Handle click of custom dialog class with custom view from fragment or activity

Question

In custom dialog class with the custom view, I want to handle click of the button from Activity or fragment, I have created an interface for handling the button click but showing error.

Attempt to invoke interface method 'void com.ymcaspi.util.CustomDialog$DialogInterface.doLogin(com.ymcaspi.util.CustomDialog)' on a null object reference

My dialog class is

public class CustomDialog extends Dialog implements
    android.view.View.OnClickListener {
public Activity activity;
public Button btnYes, btnNo;
CustomDialog customDialog;
public CustomDialog(Activity activity) {
    super(activity);
    this.activity = activity;
}

DialogInterface dialogInterface;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.alert_login);
    btnYes = (Button) findViewById(R.id.btn_yes);
    btnNo = (Button) findViewById(R.id.btn_no);
    btnYes.setOnClickListener(this);
    btnNo.setOnClickListener(this);
}
//in custom adapter class i want to handle click of button from Activity or fragment, I have created a interface for handling button click
//but showing
@Override
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.btn_yes:
            customDialog=new CustomDialog(activity);
            dialogInterface.doLogin(customDialog);
            break;
        case R.id.btn_no:
            dismiss();
            break;
        default:
            break;
    }
    dismiss();
}



  public interface DialogInterface{
        void doLogin(CustomDialog dialog);

   }
}

i have implemented this interface in fragment but not working?

Apparently, your `dialogInterface` was never assigned, what did you intend to do with it? — Aaron, Nov 21 '18 at 08:05
Possible duplicate of [What is a NullPointerException, and how do I fix it?](https://stackoverflow.com/questions/218384/what-is-a-nullpointerexception-and-how-do-i-fix-it) — Aaron, Nov 21 '18 at 08:06
@Aaron i want to close dialog from activity when my task is done. — Farhana Naaz Ansari, Nov 21 '18 at 08:43
@farhana In that case, you could create a method `doLogin` in the same class without having an interface. — Aaron, Nov 21 '18 at 08:45
@Aaron i can but i want to call service from activity.then how can i do that? — Farhana Naaz Ansari, Nov 21 '18 at 08:48
my simple point is i want to call this dialog from activities and thier button should be handle from activiyt. — Farhana Naaz Ansari, Nov 21 '18 at 08:54

Arash GM · Answer 1 · 2018-11-21T10:10:51.950

2

You didn't initialize dialogInterface on your dialog , if you've implemented the interface on your Activity , set your Activity to dialog interface

public CustomDialog(Activity activity,DialogInterface dialogInterface ) {
    super(activity);
    this.activity = activity;
    this.dialogInterface = dialogInterface ;
}

edited Nov 21 '18 at 10:10

answered Nov 21 '18 at 08:07

Arash GM

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... or pass an instance of `DialogInterface` to constructor or by setter – Andrey Busik Nov 21 '18 at 08:27
@AndreyBusik can explain properly. – Farhana Naaz Ansari Nov 21 '18 at 08:36
i want to call service in `doLogin` after response wants to dismiss dialog. – Farhana Naaz Ansari Nov 21 '18 at 08:39
@farhana : you have the instance of the dialog in your Activity , so after receiveing your response you can check the dialog is shown or not , then dismiss that. – Arash GM Nov 21 '18 at 08:48
@ArashGM i did this, showing incompatible type and I have also implemented the interface in fragment and activity too. – Farhana Naaz Ansari Nov 21 '18 at 08:51
@ArashGM i made the small change which resolves the problem of incompatibility. thanks for answering. – Farhana Naaz Ansari Nov 21 '18 at 09:15

score 0 · Accepted Answer · answered Nov 21 '18 at 08:58

Here's one example that you can try if you intend to receive callback on your activity from the dialog:

class YourActivity extends Activity implements DialogInterface {

    void showDialog() {
        CustomDialog dialog = // init your CustomDialog
        dialog.setOnLoginClickListener(this);
        dialog.show();
    }

    void doLogin() {
        // Button yes has been clicked, do stuff... 
    }
}

And create a method to assign the listener in your CustomDialog class:

public class CustomDialog extends Dialog implements OnClickListener {

    private DialogInterface dialogInterface;

    public void setOnLoginClickListener(DialogInterface dialogInterface) {
        this.dialogInterface = dialogInterface;
    }
}

I get the concept from your code, I made a small change, your `setOnLoginClickListener` giving me Dialog ref. so I passed the ref. of the interface in constructer. Actually I' was comparing `Activity` to Interface but i was confused. — Farhana Naaz Ansari, Nov 21 '18 at 09:12

Handle click of custom dialog class with custom view from fragment or activity

2 Answers2