VB.NET 'With' statement performance?

What's the performance consequence using the 'With' keyword i开发者_运维技巧n vb.net instead of using reusing the instance name over and over?

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Assuming that you're comparing it to a local variable reference, there is no difference whatsoever; both will emit the exact same IL. (At least in Release mode)

However, if you're comparing it to repeated invocations of a property or indexer, With will be a little bit faster, and if you're comparing it to repeated invocations of a method, it might be much faster. (The With keyword will create a local variable and assign it to the object that you With'd, so the method will only be called once instead of on every line)

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There is no runtime performance cost. It is just "syntactic sugar" to make your code look prettier.

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sub xyz (ByRef param as MyObj)

'Local ref, same as with

dim o2 as YourObject = param.YourObject

o2.callSomething()


'Bad performance

param.YourObject.callSomething()

end sub