static extern bool WinHttpReadData(IntPtr hRequest,byte[] lpBuffer,int dwNumberOfBytesToRead,ref int lpdwNumberOfBytesRead);

Declare Function WinHttpReadData Lib "winhttp.dll" (ByVal hRequest As IntPtr, ByVal lpBuffer As Byte(), ByVal dwNumberOfBytesToRead As Integer, ByRef lpdwNumberOfBytesRead As Integer) As Boolean