Public ReadOnly Property IsDefault As Boolean

public bool IsDefault {get;}

Imports Infragistics.Shared
Imports Infragistics.Win
Imports Infragistics.Win.Misc

Private Sub InitializeDialogButtons()
    Me.btnCancel.Text = "&Cancel"
    Me.btnCancel.DialogResult = DialogResult.Cancel
    Me.CancelButton = Me.btnCancel

    Me.btnOk.Text = "OK"
    Me.btnOk.DialogResult = DialogResult.OK
    Me.AcceptButton = Me.btnOk
End Sub

Private Sub btnOk_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnOk.Click
    Dim allowClose As Boolean = True

    'process the ok click

    If Not allowClose Then
        'clear the dialog result so it won't close
        Me.DialogResult = DialogResult.None
    Else
        Me.Close()
    End If
End Sub

Private Sub btnCancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCancel.Click
    'cancel and close
    Me.Close()
End Sub

using Infragistics.Shared;
using Infragistics.Win;
using Infragistics.Win.Misc;

private void InitializeDialogButtons()
{
	this.btnCancel.Text = "&Cancel";
	this.btnCancel.DialogResult = DialogResult.Cancel;
	this.CancelButton = this.btnCancel;

	this.btnOk.Text = "OK";
	this.btnOk.DialogResult = DialogResult.OK;
	this.AcceptButton = this.btnOk;
}

private void btnOk_Click(object sender, System.EventArgs e)
{
	bool allowClose = true;

	//process the ok click

	if (!allowClose)
	{
		//clear the dialog result so it won't close
		this.DialogResult = DialogResult.None;
	}
	else
		this.Close();
}

private void btnCancel_Click(object sender, System.EventArgs e)
{
    //cancel and close
	this.Close();
}