set textview in custom dialog

Question

I have created a custom dialog but I cannot set a text into the textview that is in the dialog layout from java and my program crashes. what is my mistake?

public class Total_CBC extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.total_cbc);
    final TextView RBC_T = (TextView) findViewById(R.id.total_cbc_text_rbc);

    Button RBC_B = (Button) findViewById(R.id.total_cbc_btn_rbc);

    //

    RBC_B.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
            showCustomDialog(RBC_T);
        }
    });
}


protected void showCustomDialog(final TextView _RBC_T) {
    final Dialog dialog = new Dialog(Total_CBC.this);
    dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
    dialog.setContentView(R.layout.dialog_edit);
    final EditText editText = (EditText) dialog.findViewById(R.id.dialog_edit_edittext);
    Button button = (Button) dialog.findViewById(R.id.dialog_edit_btn);
    TextView titel = (TextView) findViewById(R.id.dialog_edit_text_title);
    titel.setText("RBC");
    button.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            _RBC_T.setText(editText.getText().toString());
            dialog.dismiss();
        }
    });
    dialog.show();
}

} when I deleat this line program work but i need to set text

titel.setText("RBC");

Answer 1

change

 TextView titel = (TextView) findViewById(R.id.dialog_edit_text_title);

to

 TextView titel = (TextView) dialog.findViewById(R.id.dialog_edit_text_title);

Answer 2

You are trying to set the text of the TextView before the dialog is shown and thats why it return null. The correct way is to set the text after the dialog is created:

Put this into your custom dialog

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        TextView titel = (TextView)dialog.findViewById(R.id.dialog_edit_text_title);
        titel.setText("RBC");
        return builder.create();
    }