Difference Between Instr And Contains?

for determining whether a string of data contains certain text, which is more efficient? I have read elsewhere that there is somewhat of a consensus to avoid legacy functions, since they may or may not be available in future versions.However, trying to use the contains method (or indexof equivalent of Instr) is causing me problems, I think, because I am having trouble performing a case-insensitive search.

I am trying to be efficient and functional in my code. I am reading an INI file, and I have preloaded the contents of the file into a String variable, for 2 reasons. 1) If I can test if a certain section exists in the code, I can avoid attempting to read a section of empty data (the INI reader class I have chosen returns the value or an empty string for a given request). More importantly, 2) I have created a data field that is not INI compliant (at least not to the API?) as it is a data field that can contain an arbitrary (unlimited?) amount of data which is a hex-encoded representation of serialized byte data. I need to be able to determine if this value exists in the file and retrieve it using normal string manipulation, since the INI handler will not pass strings longer than 256Chr.

So, the problem I am having is getting "strFileContents.Contains("data=")" to return true in the case where the file contains "Data=". This could be data=, DATA=, DaTa=, etc.Instr has the option "CompareMethod.Text" which, I believe, does a case insensitive text search. What is the equivalent for "Contains"?