Reflecting Properties

[Diesel]

I have a class in which I create two objects, one I fill with data and the other is a copy of the first. Im using reflection to get the public properties of each class...

 

 Dim myType As Type = GetType(ECSolutions.Inventory.Vehicle)
           ' Get the public properties.
           Dim myPropertyInfo As System.Reflection.PropertyInfo() = Me.GetType.GetProperties((BindingFlags.Public Or BindingFlags.Instance))
           Dim hisPropertyInfo As PropertyInfo() = obj.GetType.GetProperties((BindingFlags.Public Or BindingFlags.Instance))

 

But now, im trying to compare the actual values in the properties with no luck...any help?

 

For Each prop In myPropertyInfo
               If CType(prop.GetValue(prop, i), String) <> CType(hisPropertyInfo(i).GetValue, String) Then Return 0
               i += 1
               End If
           Next

[Joe Mamma]

back up. . .

 

Look at implementing IComparable, or overriding the Equals method on your contained class.

 

Drop the old VB way of doing things!!!!

 

CType is not .NET

 

Iterating through the properties is procedural.

At runtime a class instance should know who to compare itself to other objects. ala:

 

If class1.CompareTo(class2) <> 0 then

DoSomething

end if

 

or

 

If not class1.Equals(class2) then

DoSomething

end if

 

though overriding Equals is probably not advised except in the most basic of situations due to side effects.

[Diesel]

Really?

 

I am using IComparable...the above code was the implementation inside CompareTo.

Im not comparing a class though, Im comparing objects. I want to make sure the data in the objects is exactly the same. I think I found something in propertydescriptioncollection.

What are the side effects of overriding Equals?

[PlausiblyDamp]

If you are implementing IComparable then you may as well just compare the fields yourself - using reflection will cause a performance hit for something as simple as this.

[Diesel]

Oh IC

 

Ok, then, I'll just do it manually. I guess I was just trying to make it flexible, but your right, it's probably not worth it.

[Diesel]

Wait a sec...

 

Ctype is not .Net? It is a checked function, check the declaration...How else can you typecast in VB.net?

[PlausiblyDamp]

Depends what you are converting between, to convert to a string all objects will implement a .ToString() method. Other data type often have their own method i.e. Integer.Parse() to convert a string to an integer.

[Diesel]

What about...

 

What about converting one object to another...say a parent class to a subclass

 

Say you have a function that takes a superclass as a parameter, but you want to use a property of the subclass....

 

Public Function PrintAttributes(obj as Person) as String

 

Dim str as string

 

str = obj.name

str &= obj.age

str &= Ctype(obj, Employee).jobtitle

 

End Function

[PlausiblyDamp]

In that case use DirectCast instead of CType