使用LINQ中的PropertyInfo对象查询集合

Question

I have a method with a signature like this

void RefreshMethod<T>(IEnumerable<T> lst, string propertyName) where T:class
{
   Type type = typeof(T);
   PropertyInfo property = type.GetProperties().Single(u => u.Name == primaryKeyProperty);
  //query goes here
}

Now i want to query that collection for getting all the values whose

propertyName < 0

In a simple scenario it would be as easy as this

lst.where(u=>u.ID<0)

But here i don't have that ID property but have corresponding "PropertyInfo" object.

How should i acheive this.

kindly guide

Answer 1

You can lookup the property-value using property.GetValue(anObjectOfTypeT, null) .

So something like:

var refreshedList =  lst.Where(l => ((int)(property.GetValue(l, null)) < 0).ToList();

This assumes the property will always be of type int though.