* Label : 1
* RadioButtonList : 1 (上書き許容・禁止を指定。プロパティ「Items」に、「permit」および「forbid」を指定)
* FileUpload : 1
* Button : 1
サンプル
Protected Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim postFile As HttpPostedFile = Me.FileUpload1.PostedFile
Dim upPath As String = Server.MapPath("~/App_Data/" & Path.GetFileName(postFile.FileName))
If RadioButtonList1.SelectedValue = "forbid" And File.Exists(upPath) Then
Me.Label1.Text = "There is the same file name in the folder."
Else
If postFile.ContentType = "image/jpeg" Then
postFile.SaveAs(upPath)
Me.Label1.Text = postFile.FileName & " is uploaded."
Else
Me.Label1.Text = "Sorry... This system can upload only Jpeg images."
End If
End If
End Sub