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java – How can I pass values between a Dialog and an Activity?

Posted by: admin April 23, 2020 Leave a comment

Questions:

I am asking the user for input via a Dialog:

package com.android.cancertrials;

import android.app.Dialog;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class CustomDialog extends Dialog  {


    private String name;
//    private ReadyListener readyListener;
     public static EditText etName;
     public String zip;

    public CustomDialog(Context context, String name) {
        super(context);
        this.name = name;
//        this.readyListener = readyListener;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.mycustomdialog);
        setTitle("Enter the Zip Code ");
        Button buttonOK = (Button) findViewById(R.id.ok);
        buttonOK.setOnClickListener(new OKListener());
        etName = (EditText) findViewById(R.id.EditZip);
    }

    private class OKListener implements android.view.View.OnClickListener {
        @Override
        public void onClick(View v) {
//            readyListener.ready(String.valueOf(etName.getText()));
            CustomDialog.this.dismiss();
        }
    }


}

When the user hits OK, how can I pass the value that was entered in the textbox, back to a member variable in the Activity that launched it?

How to&Answers:

You can do that in different ways… actually, if your dialog has only an “OK” button to dismiss, why don’t you just create a custom dialog using the AlertDialog.Builder class instead of subclassing Dialog?

Anyway… let’s suppose you have good reasons to do it the way you did it. In that case, I’d use the ObserverPattern. Something like this:

public class CustomDialog extends Dialog  {


    private String name;
     public static EditText etName;
     public String zip;
    OnMyDialogResult mDialogResult; // the callback

    public CustomDialog(Context context, String name) {
        super(context);
        this.name = name;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        // same you have
    }

    private class OKListener implements android.view.View.OnClickListener {
        @Override
        public void onClick(View v) {
            if( mDialogResult != null ){
                mDialogResult.finish(String.valueOf(etName.getText()));
            }
            CustomDialog.this.dismiss();
        }
    }

    public void setDialogResult(OnMyDialogResult dialogResult){
        mDialogResult = dialogResult;
    }

    public interface OnMyDialogResult{
       void finish(String result);
    }
}

On your activity:

CustomDialog dialog;
// initialization stuff, blah blah
dialog.setDialogResult(new OnMyDialogResult(){
    public void finish(String result){
        // now you can use the 'result' on your activity
    }
});

Reading your code it seems you already tried something similar.

Edit: doing it the easy way

You can still use your mycustomdialog layout. And this is how you would use the AlertDialog.Builder:

LayoutInflater inflater = LayoutInflater.from(YourActivity.this);
final View yourCustomView = inflater.inflate(R.layout.mycustomdialog, null);

final TextView etName = (EditText) yourCustomView.findViewById(R.id.EditZip);
AlertDialog dialog = new AlertDialog.Builder(YourActivity.this)
    .setTitle("Enter the Zip Code")
    .setView(yourCustomView)
    .setPositiveButton("OK", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int whichButton) {
            mSomeVariableYouHaveOnYourActivity = etName.getText().toString();
        }
    })
    .setNegativeButton("Cancel", null).create();
dialog.show();

Answer:

I achieve this through broadcasting intent from [dialog] to [activity].

First passing the activity into the function:

public class DialogFactory {

    public static AlertDialog addSomeDialog(Activity activity) {
        builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                  if (SOMETHING_IS_TRUE) {

                      // prepare your parameters that need to be sent back to activity
                      Intent intent = new Intent(IntentAction.INTENT_ADD_TASK);
                      intent.putExtra(IntentConst.PARAM_A, aInput);
                      intent.putExtra(IntentConst.PARAM_B, bInput);
                      activity.sendBroadcast(intent);

                      Toast.makeText(activity, "Something is TRUE!", Toast.LENGTH_SHORT).show();
                  } else {
                      Toast.makeText(activity, "Something NOT TRUE!", Toast.LENGTH_SHORT).show();
                  }
            }
        });
    }
}

Call above function when some option menu or button clicked in your activity.

Then prepare your activity to receive the intent with BroadcastReceiver in the activity:

private BroadcastReceiver mReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getAction() == IntentAction.INTENT_ADD_TASK) {
             // Do whatever you want to refresh the layout or anything in the activity
             // or even ask fragments inside to act upon it.
             .....
        }
    }
};

Don’t forget to register & un-register the receiver:

@Override
protected void onPause() {
    unregisterReceiver(mReceiver);
    super.onPause();
}

@Override
protected void onResume() {
    super.onResume();
    registerReceiver(mReceiver, new IntentFilter(IntentAction.INTENT_ADD_TASK));
}