HttpResponse.Flush Method ()

 

Sends all currently buffered output to the client.

Namespace:   System.Web
Assembly:  System.Web (in System.Web.dll)

Public Sub Flush

Exception Condition
HttpException

The cache is flushed after the response has been sent.

Forces all currently buffered output to be sent to the client. The Flush method can be called multiple times during request processing.

The following example calls the Save method to save a Bitmap object to the OutputStream property and converts the image to the JPEG format. The code then calls the Dispose method on the Bitmap object and a Graphics object, releasing the resources that they were using. It then calls the Flush method to send the content of the response to the requesting client.

For a complete example, see the HttpResponse class.

<%@ Page Language="VB" %>
<%@ import Namespace="System.Drawing" %>
<%@ import Namespace="System.Drawing.Imaging" %>
<%@ import Namespace="System.Drawing.Drawing2D" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

   Private Sub Page_Load(sender As Object, e As EventArgs)
      ' Set the page's content type to JPEG files
      ' and clears all content output from the buffer stream.
      Response.ContentType = "image/jpeg"
      Response.Clear()

      ' Buffer response so that page is sent
      ' after processing is complete.
      Response.BufferOutput = True

      ' Create a font style.
      Dim rectangleFont As New Font( _
          "Arial", 10, FontStyle.Bold)

      ' Create integer variables.
      Dim height As Integer = 100
      Dim width As Integer = 200

      ' Create a random number generator and create
      ' variable values based on it.
      Dim r As New Random()
      Dim x As Integer = r.Next(75)
      Dim a As Integer = r.Next(155)
      Dim x1 As Integer = r.Next(100)

      ' Create a bitmap and use it to create a
      ' Graphics object.
      Dim bmp As New Bitmap( _
          width, height, PixelFormat.Format24bppRgb)
      Dim g As Graphics = Graphics.FromImage(bmp)

      g.SmoothingMode = SmoothingMode.AntiAlias
      g.Clear(Color.LightGray)

      ' Use the Graphics object to draw three rectangles.
      g.DrawRectangle(Pens.White, 1, 1, width - 3, height - 3)
      g.DrawRectangle(Pens.Aquamarine, 2, 2, width - 3, height - 3)
      g.DrawRectangle(Pens.Black, 0, 0, width, height)

      ' Use the Graphics object to write a string
      ' on the rectangles.
      g.DrawString("ASP.NET Samples", rectangleFont, SystemBrushes.WindowText, New PointF(10, 40))

      ' Apply color to two of the rectangles.
      g.FillRectangle( _
          New SolidBrush( _
              Color.FromArgb(a, 255, 128, 255)), _
          x, 20, 100, 50)

      g.FillRectangle( _
          New LinearGradientBrush( _
              New Point(x, 10), _
              New Point(x1 + 75, 50 + 30), _
              Color.FromArgb(128, 0, 0, 128), _
              Color.FromArgb(255, 255, 255, 240)), _
          x1, 50, 75, 30)

      ' Save the bitmap to the response stream and
      ' convert it to JPEG format.
      bmp.Save(Response.OutputStream, ImageFormat.Jpeg)

      ' Release memory used by the Graphics object
      ' and the bitmap.
      g.Dispose()
      bmp.Dispose()

      ' Send the output to the client.
      Response.Flush()
   End Sub 'Page_Load

</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="form1" runat="server">
    </form>
</body>
</html>

.NET Framework
Available since 1.1
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