How costly is .NET reflection?

c# .net performance reflection
Dan Herbert picture Dan Herbert · Aug 25, 2008 · Viewed 60.8k times · Source

I constantly hear how bad reflection is to use. While I generally avoid reflection and rarely find situations where it is impossible to solve my problem without it, I was wondering...

For those who have used reflection in applications, have you measured performance hits and, is it really so bad?

Answer

ESRogs picture ESRogs · Aug 27, 2008

In his talk The Performance of Everyday Things, Jeff Richter shows that calling a method by reflection is about 1000 times slower than calling it normally.

Jeff's tip: if you need to call the method multiple times, use reflection once to find it, then assign it to a delegate, and then call the delegate.

Related questions

How to create a new object instance from a Type

One may not always know the Type of an object at compile-time, but may need to create an instance of the Type. How do you get a new object instance from a Type?

Read More
Best way to reverse a string

I've just had to write a string reverse function in C# 2.0 (i.e. LINQ not available) and came up with this: public string Reverse(string text) { char[] cArray = text.ToCharArray(); string reverse = String.Empty; for (int i = cArray.Length - 1; …

Read More
What's the fastest way to read a text file line-by-line?

I want to read a text file line by line. I wanted to know if I'm doing it as efficiently as possible within the .NET C# scope of things. This is what I'm trying so far: var filestream = new System.…

Read More