C# 5.0 Programmer's Reference

Chapter 20 ❘ 697
}
// Request the data stream.
Uri uri = new Uri(urlTextBox.Text);
Client = new WebClient();
Client.OpenReadCompleted += Client_OpenReadCompleted;
Client.OpenReadAsync(uri);
// Cancel the request.
private void cancelButton_Click(object sender, EventArgs e)
{
Client.CancelAsync();
}
// Process the stream.
private void Client_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
{
// See what the result was.
if (e.Error != null)
{
MessageBox.Show(e.Error.Message);
}
else if (e.Cancelled)
{
MessageBox.Show("Canceled");
}
else
{
// Get the data from the stream.
// (You must close the stream when finished.)
using (Stream stream = e.Result)
{
// Use the stream to create a Bitmap.
Bitmap bitmap = new Bitmap(stream);
}
}
// Display the result.
imagePictureBox.Image = bitmap;
}
// Make the form big enough.
Size size = new Size(
Math.Max(imagePictureBox.Right + 12, ClientSize.Width),
Math.Max(imagePictureBox.Bottom + 12, ClientSize.Height));
ClientSize = size;
7. The DownloadData example program uses the following code to do this.
using (WebClient client = new WebClient())
{
byte[] bytes = client.DownloadData(urlTextBox.Text);
// Make a stream associated with the bytes.
using (MemoryStream stream = new MemoryStream(bytes))
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