在UpPhoto.aspx文件中添加如下:
<input id="UpPhoto" name="UpPhoto" runat="server" type="file">
<asp:Button id="btnAdd" name="btnAdd" runat="server" Text="上传"></asp:Button>

然后在后置代码文件UpPhoto.aspx.cs添加btnAdd按钮的单击事件处理代码:
private void btnAdd_Click(object sender, System.EventArgs e)
{
        //获得图象并把图象转换为byte[]
        HttpPostedFile upPhoto=UpPhoto.PostedFile;
        int upPhotoLength=upPhoto.ContentLength;
        byte[] PhotoArray=new Byte[upPhotoLength];
        Stream PhotoStream=upPhoto.InputStream;
        PhotoStream.Read(PhotoArray,0,upPhotoLength);

        //连接数据库
        SqlConnection conn=new SqlConnection();
        conn.ConnectionString="Data Source=localhost;Database=test;User Id=sa;Pwd=sa";

        SqlCommand cmd=new SqlCommand("UpdateImage",conn);
        cmd.CommandType=CommandType.StoredProcedure;

        cmd.Parameters.Add("@UpdateImage",SqlDbType.Image);
        cmd.Parameters["@UpdateImage"].Value=PhotoArray;

        //如果你希望不使用存储过程来添加图片把上面四句代码改为：
        //string strSql="Insert into test(FImage) values(@FImage)";
        //SqlCommand cmd=new SqlCommand(strSql,conn);
        //cmd.Parameters.Add("@FImage",SqlDbType.Image);
        //cmd.Parameters["@FImage"].Value=PhotoArray;

 conn.Open();
 cmd.ExecuteNonQuery();
 conn.Close();
}

二，从SqlServer中读取并显示出来
在需要显示图片的地方添加如下代码:
<asp:image id="imgPhoto" runat="server" ImageUrl="ShowPhoto.aspx"></asp:image>

ShowPhoto.aspx主体代码：
private void Page_Load(object sender, System.EventArgs e)
{
     if(!Page.IsPostBack)
     {
                SqlConnection conn=new SqlConnection()
                conn.ConnectionString="Data Source=localhost;Database=test;User Id=sa;Pwd=sa";
               
                string strSql="select * from test where id=2";//这里假设获取id为2的图片
                SqlCommand cmd=new SqlCommand()
                reader.Read();
                Response.ContentType="application/octet-stream";
                Response.BinaryWrite((Byte[])reader["FImage"]);
                Response.End();
                reader.Close();
     }
}