I have the following string expression defining the object traversal "e.B.num". where e defines the root entity in my string expression
class BTest
{
public int num{get:set;}
}
class Test
{
public int sample {get; set;}
public BTest B {get; set;}
}
static void TestProperty()
{
Test obj = new Test();
obj.sample = 40;
obj.B = new BTest(){ num=5}
Expression propertyExpr = Expression.Property(Expression.Constant(obj),"num");
Console.WriteLine(Expression.Lambda<Func<int>>(propertyExpr).Compile()());
}
On the below statement Expression.Property(Expression.Constant(obj),"num"); I am able to get the value for the first level property "sample" but not for the second level property?
Am I missing something here? I am trying to build a binary expression post this based on the "num" property value.
You have to create nested property expression as you're looking for nested property.
Expression bExpression = Expression.Property(Expression.Constant(obj), "B");
Expression numExpression = Expression.Property(bExpression, "num");
Console.WriteLine(Expression.Lambda<Func<int>>(numExpression).Compile()());//Prints 5