I have a FileType class which I am using to get the file type of a file. The goal consists of loading the file into a string and analyzing the bytes of the string to detect if a known file type is recognized.

In that FileType() method, I am loading the file into memory such as this:

				Using loStreamReader As New StreamReader(lcFile, System.Text.Encoding.Default)
					cString = loStreamReader.ReadToEnd()
				End Using

In our daily operations, we process about 4000 zip files, where each of them contains about 30 or more files, where I have to get the file type of each. So, basically, this method is called about 120000 times on a daily basis. I see this is, of course, impacted by the size of the file. So, if the file is bigger, it will take more time to do the above.

Would there be any faster way to achieve this?