关于此类的介绍:查看HttpResponse


定义:

封装来自 ASP.NET 操作的 HTTP 响应信息。

属性:

ResponseEntity自定义code response属性_HTTP

建议使用第二个。

下面的示例将响应的 ContentType 属性设置为 image/jpeg,调用 Clear 方法以移除可能附加到响应的其他内容,然后将 BufferOutput 属性设置为 true,这样就可以在将任何内容发送到请求客户端之前先处理整个页。

 

 

ResponseEntity自定义code response属性_缓存_02

ResponseEntity自定义code response属性_HTTP_03

HttpCachePolicy 类



包含可用于设置特定于缓存的 HTTP 标头以及用于控制 ASP.NET 页输出缓存的方法。

HTTP头允许客户端和服务器通过请求或响应传递附加信息。 点击查看标头

属性:

ResponseEntity自定义code response属性_验证码_04

 

方法:


 

ResponseEntity自定义code response属性_验证码_05

ResponseEntity自定义code response属性_HTTP_06

ResponseEntity自定义code response属性_验证码_07

 

 

 

ResponseEntity自定义code response属性_缓存_08

HttpCacheability 枚举



提供用于设置的枚举的值 Cache-Control HTTP 标头。



ResponseEntity自定义code response属性_验证码_09

 

 

 

ResponseEntity自定义code response属性_缓存_10

MIME类型介绍:点击查看

 MIME类型的机理是告诉客户端传输的各种文件:文件名的扩展具有在网络上没有任何意义。因此,正确设置服务器是非常重要的,因此每个文档都会传送正确的MIME类型。浏览器通常使用MIME类型来确定在获取资源时要执行的默认操作。

常用类型:

text/plain   文本文件

image/图片类型   一般传输图片

application/octet-stream    二进制数据 (常用来下载)

 

 

 

ResponseEntity自定义code response属性_验证码_11

 

ResponseEntity自定义code response属性_缓存_12

 

 

ResponseEntity自定义code response属性_HTTP_13

ResponseEntity自定义code response属性_缓存_14

 



<div>
        <asp:TextBox ID="txtTest" runat="server" TextMode="MultiLine"></asp:TextBox>

        <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Button" />
    </div>



 



Server.UrlEncode(txtTest.Text,Response.Output);



 

ResponseEntity自定义code response属性_验证码_15

 

 

ResponseEntity自定义code response属性_HTTP_16

ResponseEntity自定义code response属性_HTTP_17

这个等下看一个列子

 

 

ResponseEntity自定义code response属性_缓存_18



HttpCookie MyCookie = new HttpCookie("LastVisit");
 MyCookie.Value = DateTime.Now.ToString();
 Response.AppendCookie(MyCookie);



 

 

ResponseEntity自定义code response属性_验证码_19

ResponseEntity自定义code response属性_缓存_20

备注:如果您使用 AppendHeader 方法发送缓存特定的标头并在同一时间使用的缓存对象模型 (Cache) 来设置与缓存相关的 HTTP 响应标头的缓存策略 (Cache-Control, ,Expires, ,Last-Modified, ,Pragma, ,和 Vary) 时使用的缓存对象模型可能会删除。 如果一个用户控件设置的标头"Cache-Control: Public"和另一个用户控件设置的限制性更强的标头"Cache-Control: Private"通过调用 SetCacheability, ,则"Cache-Control: Private"标头将随响应一起发送。

 



Response.AppendHeader("CustomAspNetHeader", "Value1");



例如:



//   Response.AppendHeader("contentType", "text/html; charset=utf-8");
            Response.ContentType = "text/html;charSet=utf-8";



这两句代码代表一个意思。

 

 

 

 

 

 

ResponseEntity自定义code response属性_验证码_21

ResponseEntity自定义code response属性_缓存_22



FileStream MyFileStream;
            long FileSize;
            MyFileStream = new FileStream(Server.MapPath("../待了解.txt"), FileMode.Open);
            FileSize = MyFileStream.Length;

            byte[] Buffer = new byte[(int)FileSize];
            MyFileStream.Read(Buffer, 0, (int)FileSize);
            MyFileStream.Close();

            Response.ContentType = "application/octet-stream"; //可以控制类型
            Response.ClearContent();
            Response.Write("<b>File Contents: </b>");
            Response.BinaryWrite(Buffer);



一运行就会下载。

 

 

ResponseEntity自定义code response属性_HTTP_23

ResponseEntity自定义code response属性_验证码_24

ResponseEntity自定义code response属性_HTTP_25

 

 

ResponseEntity自定义code response属性_HTTP_26



char[] charArray = {'H', 'e', 'l', 'l', 'o', ',', ' ',
                       'w', 'o', 'r', 'l', 'd'};

            // Write a character array to the client.
            Response.Write(charArray, 0, charArray.Length);

