//保存照片数据 

public int SavePhoto(string photeFile)
    {
        //读取文件流
        FileStream fs = new FileStream(photeFile,FileMode.Open,FileAccess.Read);
        BinaryReader reader =new BinaryReader(fs);
        byte[] photo = reader.ReadBytes((int)fs.Length);
        reader.Close();
        fs.Close();
        string sql = "update student set zhaopian=@zhaopian where xuehao='001'";
        DataTable dt = new DataTable();
        SqlConnection conn = new SqlConnection();
        conn.ConnectionString = @"Data Source=(LocalDB)\v11.0;AttachDbFilename=|DataDirectory|\Database.mdf;Integrated Security=True";
        SqlCommand command = new SqlCommand(sql, conn);
        SqlParameter parm = new SqlParameter("@zhaopian", photo);
        command.Parameters.Add(parm);
        try
        {
            conn.Open();
            return command.ExecuteNonQuery();
        }
        catch (SqlException ex)
        {
            return -1;
        }
        finally
        {
            conn.Close();
        }
    }

//读取二进制数据 重新保存为新文件，新文件和旧文件大小相同

    public void ReadPhoto(string photeFile)
    {
        string sql = "select zhaopian from student where xuehao='001'";
        SqlConnection conn = new SqlConnection();
        conn.ConnectionString = @"Data Source=(LocalDB)\v11.0;AttachDbFilename=|DataDirectory|\Database.mdf;Integrated Security=True";
        SqlCommand command = new SqlCommand(sql,conn);
        try
        {
            conn.Open();
            SqlDataReader reader = command.ExecuteReader();
            while(reader.Read())
            {
                byte[] photo = reader[0] as byte[];
                FileStream fs = new FileStream(photeFile,FileMode.CreateNew);
                fs.Write(photo,0,photo.Length