C＃：当我尝试将System.Drawing.Image保存到MemoryStream时抛出错误

Question

I am taking some (jpeg) images with a camera and inserting them to the database (as a blob). In order to insert them to the database, I have to pass the image in a byte array.

Here is a little code that does the conversion to the byte array:

public static byte[] JpegToByteArray(System.Drawing.Image imageIn)
    {                        
       MemoryStream ms = new MemoryStream();
       imageIn.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg); //PROBLEM IS HERE!
       return  ms.ToArray();
    }

Although, I am sure that the image I pass is in jpeg format, "imageIn.Save(...)" throws an error as follows:

Here is the definition of saving method:

    public void Save(Stream stream, ImageFormat format);
    //
    // Summary:
    //     Saves this System.Drawing.Image to the specified file in the specified format.
    //
    // Parameters:
    //   filename:
    //     A string that contains the name of the file to which to save this System.Drawing.Image.
    //
    //   format:
    //     The System.Drawing.Imaging.ImageFormat for this System.Drawing.Image.
    //
    // Exceptions:
    //   System.ArgumentNullException:
    //     filename or format is null.
    //
    //   System.Runtime.InteropServices.ExternalException:
    //     The image was saved with the wrong image format.-or- The image was saved
    //     to the same file it was created from.

The image(s) I retrieve and pass to the function are never stored to/read from the file system. After I insert the image to the database, I dispose it. And the method that I retrieve images just returns a list of System.Drawing.Image (with 4 elements). There is nothing special about it.

Do you guys have any idea why this might happen?

Thanks for your time.

EDIT:

I am able to set the images to the picturebox, for example:

pictureBox1.Image = imageIn;
picturebox.Refresh();

But, cannot save the images neither to MemoryStream, nor to the file system.

Answer 1

Try this-

    public static void PerisitImage(string path, IDbConnection connection)
{
    using (var command = connection.CreateCommand ())
    {
        Image img = Image.FromFile (path);
        MemoryStream tmpStream = new MemoryStream();
        img.Save (tmpStream, ImageFormat.Png); // change to other format
        tmpStream.Seek (0, SeekOrigin.Begin);
        byte[] imgBytes = new byte[MAX_IMG_SIZE];
        tmpStream.Read (imgBytes, 0, MAX_IMG_SIZE);

        command.CommandText = "INSERT INTO images(payload) VALUES (:payload)";
        IDataParameter par = command.CreateParameter();
        par.ParameterName = "payload";
        par.DbType = DbType.Binary;
        par.Value = imgBytes;
        command.Parameters.Add(par);
        command.ExecuteNonQuery ();
    }
}

Source- How to save image in database using C#