How to Display an Image Stored as a BLOB in MySQL in a PictureBox?

How to Retrieve an Image from MySQL and Display it in a PictureBox

Problem:

Retrieving images stored as BLOBs in a MySQL database and displaying them in a PictureBox is not working correctly.

Solution:

The issue in the provided code lies in the incorrect retrieval of the image from the database. The following steps outline a method to retrieve and display images from a MySQL database:

1. Database Setup:

   • Create a table in the MySQL database with a column to store the image data as a BLOB type.

2. Display Image in PictureBox:

   • In the byteArrayToImage method, convert the byte array (ImageByte) to an Image object:

     public Image byteArrayToImage(byte[] byteArrayIn)
     {
         using (var ms = new MemoryStream(byteArrayIn))
         {
             return Image.FromStream(ms);
         }
     }

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   • In the photoLoad method, retrieve the image using a parameterized query:

     private void photoLoad()
     {
         // ...
         using (var con = new MySqlConnection(connectionString))
         {
             byte[] ImageByte = new byte[0];
             string query1 = "select image from reg.img_table where id= @id";
             using (var cmd = new MySqlCommand(query1, con))
             {
                 cmd.Parameters.AddWithValue("@id", Properties.Settings.Default.idImg);
                 
                 con.Open();
                 using (var row = cmd.ExecuteReader())
                 {
                     while (row.Read())
                     {
                         ImageByte = (byte[])(row["image"]);
                     }
                 }
             }
     
             if (ImageByte != null)
             {
                 // Convert to an Image object and display in PictureBox
                 roundPictureBox1.Image = byteArrayToImage(ImageByte);
                 roundPictureBox1.Refresh();
             }
         }
         // ...
     }

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3. Additional Considerations:

   • Ensure that the image is being saved correctly into the database (e.g., using File.ReadAllBytes to read the image file).
   • Check if the retrieved byte array (ImageByte) is not empty before attempting to convert it to an Image object.
   • Handle exceptions appropriately in the photoLoad method for error handling.

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