下列範例顯示如何使用上載檔案。程式碼會對照硬式編碼的允許副檔名清單，檢查上載檔案的副檔名，並拒絕所有其他類型的檔案。然後，檔案會寫入至目前網站的 UploadedImages 資料夾中。上載檔案會以它在用戶端電腦上具有的相同檔案名稱來儲存。系統會使用 FileUpload 控制項的 FileName 屬性，這是因為 HttpPostedFile 物件的 FileName 屬性會傳回檔案在用戶端電腦上的完整路徑。
Protected Sub Page_Load(ByVal sender As Object,
ByVal e As System.EventArgs) Handles Me.Load
If IsPostBack Then
Dim path As String = Server.MapPath("~/UploadedImages/")
Dim fileOK As Boolean = False
If FileUpload1.HasFile Then
Dim fileExtension As String
fileExtension = System.IO.Path. _
GetExtension(FileUpload1.FileName).ToLower()
Dim allowedExtensions As String() = _
{".jpg", ".jpeg", ".png", ".gif"}
For i As Integer = 0 To allowedExtensions.Length - 1
If fileExtension = allowedExtensions(i) Then
fileOK = True
End If
Next
If fileOK Then
Try
FileUpload1.PostedFile.SaveAs(path & _
FileUpload1.FileName)
Label1.Text = "File uploaded!"
Catch ex As Exception
Label1.Text = "File could not be uploaded."
End Try
Else
Label1.Text = "Cannot accept files of this type."
End If
End If
End If
End Sub
protected void Page_Load(object sender, EventArgs e)
{
if(IsPostBack)
{
Boolean fileOK = false;
String path = Server.MapPath("~/UploadedImages/");
if (FileUpload1.HasFile)
{
String fileExtension =
System.IO.Path.GetExtension(FileUpload1.FileName).ToLower();
String[] allowedExtensions =
{".gif", ".png", ".jpeg", ".jpg"};
for (int i = 0; i < allowedExtensions.Length; i++)
{
if (fileExtension == allowedExtensions[i])
{
fileOK = true;
}
}
}
if (fileOK)
{
try
{
FileUpload1.PostedFile.SaveAs(path
+ FileUpload1.FileName);
Label1.Text = "File uploaded!";
}
catch (Exception ex)
{
Label1.Text = "File could not be uploaded.";
}
}
else
{
Label1.Text = "Cannot accept files of this type.";
}
}
}