| public GetBytes ( int i, long fieldOffset, byte buffer, int bufferoffset, int length ) : long | ||
| i | int | The zero-based column ordinal. |
| fieldOffset | long | The index within the field from which to begin the read operation. |
| buffer | byte | The buffer into which to read the stream of bytes. |
| bufferoffset | int | The index for buffer to begin the read operation. |
| length | int | The maximum length to copy into the buffer. |
| return | long | |
public override long GetBytes(int i, long fieldOffset, byte[] buffer, int bufferoffset, int length)
{
if (i >= FieldCount)
Throw(new IndexOutOfRangeException());
IMySqlValue val = GetFieldValue(i, false);
if (!(val is MySqlBinary) && !(val is MySqlGuid))
Throw(new MySqlException("GetBytes can only be called on binary or guid columns"));
byte[] bytes = null;
if (val is MySqlBinary)
bytes = ((MySqlBinary)val).Value;
else
bytes = ((MySqlGuid)val).Bytes;
if (buffer == null)
return bytes.Length;
if (bufferoffset >= buffer.Length || bufferoffset < 0)
Throw(new IndexOutOfRangeException("Buffer index must be a valid index in buffer"));
if (buffer.Length < (bufferoffset + length))
Throw(new ArgumentException("Buffer is not large enough to hold the requested data"));
if (fieldOffset < 0 ||
((ulong)fieldOffset >= (ulong)bytes.Length && (ulong)bytes.Length > 0))
Throw(new IndexOutOfRangeException("Data index must be a valid index in the field"));
// adjust the length so we don't run off the end
if ((ulong)bytes.Length < (ulong)(fieldOffset + length))
{
length = (int)((ulong)bytes.Length - (ulong)fieldOffset);
}
Buffer.BlockCopy(bytes, (int)fieldOffset, buffer, (int)bufferoffset, (int)length);
return length;
}
public static byte[] convertBlobToBufferData(String column,MySqlDataReader rdr)
{
int bufferSize = 1024; // Number of bytes to read at a time
byte[] ImageData = new byte[bufferSize];
long nBytesReturned, startIndex = 0;
int ordinal = rdr.GetOrdinal(column);
string image = rdr.IsDBNull(ordinal) ? null : rdr.GetString(column);
if (image != null)
{
startIndex = 0;
nBytesReturned = rdr.GetBytes(
ordinal, // Column index of BLOB column
startIndex, // Start position of the byte to read
ImageData, // Byte array to recieve BLOB data
0, // Start index of the array
bufferSize // Size of buffer
);
while (nBytesReturned == bufferSize)
{
startIndex += bufferSize;
nBytesReturned = rdr.GetBytes(ordinal, startIndex, ImageData, 0, bufferSize); // Number of bytes returned is assigned to nBytesReturned
}
return ImageData;
}
else
{
return null;
}
}
