Getting a value from another form's combobox

Question

I can't get value from form2 combobox. I checked that combobox modifier set to 'Public'.

I get the 'Object not referenced to instance of a object' error. What is the mistake?

//Form1
private DialogIO dio;

private void uosIO_ValueChanged(object sender, EventArgs e)
{
   dio = new DialogIO();
   dio.Show(); // Open Form2 and Set Some value on Combobox
}


// BGWorker get run call from form2 and run it on form1.
private void bgwCustomIO_DoWork(object sender, System.ComponentModel.DoWorkEventArgs e)
{
   MessageBox.Show(dio.uceMinHour.Text); // Show Combobox Value
}

@RenéVogt edited question.BG Worker runs on form1 but form2 triggers it. — john true, Nov 28 '17 at 10:47

score 0 · Answer 1 · answered Nov 28 '17 at 10:49

0

consider check for null also...

 private void bgwCustomIO_DoWork(object sender, System.ComponentModel.DoWorkEventArgs e)
    {
        if (dio == null || string.IsNullOrEmpty(dio.uceMinHour.Text))
        {
            return;
        }
       MessageBox.Show(dio.uceMinHour.Text); // Show Combobox Value
    }

answered Nov 28 '17 at 10:49

Manish Dubey

706
4
17

remove this. it is not null at all. – john true Nov 28 '17 at 10:52
which part dio or the text? – Manish Dubey Nov 28 '17 at 10:54
oh god. just remove this answer. – john true Nov 28 '17 at 11:19
I mean which part cannot be null the instance of dio or the Text property? – Manish Dubey Nov 28 '17 at 11:33

Getting a value from another form's combobox

1 Answers1