Casting DataTable to Control

Question

I'd like to write a general method to dispose of SQL objects using a passed Form object. I'm running Visual Studio Express 2013 for Windows Desktop. The cast is the problem; see the lines with '**'. What type of cast should I use? Thanks!
public static void Dispose_SQLObjects(Form form)
foreach(Control control in form.Controls)
if (control.GetType() == typeof(DataTable))
**DataTable table = (DataAdapter)control;
if (table != null) table.Dispose();
if (control.GetType() == typeof(DataAdapter))
**DataAdapter adapter = (DataAdapter)control;
if (adapter != null) adapter.Dispose();
if (control.GetType() == typeof(BindingSource))
**BindingSource bs = (BindingSource)control;
if (bs != null) bs.Dispose();

Answer 1

I don't know what you are trying to do here.You can't make any cast on anything here in what you are trying to do.
https://msdn.microsoft.com/en-us/library/system.data.common.dataadapter%28v=vs.110%29.aspx?f=255&MSPPError=-2147217396
https://msdn.microsoft.com/en-us/library/system.data.datatable%28v=vs.110%29.aspx?f=255&MSPPError=-2147217396
https://msdn.microsoft.com/en-us/library/system.windows.forms.control(v=vs.110).aspx
Java and .NET have the same principles when it come to OO.
https://alfredjava.wordpress.com/2008/07/08/class-vs-object-vs-instance/
A class defines an object
A class can be instanciated into a object instance.
**DataTabletable
= (DataAdapter)control;
That statement is saying car I am telling you that you are going to be a house. And once you are a house, I am going to make you a rocket. It's never going to happen. .NET is going to start looking at the defining classe for the objects and say car you can't
be cast to be a house,  and house you can't be cast to be a rocket.
It's car cast to a car. It's house cast to a house. It's rocket cast to a rocket.
Lets say Textbox1 is cast to Object. That can happen becuase System.Object is the base object for everything in .NET. So you pass Object around in code. Object is really a Textbox object. So you get to a point in code where Object needs to be a Textbox object
again.
Textbox thetextbox = (TextBox)Object.  That's valid and I hope you understand way it is valid.