"Master-Detail" Databinding von Listbox nach Textbox

[Elvis]

Hier mal'n Bleistift:

Delphi-Quellcode:

uses
  System.Collections.Generic,
  System.Windows.Forms;

type
  SampleClass2 = class
  public
    property SomeValue : String;
  end;

  SampleClass1 = class
  public
    property SomeValue : String;
    property Content   : SampleClass2 := new SampleClass2(SomeValue := 'noch nix drin'); readonly;
  end;

    
class method ConsoleApp.Main; 
begin
  var myForm := new Form();
  
  myForm.SuspendLayout();
  var lb := new ListBox();
  var tb := new TextBox();
  
  tb.Dock := DockStyle.Top;
  lb.Dock := DockStyle.Fill;
  
  var list := new List<SampleClass1>(3);
  list.Add(new SampleClass1(SomeValue := 'A'));
  list.Add(new SampleClass1(SomeValue := 'B'));
  list.Add(new SampleClass1(SomeValue := 'C'));
  
  lb.DataSource := list;
  lb.DisplayMember := 'SomeValue';
  
  tb.DataBindings.Add('Text', list, 'Content.SomeValue'); 
  
  myForm.Controls.AddRange([lb, tb]);
  
  myForm.ResumeLayout();
  
  Application.Run(myForm);
end;