Using reflection with derived objects

Question

I am new to C# and need to perform a certain task using Reflection.

The thing is like this: I have a class called Derived which derives form a class called Base. Within the Base class I have another public class, which is a property called Prop class. Within the Prop class , there is a public property of type String called propString. Both Derived and Base class are under the same namespace. I depicted the situation below:

namespace mynamespace

public class Base {

    public Prop prop { get ; set;}


}

namespace mynamespace

public class Derived : Base {

    // some other properties of the derived class , not so relevant....
}


public class Prop {

     public String propString {get; set;}
}

I need to write two functions:

The first one receives a string of the "full path" of a property within a class and needs to extract the type of that property (In my case the string will be "Prop.propString" and the outcome of this method needs to be A PropertyInfo object with that property).

The second one gets an instance of an object and needs to perform a manipulation on the propString property (in my case the object that the function will get is A Derived object). I understood that it can be implemented in "more or less" that manner , yet it does not work well at the moment.

public void SecondFunc(Base obj) 
{
         PropertyInfo propertyInfo;
         object obj = new object();
         string value = (string)propertyInfo.GetValue(obj, null);

         string afterRemovalValue = myManipulationStringFunc(value);

         propertyInfo.SetValue(obj, afterRemovalValue, null);

}

Please your advises on how to implement these two functions, and off course any further insights you have will be highly appreciated.

Thanks allot in advance,

Guy.

Answer 1

I am not sure what you are trying to accomplish and if it is the best way to do it. But I have changed the code so it works. I have not made it as dynamic as it can be...

public class Base
{
    public Prop prop { get; set; }
}

public class Derived : Base
{

    // some other properties of the derived class , not so relevant....
}

public class Prop
{

    public String propString { get; set; }
}
public class MyClass
{
    public void SecondFunc(object obj)
    {
        Type type = obj.GetType();
        var allClassProperties = type.GetProperties();
        foreach (var propertyInfo in allClassProperties)
        {
            if (propertyInfo.PropertyType == typeof(Prop))
            {
                var pVal = (Prop)propertyInfo.GetValue(obj, null);
                if(pVal == null)
                {
                    //creating a new instance as the instance is not created in the ctor by default
                    pVal = new Prop();
                    propertyInfo.SetValue(obj, pVal, null);
                }
                this.SecondFunc(pVal);
            }
            else if (propertyInfo.PropertyType == typeof(string))
            {
                string value = (string)propertyInfo.GetValue(obj, null);
                string afterRemovalValue = myManipulationStringFunc(value);

                propertyInfo.SetValue(obj, afterRemovalValue, null);
            }
        }
    }

    private string myManipulationStringFunc(string value)
    {
        if (string.IsNullOrEmpty(value))
            value = "Value was NULL";
        return value;
    }
}

I hope this helps...