

     LayoutInflater inflater = getActivity().getLayoutInflater(); 

     View rootView = inflater.inflate(R.layout.fragment_ok_cancel_dialog, null, false); 
     final TextView titleView = (TextView)rootView.findViewById(R.id.tvTitle); 
     final TextView messView = (TextView)rootView.findViewById(R.id.tvMessage); 

     titleView.setText(title); 
     messView.setText(message); 

     builder.setView(rootView) 
//    .setTitle(title) 
       .setPositiveButton(R.string.ok_button_dialog_title, new DialogInterface.OnClickListener() { 
        @Override 
        public void onClick(DialogInterface dialog, int which) { 

         submitData = true; 
         if(mListener == null) mListener = (OkCancelDialogListener) context; 
         mListener.onFinishOkCancelDialog(submitData); 
        } 
       }) 
       .setNegativeButton("Cancel", new DialogInterface.OnClickListener() { 
        @Override 
        public void onClick(DialogInterface dialog, int which) { 
         submitData = false; 
         if(mListener == null) mListener = (OkCancelDialogListener) context; 
         mListener.onFinishOkCancelDialog(submitData); 
        } 
       }); 
     return builder.create(); 
    } 


    @Override 
    public void onAttach(Context context) { 
     super.onAttach(context); 
     try { 
      if(mListener == null) mListener = (OkCancelDialogListener) context; 
     } 
     catch (Exception ex){ 
      throw new RuntimeException(context.toString() 
        + " must implement OnFragmentInteractionListener"); 
     } 
    } 

    @Override 
    public void onDetach() { 
     super.onDetach(); 
     mListener = null; 
    } 


    public interface OkCancelDialogListener { 
     void onFinishOkCancelDialog(boolean submit); 
    } 

} 

请注意，.setTitle(title)是有效的API 23或更高版本（或者API 21或更高？）。

Answer 2

在ConversationAlertDialog类中创建一个接口。

public interface onActionSelect{ 
void onOkSelect(); 
void onCancelSelect(); 
} 

在Activity上实现它，并将其传递给ConversationAlertDialog类。然后从那样的对话中调用。

// For Positive Button Click 
    public void onClick(DialogInterface dialog, int id) { 
    // User confirms 
    if(mCallBack != null) mCallBack.onOkSelect() 
} 

    // For Negative Button Click 
    public void onClick(DialogInterface dialog, int id) { 
    // User confirms 
    if(mCallBack != null) mCallBack.onCancelSelect() 
} 

当正面或负面的按钮被点击时，您将会在MainActivity中收到通知。

Answer 3

public class ConversationAlertDialog extends DialogFragment { 
    private onMyEvent event; 
    public void setMyEvent(onMyEvent e) 
    { 
     this.event=e; 
    } 
    public static Dialog createDialog(Context context) { 
     // Use the Builder class for convenient dialog construction 
     AlertDialog.Builder builder = new AlertDialog.Builder(context); 

     builder.setMessage("Continue?") 
       .setPositiveButton("Yes", new DialogInterface.OnClickListener() { 
        public void onClick(DialogInterface dialog, int id) { 
         // User confirms 
         if(null!=event) 
         { 
          event.ok(); 
         } 
        } 
       }) 
       .setNegativeButton("No", new DialogInterface.OnClickListener() { 
        public void onClick(DialogInterface dialog, int id) { 
         if(null!=event) 
         { 
          event.cancel(); 
         } 
         // User cancelled 
        } 
       }); 
     // Create the AlertDialog object and return it 
     return builder.create(); 
    } 
    public interface onMyEvent{ 
     void ok(); 
     void cancel(); 
    } 
} 

buttonConvert.setOnClickListener(new View.OnClickListener() { 
    public void onClick(View v) { 
     Dialog dialog=ConversationAlertDialog.createDialog(ConversionActivity.this); 
     dialog.setMyEvent(new onMyEvent{....}) 
     dialog.show(); 
    } 
});