BinaryReader Object issues

Question

Hi all! I'm having issues with a basic C# program, on my first attempt. I'm getting a null object not instantiated error when I attempt to ReadByte in the second procedure:

public void Main(string FileName)
        {
            System.IO.FileStream FS = new System.IO.FileStream(FileName, System.IO.FileMode.Open);
            System.IO.BinaryReader BR = new System.IO.BinaryReader(FS);

            ReadHeader(ref BR);

            BR.Close();
            FS.Close();
        }

        private void ReadHeader(ref System.IO.BinaryReader BR)
        {
            for (int ii = 0; ii < 32; ii++)
            {
                MarkerInfo.Header.bB1_32[ii] = BR.ReadByte();
            }
       }

Any help, much appreciated!

Jan Montano · Answer

I haven't yet encountered that one but perhaps others have. Try putting it in a new topic. Every problem here is worth posting. Chances are more people will be able to read it if in a new topic. Cheers.

Steve · Answer

Thanks for your help I've got it working now and discovered how much initialising of objects I need to do. I have got another issue now but I don't think it is worthy of a new topic. I am now exporting the binary data to file using BinaryWriter and I'm just outputting the exact same data I have read in using BinaryReader. Stepping through the program everything appears to be in order but when I check the binary file extra zeros are appearing at seemingly random places. Has anyone seen this sort of thing with BinaryWriter before?

Jan Montano · Answer

hmm... strange. This works fine for me. public partial class Form1 : Form { MM_Format_Class MarkerInfo = new MM_Format_Class(); public Form1() { InitializeComponent(); } private void Form1_Load(object sender EventArgs e) { Process(); } private void Process() { System.IO.FileStream FS = new System.IO.FileStream(@c:	est.txt System.IO.FileMode.Open); System.IO.BinaryReader BR = new System.IO.BinaryReader(FS); ReadHeader(ref BR); BR.Close(); FS.Close(); } private void ReadHeader(ref System.IO.BinaryReader BR) { for (int ii = 0; ii { MarkerInfo.Header.bB1_32[ii] = BR.ReadByte(); } } } Could you try hardcoding the filename instead? and put 50 characters on the file.

Steve · Answer

Woops I didn't think of that! I'm not sure exactly what I'm doing wrong though. This is how I declare the byte array type: public class MM_Header_Class { public byte[] bB1_32 = new byte[32]; } and the parent class: public class MM_Format_Class { public MM_Header_Class Header = new MM_Header_Class(); } and in an initialise function the main variable: MM_Format_Class MarkerInfo = new MM_Format_Class(); but I still get the same issue. I know it must be something obvious can you see it?

Jan Montano · Answer

Perhaps MarkerInfo.Header.bB1_32 is not initialized. I assume it's initialized like this byte[] MarkerInfo.Header.bB1_32 = new byte[32]; I tried the code below and it works fine. private void Process() { System.IO.FileStream FS = new System.IO.FileStream(@c:	est.txt System.IO.FileMode.Open); System.IO.BinaryReader BR = new System.IO.BinaryReader(FS); ReadHeader(ref BR); BR.Close(); FS.Close(); } private void ReadHeader(ref System.IO.BinaryReader BR) { byte[] bytearray = new byte[32]; for (int ii = 0; ii { bytearray[ii] = BR.ReadByte(); } }