Question

我有一项任务是上传图片并将Gridview绑定到显示图片。

我正在使用Generic Handler并且抛出以下错误：“类型HttpHandler不会继承'System.web.IHttpHandler''的形式。”

任何人都可以帮忙。

我的代码：HttpHandler.ashx

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

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

public class HTTPHandler  { //IHttpHandler {

    string strcon = ConfigurationManager.AppSettings["ImagConnectionString2"].ToString();

    public void ProcessRequest (HttpContext context) {
        string imageid = context.Request.QueryString["ImageId"];
        SqlConnection connection = new SqlConnection(strcon);
        connection.Open();
        SqlCommand command = new SqlCommand("select Image from image where ImageId=" + imageid, connection);
        SqlDataReader dr = command.ExecuteReader();
        dr.Read();
        context.Response.BinaryWrite((Byte[])dr[0]);
        connection.Close();
        context.Response.End();
    }
}

我的代码：Button_Click

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.Web.Configuration;
using System.Configuration;
using System.Data;
using System.Data.SqlTypes;

public partial class _Default : Page
{
    string strcon = ConfigurationManager.ConnectionStrings["ImagConnectionString2"].ConnectionString;

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            BindGridData();
        }
    }

    protected void btnUpload_Click(object sender, EventArgs e)
    {
        if (fileuploadImage.HasFile)
        {
            int length = fileuploadImage.PostedFile.ContentLength;

            //create a byte array to store the binary image data
            byte[] imgbyte = new byte[length];

            //store the currently selected file in memeory
            HttpPostedFile img = fileuploadImage.PostedFile;

            //set the binary data
            img.InputStream.Read(imgbyte, 0, length);
            string imagename = txtImageName.Text;

            //use the web.config to store the connection string
            SqlConnection connection = new SqlConnection(strcon);
            connection.Open();

            SqlCommand cmd = new SqlCommand("INSERT INTO image (ImageName,Image) VALUES (@imagename,@imagedata)", connection);
            cmd.Parameters.Add("@imagename", SqlDbType.VarChar, 50).Value = imagename;
            cmd.Parameters.Add("@imagedata", SqlDbType.Image).Value = imgbyte;
            int count = cmd.ExecuteNonQuery();

            connection.Close();
            if (count == 1)
            {
                BindGridData();
                txtImageName.Text = string.Empty;

                ScriptManager.RegisterStartupScript(this, this.GetType(), "alertmessage", "javascript:alert('" + imagename + " image inserted successfully')", true);
            }
        }

    }

    private void BindGridData()
    {
        SqlConnection connection = new SqlConnection(strcon);
        SqlCommand command = new SqlCommand("SELECT imagename,ImageID from [image]", connection);
        SqlDataAdapter daimages = new SqlDataAdapter(command);
        DataTable dt = new DataTable();
        daimages.Fill(dt);
        gvImages.DataSource = dt;
        gvImages.DataBind();
        gvImages.Attributes.Add("bordercolor", "black");

    }
}

Answer 1

创建客户处理程序时，仍然需要继承接口。请尝试继承“IHttpHandler”类：

public class HTTPHandler : IHttpHandler

我试图上传图片并绑定Gridview来显示图片？

1 个答案: