二进制格式图片显示

最新推荐文章于 2024-05-07 20:51:16 发布

原创最新推荐文章于 2024-05-07 20:51:16 发布 · 1k 阅读

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文章标签：

#buffer #stream #byte #image #server

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两张方式获取数据库的二进制图片

1、用aspx 的Page_Load事件获取；（适用于单张图片显示）

2、用ashx类 一般处理事件 获取；（适用于一组图片显示）

显示图片的网页：

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default4.aspx.cs" Inherits="Default4" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
       <table>
          <tr><td>aspx方式显示图片</td></tr>
          <tr>
          
             <td>
                <asp:Image ID="image1" Width="100" Height="100" runat="server" ImageUrl="Default5.aspx" /> 
             </td>
          </tr>
          <tr><td>ashx方式显示图片</td></tr>
          <tr>
          
             <td>
                <asp:Image ID="image2" runat="server" Width="100" Height="100" ImageUrl="Getimg.ashx" /> 
             </td>
          </tr>
       </table>
    </div>
    </form>
</body>
</html>

1、获取图片的网页

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Text;

public partial class Default5 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        
        string conSql = "";
        SqlConnection conn = new SqlConnection(conSql);

        SqlCommand com = new SqlCommand();
        com.Connection = conn;

        StringBuilder comText = new StringBuilder();
        comText.Append("select ImageCol from Image_Table");
        com.CommandText = comText.ToString();

        conn.Open();

        byte[] file = (byte[])com.ExecuteScalar();
        System.IO.MemoryStream stream = null;
        try
        {

            Response.ContentType = "image/jpeg";
            stream = new System.IO.MemoryStream(file);

            int buffersize = 1024 * 16;
            byte[] buffer = new byte[buffersize];
            int conentsize = stream.Read(buffer, 0, buffersize);

            while (conentsize > 0)
            {
                //将缓冲区的输入输出到页面

                Response.OutputStream.Write(buffer, 0, conentsize);
                conentsize = stream.Read(buffer, 0, buffersize);
            }

        }
        catch
        {
        }
        finally
        {
            if (stream != null)
                stream.Close();
        }
    }

}

2、获取图片的ashx类

<%@ WebHandler Language="C#" Class="Getimg" %>

using System;
using System.Web;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;

public class Getimg : IHttpHandler {

    public void ProcessRequest(HttpContext context)
    {
        string conSql = "";
        SqlConnection conn = new SqlConnection(conSql);

        SqlCommand com = new SqlCommand();
        com.Connection = conn;

        System.Text.StringBuilder comText = new System.Text.StringBuilder();
        comText.Append("select ImageCol from Image_Table");
        com.CommandText = comText.ToString();

        conn.Open();
        SqlDataReader dr = com.ExecuteReader();
        System.IO.MemoryStream stream = null;
        if (dr.Read())
        {
            byte[] file = (byte[])dr["ImageCol"];
            context.Response.ContentType = "image/jpeg";
            stream = new System.IO.MemoryStream(file);

            int buffersize = 1024 * 16;
            byte[] buffer = new byte[buffersize];
            int conentsize = stream.Read(buffer, 0, buffersize);

            while (conentsize > 0)
            {
                context.Response.OutputStream.Write(buffer, 0, conentsize);
                conentsize = stream.Read(buffer, 0, buffersize);
            }
        }
        dr.Close();
    }

public bool IsReusable {
       get {
         return false;
       }
}
}