Question

var leftCurrent = leftArray.GetValue(i);
var rightCurrent = rightArray.GetValue(i);

var mi = typeof (PropertyCompare).GetMethod("NotEqualProperties");
mi.MakeGenericMethod(leftCurrent.GetType());

var notEqualProps = mi.Invoke(null,new []{leftCurrent, rightCurrent});

if(notEqualProps != null) 
    result.Add(new ArraysDiffResult(i, notEqualProps as List<string>));

Why does this code throws InvalidOperationException ( Late bound operations cannot be performed on types or methods for which ContainsGenericParameters is true.) ?

NotEqualProperties is static generic method..

UPD : I’ve already found solution. Just forgot to assign new MethodInfo…(Epic Fail..)

But how about performance?

Answer 1

MakeGenericMethod returns a new MethodInfo instance. (MethodInfo is immutable)

Your code creates this new instance, throws it away, then continues using the open (non-parameterized) MethodInfo.

You need to use the new instance, like this:

mi = mi.MakeGenericMethod(leftCurrent.GetType());

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Yes; reflection is much slower than normal method calls.
However, unless you’re calling it in a tight loop, it’s not necessarily an issue.