HttpResponse.Flush 方法
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
向客户端发送当前所有缓冲的输出。
public:
void Flush();
public void Flush ();
member this.Flush : unit -> unit
Public Sub Flush ()
例外
发送响应后刷新缓存。
示例
以下示例调用 Save 方法将 对象保存到 BitmapOutputStream 属性,并将图像转换为 JPEG 格式。 然后,代码对 Bitmap 对象和 Graphics 对象调用 Dispose
方法,释放它们使用的资源。 然后, Flush 它会调用 方法,将响应的内容发送到请求客户端。
有关完整示例,请参阅 HttpResponse 类。
<%@ Page Language="C#" %>
<%@ 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 void Page_Load(object sender, EventArgs e)
{
// <snippet2>
// 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;
// </snippet2>
// Create a font style.
Font rectangleFont = new Font(
"Arial", 10, FontStyle.Bold);
// Create integer variables.
int height = 100;
int width = 200;
// Create a random number generator and create
// variable values based on it.
Random r = new Random();
int x = r.Next(75);
int a = r.Next(155);
int x1 = r.Next(100);
// Create a bitmap and use it to create a
// Graphics object.
Bitmap bmp = new Bitmap(
width, height, PixelFormat.Format24bppRgb);
Graphics g = 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);
// <snippet3>
// 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();
// </snippet3>
}
</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>
<%@ 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)
' <snippet2>
' 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
' </snippet2>
' 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)
' <snippet3>
' 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()
' </snippet3>
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>
注解
强制将当前缓冲的所有输出发送到客户端。 在 Flush 请求处理期间,可以多次调用 方法。