Uploading Text File with OpenWriteAsync

Hello,

My site needs to read some files, do string replacements, and save the files with a new name. To start I am trying a simple example with text files using System.Net.WebClient. The folder for input and output files is /Docs/Cust under my site root folder.

The read (using OpenReadAsync) works fine. The OpenWriteAsync does not write the file and also does not return an error. Fiddler doesn't show a problem either.

I'm using a handler in my web project and the Uri to the handler and output file name is in the call to OpenWriteAsync.

Here is the code calling OpenWriteAsync

Code:

            
Dim client as WebClient
Dim sFileName As String = "Modified.txt"
Dim fileContent As Byte() = System.Text.Encoding.UTF8.GetBytes(ModifiedText)

AddHandler client.OpenWriteCompleted, AddressOf Client_OpenWriteCompleted
Dim u As New Uri(Application.Current.Host.Source, "../WebServices/FileUpload.ashx/?filename=" & sFileName)
client.OpenWriteAsync(u, Nothing, fileContent)

Here's the callback from OpenWriteAsync:

Code:

    Private Sub Client_OpenWriteCompleted(ByVal sender As Object, ByVal e As OpenWriteCompletedEventArgs)

        Try
            If e.Error IsNot Nothing Then
                MessageBox.Show("OpenWriteAsync Error: " & e.Error.ToString)
            End If
            Dim fileContent As Byte() = TryCast(e.UserState, Byte())
            Dim outputStream As Stream = e.Result
            outputStream.Write(fileContent, 0, fileContent.Length)
            outputStream.Close()

            MessageBox.Show("Write Completed")

        Catch ex As Exception
            MessageBox.Show("Client_OpenWriteCompleted: " & ex.Message.ToString)
        End Try

    End Sub

In my webconfig I made my application full trust and also set a location tag for the destination folder as follows:

Code:

  <location path="Cust">
    <system.webServer>
      <security>
        <authorization>
          <add accessType="Allow" users="*" />
        </authorization>
      </security>
    </system.webServer>
  </location>

Obviously I don't want to use the "*" except for testing purposes.

If anyone has a suggestion concerning why the output file doesn't get created, that would be most appreciated!

Randy

 

Solved it...

The code uses a generic handler (FileUplod.ashx) that implements IHttpHandler. This requires an IsReusable property and a ProcessRequest method.

In VB.NET the the procedure and property must also have an implements keyword:

Code:

    Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest

I guess that in C# adding implements to the class definition is enough.

Anyway, its working...

 

Glad it's working for you, thanks for the follow-up.