Is there a way to get the value of a variable just by knowing the name of it, like this:
double temp = (double)MyClass.GetValue("VariableName");
When I normally would access the variable like this
double temp = MyClass.VariableName;
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1I'm curious as to what context you would need to do this, where accessing a value as a property normally would not suffice.Corey Sunwold– Corey Sunwold2011-02-19 21:10:45 +00:00Commented Feb 19, 2011 at 21:10
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1 Answer
You could use reflection. For example if PropertyName is a public property on MyClass and you have an instance of this class you could:
MyClass myClassInstance = ...
double temp = (double)typeof(MyClass).GetProperty("PropertyName").GetValue(myClassInstance, null);
If it's a public field:
MyClass myClassInstance = ...
double temp = (double)typeof(MyClass).GetField("FieldName").GetValue(myClassInstance);
Of course you should be aware that reflection doesn't come free of cost. There could be a performance penalty compared to direct property/field access.
6 Comments
Emond
Be careful; it might be very slow using this frequently.
Andreas
Would reflection be slower then a 10 case switch filter?
Darin Dimitrov
@Andeas, no freaking idea, I bet 5 bucks reflection would be slower but the best would be to measure it in order to be sure and you'd better be sure before putting some code in production.
R. Martinho Fernandes
@Andreas: I bet. A 10 case switch filter is about as slow as a 3 case switch filter.
Daniel Pryden
@Andreas: Just chiming in with what others are saying here. I had a project where I replaced a reflection-based solution with a switch/case and got more than an order of magnitude speedup in several tight loops. For more complex scenarios, it's also worth trying a delegate wrapping a lambda that just fetches the property -- those also can beat reflection by an order of magnitude or more.
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