您可以使用TControlList.ItemIndex取得选取的项目。
一种解决方案是创建一个方法，删除fdmedcin中的条目，然后像示例中那样重新设置TControlList.ItemCount。

form1.ControlList1.ItemCount := fdmedcin.RecordCount;

我不知道你的确切代码，但它可能看起来像这样：

procedure TForm1.Delete;
begin
  dm.fdmedcin.RecNo := ControlList1.ItemIndex + 1; // seems like you add one in your OnBeforeDrawItem too
  dm.fdmedcin.Delete;
  ControlList1.ItemCount := fdmedcin.RecordCount;
end;

换句话说就是：必须将TControlList.ItemIndex与DataSet/whatever索引匹配。
我用TList<T>做了一个简单的例子，而T是integer：

type
  TForm2 = class(TForm)
    BFill: TButton;
    ControlList1: TControlList;
    Label1: TLabel;
    Panel1: TPanel;
    BDelete: TButton;
    MSQuery1: TMSQuery;
    procedure BFillClick(Sender: TObject);
    procedure ControlList1BeforeDrawItem(AIndex: Integer; ACanvas: TCanvas; ARect: TRect; AState: TOwnerDrawState);
    procedure FormCreate(Sender: TObject);
    procedure BDeleteClick(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    { Private declarations }
    FList: TList<integer>;
  public
    { Public declarations }
  end;

var
  Form2: TForm2;

implementation

{$R *.dfm}

procedure TForm2.BDeleteClick(Sender: TObject);
begin
  FList.Delete(ControlList1.ItemIndex);
  ControlList1.ItemCount := FList.Count;
end;

procedure TForm2.BFillClick(Sender: TObject);
begin
  ControlList1.ItemCount := FList.Count;
end;

procedure TForm2.ControlList1BeforeDrawItem(AIndex: Integer; ACanvas: TCanvas; ARect: TRect; AState: TOwnerDrawState);
begin
  Label1.Caption := IntToStr(FList[AIndex]);
end;

procedure TForm2.FormCreate(Sender: TObject);
var
  i: integer;
begin
  FList := TList<integer>.Create;
  for i := 0 to 9 do
    FList.Add(i);
end;

procedure TForm2.FormDestroy(Sender: TObject);
begin
  FList.Free;
end;