Kyle Kyle - 3 months ago 13
C# Question

How can I emulate "typeof (T)" using the System.Linq.Expressions API?

I'm trying to create a method that will create a

DataTable
from a list of objects using the
System.Linq.Expressions
API, but I can't figure out how to generate the following IL that I get when I decompile the expression
typeof (int)
.

IL_0000: nop
IL_0001: ldtoken System.Int32
IL_0006: call System.Type.GetTypeFromHandle
IL_000B: call LINQPad.Extensions.Dump<Object>
IL_0010: pop
IL_0011: ret


Currently I'm trying to skirt the problem by calling
Type.GetType("System.Int")
instead, but I would like to generate the code for
typeof (int)
if at all possible.

Answer

Just use Expression.Constant and pass in typeof(int) as the value:

var expression = Expression.Constant(typeof(int), typeof(Type));

That's what happens when you use typeof within a lambda expression, anyway:

Expression<Func<Type>> func = () => typeof(T);