C# と VB.NET の質問掲示板

form1
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) _
            Handles Button1.Click

        Dim f2 As New Form2
        Dim dr As DialogResult = f2.ShowDialog()

        MessageBox.Show(dr)


    End Sub

Public Class Form2

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) _
        Handles Button1.Click
        Dim sfd As New SaveFileDialog()
        sfd.CheckFileExists = True
        Dim dr As DialogResult = sfd.ShowDialog()

        MessageBox.Show(dr)

    End Sub
End Class

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Form2 f2 = new Form2();

            DialogResult dr = f2.ShowDialog();

            MessageBox.Show(dr.ToString());
        }
    }
}

namespace WindowsFormsApplication1
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            SaveFileDialog sfd = new SaveFileDialog();
            sfd.CheckFileExists = true;
            DialogResult dr = sfd.ShowDialog();

            MessageBox.Show(dr.ToString());

        }
    }
}

VBもC# も上書き存在確認のダイアログメッセージが普通に出たけど、こーゆーことではなくて？