CODEWITHSUNDEEP
c#.netpropertiesexpression-trees
Vasile Tomoiaga
Vasile Tomoiaga

Reputation: 1747

Get the name of a property by passing it to a method

StackOverflow user jolson had a very nice piece of code that exemplifies how one can register menthods without using strings, but expression trees here.

Is it possible to have something similar for properties instead of methods? To pass a property (not the name of the property) and inside the method to obtain the property name?

Something like this:


    RegisterMethod(p => p.Name)

    void RegisterMethod(Expression??? propertyExpression) where T : Property ???
    {
        string propName = propertyExpression.Name;
    }

Thanks.

Upvotes: 4

Views: 786

Answers (2)

Marc Gravell
Marc Gravell

Reputation: 1062570

I posted a full example of this here (see also the post about "this" underneath it)

Note it deals with the LambdaExpression etc. As an update to the code as posted, you can add a bit more to make it easier to use in some scenarios:

static class MemberUtil<TType>
{
    public static string MemberName<TResult>(Expression<Func<TType, TResult>> member)
    {
        return MemberUtil.MemberName<TType, TResult>(member);
    }
}

Then you can use generic type-inference for the return value:

string test1 = MemberUtil<Foo>.MemberName(x => x.Bar); 
string test2 = MemberUtil<Foo>.MemberName(x => x.Bloop());

Upvotes: 7

Jb Evain
Jb Evain

Reputation: 17499

You can write something along this:

static void RegisterMethod<TSelf, TProp> (Expression<Func<TSelf, TProp>> expression)
{
    var member_expression = expression.Body as MemberExpression;
    if (member_expression == null)
        return;

    var member = member_expression.Member;
    if (member.MemberType != MemberTypes.Property)
        return;

    var property = member as PropertyInfo;
    var name = property.Name;

    // ...
}

Upvotes: 6

Related Questions