Dot Net Thoughts

In series of Reflection related posting this is the second post. You can see the post here. Now I am posting about Properties. We can set / read properties of Class using reflection.

Setting Properties

1) For setting properties, we enumerate all the properties using Type.GetProperties() method
2) Then we will check, whether the property is readonly or not.
3) Read the value(if the datatype of property and the datatype of the value you are trying to set, didn’t match it will throw some error.)
4) If datatype is mismatching, convert the value to property data type using “Convert.ChangeType” *
5) Call the PropertyInfo.SetValue method.

Here is the source code, here I am reading from Registry and Loads the required data in a class level variable.

Dim result As MyCustomClass
Dim PropertyValue As Object
Dim converter As New TypeConverter
For Each CurrentProperty As PropertyInfo In MyType.GetProperties
If CurrentProperty.CanWrite Then
PropertyValue = GetValue(CurrentProperty.Name)	'GetValue function retuns the value based on the parameter given.
If PropertyValue IsNot Nothing Then
	CurrentProperty.SetValue(result, Convert.ChangeType(PropertyValue, CurrentProperty.PropertyType), Nothing)
End If
End If
Next

* Convert.ChangeType – Works only with basic datatypes.

And for getting we will do almost reverse operation.
Getting values from Property

It is simple and strait forward, and here is the code

Dim propertyValue As String
For Each CurrentProperty As PropertyInfo In MyType.GetProperties
If CurrentProperty.CanRead Then
propertyValue = CurrentProperty.GetValue(MyCustomClass, Nothing).ToString
End If
Next

Happy Reflection.