Question

在ASP.NET中怎么图片转换二进制

Answer 1

首先数据库里面有一字段类型为image,我这里是一个窗体应用程序，也是将图片以二进制的形式保存至数据库的，思路是一样的

byte[] photo;

        public byte[] Photo
        {
            get { return photo; }
            set { photo = value; }
        }

        FileStream fs;
        string fileName = string.Empty;

        private void btnChooose_Click(object sender, EventArgs e)
        {
            OpenFileDialog fileDialog = new OpenFileDialog();
            fileDialog.Filter = "*.jpg|*.jpg|*.gif|*.gif|*.bmp|*.bmp";
            if (fileDialog.ShowDialog() == DialogResult.OK)
            {
                fileName = fileDialog.FileName;
                fs = new FileStream(fileName, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite);
                pictureBox.Image = Image.FromStream(fs);
                fs.Close();
            }
        }

        private void btnSave_Click(object sender, EventArgs e)
        {
            if (!string.IsNullOrEmpty(fileName))
            {
                fs = new FileStream(fileName, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite);
                byte[] imageByte = new byte[fs.Length];
                fs.Read(imageByte, 0, (int)fs.Length);
                Photo = imageByte;
                fs.Close();
                AddImage();
            }
            else
            {
                MessageBox.Show("请选择图片");
            }
        }

        private void AddImage()
        {
            using (SqlConnection connection = new SqlConnection(connString))
            {
                connection.Open();
                SqlCommand command = new SqlCommand("PROC_ADDIMAGE", connection);
                command.CommandType = CommandType.StoredProcedure;
                command.Parameters.Add("@IMAGE", SqlDbType.Image).Value = Photo;
               int rows =  command.ExecuteNonQuery();
               if (rows > 0)
               {
                   MessageBox.Show("添加成功");
               }
               else
               {
                   MessageBox.Show("添加失败");
               }
            }
        }

        private void Form1_Load(object sender, EventArgs e)
        {
        }

        int index;
        /// <summary>
        /// 获取图片
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnGetImage_Click(object sender, EventArgs e)
        {
            /// <summary>
            /// 存图片的集合
            /// </summary>
            IList<Form1> form1List = new List<Form1>();

            using (SqlConnection conn = new SqlConnection(connString))
            {
                conn.Open();
                SqlCommand command = new SqlCommand("PROC_GETIMAGE", conn);
                command.CommandType = CommandType.StoredProcedure;
                using (SqlDataReader reader = command.ExecuteReader())
                {
                    while (reader.Read())
                    {
                        Form1 form1 = new Form1();
                        form1.Photo = (byte[])reader["Photo"];
                        form1List.Add(form1);
                    }
                }
            }

            if (form1List.Count == 1)
            {
                MemoryStream imageStream = new MemoryStream(form1List[0].Photo);
                pictureBox.Image = Image.FromStream(imageStream);
            }
            else if (form1List.Count > 1)
            {
                index++;
                if (index < form1List.Count)
                {
                  
                    btnGetImage.Text = "下一张";
                    MemoryStream imageStream = new MemoryStream(form1List[index].Photo);
                    pictureBox.Image = Image.FromStream(imageStream);
                }
                else
                {
                    index=0;
                    MemoryStream imageStream = new MemoryStream(form1List[index].Photo);
                    pictureBox.Image = Image.FromStream(imageStream);
                }
                
            }
            else
            {
                MessageBox.Show("存中还没有图片");
            }
        }

        /// <summary>
        /// 清除图片
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnClear_Click(object sender, EventArgs e)
        {
            pictureBox.Image = null;
        }