Question

This question is the followup to the following question:
C# Text don't display on another form after double clicking an item in listbox

Now I have typed my value in the textbox of form3. How am I going to pass back the value to form1 to show it in the listbox10 after pressing “OK” in form3? Below is my form3 coding but it don’t work:

private void button1_Click(object sender, EventArgs e)
{   
    //This is the coding for "OK" button.
    int selectedIndex = listBox10.SelectedIndex;
    listBox10.Items.Insert(selectedIndex, textBox1.Text);
}

Answer 1

You can put public property on form3:

public partial class form3 : Form
{
    public String SomeName
    {
        get
        {
            return textbox1.Text;
        }
    }

    ...
    private void buttonOK_Click(object sender, EventArgs e)
    {
        DialogResult = DialogResult.OK;
        Close();
    }

    private void buttonCancel_Click(object sender, EventArgs e)
    {
        DialogResult = DialogResult.Cancel;
        Close();
    }
 }

In form1, where you are open form3, after ShowDialog, you will write:

if (form3.ShowDialog() == DialogResult.OK)
{

    int selectedIndex = listBox10.SelectedIndex;

    if (selectedIndex == -1) //listbox does not have items
        listbox10.Add(form3.SomeValue);
    else
        listBox10.Items.Insert(selectedIndex, form3.SomeName);
}