how retreive the value of a property from object when propertyname in a variable ?

[fabianus]

how my I retreive the value of a property in an object when I stored the propertyname in a variable ?

I give you a little example of what I want to do. I wrote "Me.[en.Current]" for what I am looking for - how is the correct syntax ?

Public Class myClass

Dim myProperty As Integer

Public Function get_Datarow(ByVal field_list As ArrayList)
While en.MoveNext
Console.WriteLine( Me.[en.Current] )
End While
End Function
End Class

Thank you very much!
Fabian

[Memnoch1207]

Try something like this

Public Class myClass
 
   Private myProperty As Integer
 
   Public Function get_Datarow(ByVal field_list As ArrayList)
      While en.MoveNext
         Console.WriteLine( Me.[en.Current] )
      End While
   End Function
 
   Public Property myPropertyName() As Integer
      Get
         Return myProperty
      End Get
      Set (ByVal Value As Integer)
         myProperty = Value
      End Set
   End Property
End Class

[fabianus]

Hi Memnoch1207,

thank you for your answer.

I tried to understand... but I did not. Could you give me some more indication?

As you see I wrote "Me.[en.Current]" for the part that is missing to me.

I want to call a property from an object, but I have stored the propertyname in a variable.

This means I can not write

myClass.myPropertyName

because "myPropertyName" is stored in ma variable ! But I don't know the syntax...

of course if I wirte

myVariable = "myPropertyName"
Console.WriteLine(myClass.myVariable)

it doesn't work, because myVariable is not a proberty of myClass.

Thank you very much for some more help!

[nemaroller]

You will need Reflection to do this. You can find more information using MSDN and search for PropertyInfo.

//c#
	class SomeClass
	{
		public SomeClass(){}
		private int _level = 3;
		public int Level
		{
			get
			{
				return _level;
			}
			set
			{
				_level = value;
			}
		}

		/// <summary>
		/// The main entry point for the application.
		/// </summary>
		[STAThread]
		static void Main(string[] args)
		{
			//assign our propertyname to a string variable
			string propertyname = "Level";
			Type type;
			//instantiate an instance of SomeClass
			SomeClass someClass = new SomeClass();
			//Get the type of the SomeClass class.
			type = typeof(SomeClass);


			//Use the Reflection namespace PropertyInfo class to get the reflected info
			System.Reflection.PropertyInfo info = type.GetProperty(propertyname);
			//if the property has a get accessor
			if (info.CanWrite )
			{
				//call our instance 'someClass', setting its Level property to 10.
				info.SetValue(someClass,10,null);
			}

			//display to console to confirm it was assigned
			Console.WriteLine(someClass.Level.ToString());
			Console.ReadLine();
		
		}
	}

[nemaroller]

Here's a VB version

Public Class SomeClass
 
    Public Sub SomeClass()
 
    End Sub
 
    Private _level As Integer = 3
 
    Public Property Level()
        Get
            Return _level
        End Get
        Set(ByVal Value)
            _level = Value
        End Set
    End Property
 
    Public Shared Sub Main()
 
        Dim propertyname As String = "Level"
        Dim type As Type
 
        'instantiate an instance of SomeClass
        Dim someClass As SomeClass = New SomeClass
 
        'Get the type of the SomeClass class.
        type = GetType(SomeClass)
 
 
        'Use the Reflection namespace PropertyInfo class to get the reflected info
        Dim info As System.Reflection.PropertyInfo = type.GetProperty(propertyname)
 
        'if the property has a set accessor
        If (info.CanWrite) Then
 
            'call our instance 'someClass', setting its Level property to 10.
            info.SetValue(someClass, 10, Nothing)
 
        End If
 
        'display to console to confirm it was assigned
        Console.WriteLine(someClass.Level.ToString())
        Console.ReadLine()
 
    End Sub
End Class

[fabianus]

that's quite something :-)

absolutly great - thank you a lot, I could have search for this for an eternity