Reading field of 'Long' datatype from binary file in C#?

Question

Hi, Need to read a field of 'Long' datatype from a binary file in my C# program. I am able to read fields of 'character' type. But, do not know how to read the 'Long' field. If i read 4 bytes, cast them one by one to chars and then concatenate, i am getting junk value. Need your help pls. Thanks in advance. Regards, Peri