从MySQL数据库获取图像 – C＃

我必须在MySQL数据库中存储和恢复图像。 为此，我使用了本页面给出的说明： MySQL论坛 ，我可以通过以下代码成功存储Image：

SaveIamge：

void SaveImage() { MemoryStream ms = new MemoryStream(); pictureBox1.Image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg); cmd = new MySqlCommand("INSERT INTO " + tableName + " ( Product, Manufacturer, Description, Price, Image) Values ('New_Product', 'New_Manufacturer', 'New_Description', '0', @Image)", conn); cmd.Parameters.Add(new MySqlParameter("@Image", Convert.ToBase64String(ms.ToArray()))); cmd.ExecuteNonQuery(); } 

但我无法从数据库中获取图像：我正在使用以下代码，请检查这里有什么问题：

GetThumbnail：

  void GetThumbnail() { string TN = tableNames[comboBox1.SelectedIndex]; cmd = new MySqlCommand("SELECT Image FROM " + tableName + " WHERE Product = " + ProductTitle(), conn); object imgObj = cmd.ExecuteScalar(); byte[] b = Convert.FromBase64String(Convert.ToString(imgObj)); MemoryStream ms = new MemoryStream(b); pictureBox2.Image = Image.FromStream(ms); } 

Answer 1

如何将图像存储到二进制字段？ 它比Base64编码更有意义：

 void SaveImage(byte[] image) { using (var conn = new MySqlConnection(ConnectionString)) using (var cmd = conn.CreateCommand()) { cmd.CommandText = "INSERT INTO pictures (Product, Manufacturer, Description, Price, Image) VALUES ('New_Product', 'New_Manufacturer', 'New_Description', '0', ?Image)"; cmd.Parameters.Add("?Image", image); cmd.ExecuteNonQuery(); } } byte[] GetImage(string product) { using (var conn = new MySqlConnection(ConnectionString)) using (var cmd = conn.CreateCommand()) { cmd.CommandText = "SELECT Image FROM pictures WHERE Product = ?product"; cmd.Parameters.Add("?product", product); using (var reader = cmd.ExecuteReader()) { if (!reader.Read()) { return null; } const int CHUNK_SIZE = 2 * 1024; byte[] buffer = new byte[CHUNK_SIZE]; long bytesRead; long fieldOffset = 0; using (var stream = new MemoryStream()) { while ((bytesRead = reader.GetBytes(reader.GetOrdinal("Image"), fieldOffset, buffer, 0, buffer.Length)) > 0) { stream.Write(buffer, 0, (int)bytesRead); fieldOffset += bytesRead; } return stream.ToArray(); } } } } 

然后：

 using (var ms = new MemoryStream()) { pictureBox1.Image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg); SaveImage(ms.ToArray()); } 

当你想要检索：

 byte[] image = GetImage("New_Product"); MemoryStream stream = new MemoryStream(image); pictureBox2.Image = Image.FromStream(ms);