public class Job
{
public string Name { get; set; }
public int Salary { get; set; }
}
public class Employee
{
public string Name { get; set; }
public Job Job { get; set; }
}
If I want to create an expression tree of a member access to Employee.Name this is what I do:
var param = Expression.Parameter(type, "x");
var memberAccess = Expression.PropertyOrField(param, memberName);
return Expression.Lambda<Func<TModel, TMember>>(memberAccess, param);
What is the equivalent to this for a member access to Employee.Job.Salary ?
You need:
var jobProperty = Expression.PropertyOrField(param, "Job");
var salaryProperty = Expression.PropertyOrField(jobProperty, "Salary");
Basically you're taking the Salary
property from the result of evaluating x.Job
.
If you need to do this in a programmatic way, you'll need something like:
Expression expression = Expression.Parameter(type, "x");
foreach (var property in properties.Split('.'))
{
expression = Expression.PropertyOrField(expression, property);
}