File upload

In this article, I will discuss how you can create your own File Upload feature in a Silverlight

application.

Step 1:

First, create a Silverlight Web application in Visual Studio 2008. You will see your default

Page.xaml.

Step 2:

On Create Page.xaml, change your code by adding following Panel, Button, and TextBlock

controls.

On buttin click event handler, I write code to call the OpenFileDialog that allows us to browse files

and gives us the selected file name. Here is the code.

public void

Button_Click(object sender, RoutedEventArgs e)

{

OpenFileDialog

dlg = new OpenFileDialog();

dlg.Multiselect =

false;

dlg.Filter =

"All files (*.*)|*.*|PNG Images (*.png)|*.png";

bool

? retval = dlg.ShowDialog();

if

(retval != null && retval == true)

{

UploadFile(dlg.File.Name, dlg.File.OpenRead());

StatusText.Text = dlg.File.Name;

}

else

{

StatusText.Text =

"No file selected...";

}

}

As you can see from the above code, I call a method UploadFile by passing the selected file name

from the OpenFileDialog.

The

UploadFile method looks like following. In this code, I use a WebClient class and a PushData

method.

private

void UploadFile(string fileName, Stream data)

{

UriBuilder

ub = new UriBuilder("http://localhost:3840/receiver.ashx");

ub.Query = string.Format(

"filename={0}", fileName);

WebClient

c = new WebClient();

c.OpenWriteCompleted += (sender, e) =>

{

PushData(data, e.Result);

e.Result.Close();

data.Close();

};

c.OpenWriteAsync(ub.Uri);

}

private void PushData(

Stream input, Stream output)

{

byte[] buffer = new byte[4096];

int bytesRead;

while ((bytesRead = input.Read(buffer, 0, buffer.Length)) != 0)

{

output.Write(buffer, 0, bytesRead);

}

}

Step 3:

Add a new Generic Handler receiver.ashx.

Now let's add a class. Right click on the project and Add a new item by selecting Generic Handler in

the right side templates as shown below.

And add the following code on the coe behind:

<%@

WebHandler Language="C#" Class="receiver" %>

using System;

using System.Web;

using System.IO;

public class

receiver : IHttpHandler {

public void ProcessRequest (

HttpContext context) {

string filename = context.Request.QueryString[

"filename"].ToString();

using (

FileStream fs = File.Create(context.Server.MapPath("~/App_Data/" + filename)))

{

SaveFile(context.Request.InputStream, fs);

}

}

private void SaveFile(

Stream stream, FileStream fs)

{

byte[] buffer = new byte[4096];

int bytesRead;

while ((bytesRead = stream.Read(buffer, 0, buffer.Length)) != 0)

{

fs.Write(buffer, 0, bytesRead);

}

}

public bool IsReusable {

get {

return false;

}

}

}

Step 4:

Build and Run

That's all. You are done. Now just build and run your project.