Power Of Reflection, Generics, Extension Method When Combined

Reflection, Generics, and Extension methods are powerful features but with a little lateral thinking, these can be combined and we can find interesting solutions for problems.

Thus, I am here with an interesting piece of code, which combines all the features, mentioned above.

While doing coding, we often have to fill List<SelectListItem>. We have to take values from List<T>, extract the values from the selected properties and fill the List<SelectListItem>.

The objective of the piece of coding shown below is to write an extended generic method, which takes a List<T> as an input parameter and also has two more strings, which are property names of the classes and returns List<SelectListItem>

public static class ExtensionMethodClasses
{
public static List<SelectListItem> GetSelectListItem<T>(this List<T> lstValues, string PropertyText, string PropertyValue)
{
List<SelectListItem> lstSelectListItem = new List<SelectListItem>();
SelectListItem selLstItem;
foreach(T t in lstValues)
{
selLstItem = new SelectListItem()
{
Text = GetPropValue(t, PropertyText).ToString(),
Value = GetPropValue(t, PropertyValue).ToString()
};
lstSelectListItem.Add(selLstItem);
}
return lstSelectListItem;
}
public static object GetPropValue(object src, string propName)
{
return src.GetType().GetProperty(propName).GetValue(src, null);
}
}

Thus, the coding is self explanatory.

Now, let's look at an example, which uses this piece of coding.

The model is shown below.

public class ClassModel
{
public string ClassName { get; set; }
public List<StudentModel> students
{
get
{
return new List<StudentModel>()
{
new StudentModel()
{
StudentId = 1,
Name = "Name1",
Mark1 = 74.50M
},
new StudentModel()
{
StudentId = 2,
Name = "Name2",
Mark1 = 63.00M
},
new StudentModel()
{
StudentId = 3,
Name = "Name3",
Mark1 = 87.00M
},
new StudentModel()
{
StudentId = 4,
Name = "Name4",
Mark1 = 81.00M
}
};
}
}
}
public class StudentModel
{
public int StudentId { get; set; }
public string Name { get; set; }
public decimal Mark1 { get; set; }
}

The coding, shown below, uses the method which we created.

ClassModel cm = new ClassModel();
List<SelectListItem> selLstitem = cm.students.GetSelectListItem("Name", "StudentId");