读取数据库二进制图片后不能创建

Question

读取数据库图片后复制该图片的方法：
public void ReadPhoto(string photoFile)
    {
        string sql = "SELECT PHOTO FROM USERINFO WHERE UID=1";
        SqlConnection conn = new SqlConnection();
        conn.ConnectionString = "Server=.;database=Test;uid=sa;pwd=sa";
        SqlCommand cmd = new SqlCommand(sql, conn);
        try
        {
            conn.Open();
            SqlDataReader sdr = cmd.ExecuteReader();
            if (sdr.Read())
            {
                byte[] photo = sdr[0] as byte[];
                FileStream fs = new FileStream(photoFile, FileMode.CreateNew);
                fs.Write(photo, 0, photo.Length);
                fs.Close();
            }
            sdr.Close();
        }
        catch (Exception ex)
        {
            throw;
        }
        finally
        {
            conn.Close();
        }
    }protected void btnReadPhoto_Click(object sender, EventArgs e)
    {
        SQL sql = new SQL();
        sql.ReadPhoto(Server.MapPath("~/Images/aaa.jpg"));
    }
错误：aaa.jpg图片已经存在，删除之后再运行也是报存在的错误，请问是怎么回事？谢谢！

Answer 1

 string m_strPathName;//文件路径        string m_strConn = "data source=.;database=text.mdf;user id=sa;pwd=123456";  //连接数据库语句        private SqlConnection m_Conn = null;//数据库连接        private void OpenConn() //打开数据库
        {
             if (m_Conn == null)
            {
                m_Conn = new SqlConnection(m_strConn);
            }
            else if (m_Conn.State == ConnectionState.Closed)
            {
                m_Conn.Open();
            }
            
        }        private void CloseConn()//关闭数据库
        {
            if (m_Conn.State == ConnectionState.Open)
            {
                m_Conn.Close();
            }
        }        private void button1_Click(object sender, EventArgs e)
        {
            //实例化一个打开文件类
            using (OpenFileDialog openFiledDialog = new OpenFileDialog())
            {
                //设置初始目录
                openFiledDialog.InitialDirectory = "D:\\";
                //文件筛选
                openFiledDialog.Filter = "JPG文件|*.jpg|GIF文件|*.gif|PNG文件|*.PNG";
                //设置筛选的索引
                openFiledDialog.FilterIndex = 1;
                //弹出对话框
                if (openFiledDialog.ShowDialog() == DialogResult.OK)
                {                    
                    //获取文件完整路径
                    m_strPathName = openFiledDialog.FileName;
                    this.label1.Text = m_strPathName;
                    //从指定的路径创建文件
                    Image img = Image.FromFile(m_strPathName);
                    //设置为背景图片
                    this.pictureBox1.BackgroundImage = img;
                    this.pictureBox1.BackgroundImageLayout = ImageLayout.Stretch;
                  
                }
            }
        }
        private void button2_Click(object sender, EventArgs e)
        {
            try
            {                //将图像读入到字节数组
                FileStream fs = new FileStream(m_strPathName, FileMode.Open, FileAccess.Read);
                //将信息写入流中
                byte[] buffByte = new byte[fs.Length];
                fs.Read(buffByte, 0, (int)fs.Length);
                fs.Close();
                fs = null;                //建立Command命令,将信息写入数据库
                OpenConn();
                string strSQL = @"Insert into testdaxiang(infor,name) values(@img,@name)";
                SqlCommand comm = new SqlCommand(strSQL, m_Conn);
                //创建Parameter
                comm.Parameters.Add("@img", System.Data.SqlDbType.Image);
                comm.Parameters[0].Value = buffByte;
                comm.Parameters.Add("@name", System.Data.SqlDbType.VarChar);
                comm.Parameters[1].Value = m_strPathName.Substring(m_strPathName.LastIndexOf("\\") + 1);
               
                int nResult = comm.ExecuteNonQuery();
                if (nResult < 0)
                {
                    MessageBox.Show("保存失败××", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                    return;
                }
                else
                {
                    MessageBox.Show("保存成功……", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                }
                CloseConn();
                buffByte = null;
            }
            catch (Exception ee)
            {
                MessageBox.Show(ee.Message);
            }
        }        //返回一个图片信息
        private Image GetImageInf(string strSQL)
        {
            SqlCommand cmd = new SqlCommand(strSQL, m_Conn);
            SqlDataReader reader = cmd.ExecuteReader();
            reader.Read();
            MemoryStream buf = new MemoryStream((byte[])reader[0]);
            Image img = Image.FromStream(buf, true);
            return img;        }
    }