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.