            // Write a single characher.
            Response.Write(';');

            // Write a sub-section of a character array to the client.
            Response.Write(charArray, 0, 5);
            // Write an object to the client.
            object obj = (object)13;
            Response.Write(obj);



ResponseEntity自定义code response属性_缓存_27

 

 

 

ResponseEntity自定义code response属性_验证码_28



protected void Page_Load(object sender, EventArgs e)
        {
            String FileName;
            FileInfo MyFileInfo;
            long StartPos = 0, FileSize;

            FileName = Server.MapPath("../待了解.txt");
            MyFileInfo = new FileInfo(FileName);
            FileSize = MyFileInfo.Length;

            Response.Write("Please Login: <br>");
            Response.WriteFile(FileName, StartPos, FileSize);
        }



 

 

 

ResponseEntity自定义code response属性_HTTP_29

这个跟上面一样的。

 

 

 

用这个类很常见就是生成验证码,和下载文件。

验证码:



//创建画布
            int codeW = 80;
            int codeH = 22;
            int fontSize = 16;
            string chkCode = string.Empty;
            //颜色列表,用于验证码、噪线、噪点 
            Color[] color = { Color.Black, Color.Red, Color.Blue, Color.Green, Color.Orange, Color.Brown, Color.Brown, Color.DarkBlue };
            //字体列表,用于验证码 
            string[] font = { "Times New Roman", "Verdana", "Arial", "Gungsuh", "Impact" };
            //验证码的字符集,去掉了一些容易混淆的字符 
            char[] character = { '2', '3', '4', '5', '6', '8', '9', 'a', 'b', 'd', 'e', 'f', 'h', 'k', 'm', 'n', 'r', 'x', 'y', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'R', 'S', 'T', 'W', 'X', 'Y' };
            Random rnd = new Random();
            //生成验证码字符串 
            for (int i = 0; i < 4; i++)
            {
                chkCode += character[rnd.Next(character.Length)];
            }
            //写入Session

            //创建画布
            Bitmap bmp = new Bitmap(codeW, codeH);
            Graphics g = Graphics.FromImage(bmp);
            g.Clear(Color.White);
            //画噪线 
            for (int i = 0; i < 1; i++)
            {
                int x1 = rnd.Next(codeW);
                int y1 = rnd.Next(codeH);
                int x2 = rnd.Next(codeW);
                int y2 = rnd.Next(codeH);
                Color clr = color[rnd.Next(color.Length)];
                g.DrawLine(new Pen(clr), x1, y1, x2, y2);
            }
            //画验证码字符串 
            for (int i = 0; i < chkCode.Length; i++)
            {
                string fnt = font[rnd.Next(font.Length)];
                Font ft = new Font(fnt, fontSize);
                Color clr = color[rnd.Next(color.Length)];
                g.DrawString(chkCode[i].ToString(), ft, new SolidBrush(clr), (float)i * 18 + 2, (float)0);
            }
            //画噪点 
            for (int i = 0; i < 100; i++)
            {
                int x = rnd.Next(bmp.Width);
                int y = rnd.Next(bmp.Height);
                Color clr = color[rnd.Next(color.Length)];
                bmp.SetPixel(x, y, clr);
            }


            //清除缓存,设置改页面无缓存
            Response.BufferOutput = true;
            Response.ExpiresAbsolute = System.DateTime.Now.AddMilliseconds(0);
            Response.Expires = 0;
            Response.CacheControl = "no-cache";
            Response.AppendHeader("Pragma", "No-Cache");


            //第一种
            Response.ContentType = "image/png";
            Response.ClearContent();
            bmp.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Png);

            bmp.Dispose();
            g.Dispose();

            //第二种
            //MemoryStream ms = new MemoryStream();
            //try
            //{
            //    bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Png);//把画布以什么格式保存流
            //    //你要告诉客户端是什么类型
            //    Response.ContentType = "image/png";
            //    Response.ClearContent();
            //    Response.BinaryWrite(ms.ToArray());
            //}
            //finally
            //{
            //    //释放资源
            //    bmp.Dispose();
            //    g.Dispose();
            //}



 

下载案例:



FileStream MyFileStream;
            long FileSize;
            MyFileStream = new FileStream(Server.MapPath("../待了解.txt"), FileMode.Open);
            FileSize = MyFileStream.Length;

            byte[] Buffer = new byte[(int)FileSize];
            MyFileStream.Read(Buffer, 0, (int)FileSize);
            MyFileStream.Close();

            //一定需要设置的,附件下载的标头
            Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode("测试.txt"));
            Response.ContentType = "application/octet-stream";  //设置了标头这个可以不用设置 
            Response.ClearContent();
            Response.BinaryWrite(Buffer);
            Response.Flush();
            Response.End();