Question

我有以下示例代码集，如何使用LiveBindings将Data列表元素绑定到TStringGrid。我需要双向更新，以便在网格中的列更改时，它可以更新基础TPerson。

我已经看到了如何使用基于TDataset的绑定执行此操作的示例，但我需要在没有TDataset的情况下执行此操作。

unit Unit15;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.Grids, System.Generics.Collections;

type
  TPerson = class(TObject)
  private
    FLastName: String;
    FFirstName: string;
  published
    property firstname : string read FFirstName write FFirstName;
    property Lastname : String read FLastName write FLastName;
  end;

  TForm15 = class(TForm)
    StringGrid1: TStringGrid;
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    Data : TList<TPerson>;
  end;


var
  Form15: TForm15;



implementation

{$R *.dfm}

procedure TForm15.FormCreate(Sender: TObject);
var
 P : TPerson;
begin
  Data := TList<TPerson>.Create;
  P := TPerson.Create;
  P.firstname := 'John';
  P.Lastname := 'Doe';
  Data.Add(P);
  P := TPerson.Create;
  P.firstname := 'Jane';
  P.Lastname := 'Doe';
  Data.Add(P);
  // What can I add here or in the designer to link this to the TStringGrid.
end;

end.

Answer 1

部分解决方案：从TList到TStringGrid是：

procedure TForm15.FormCreate(Sender: TObject); 
var 
 P : TPerson; 
 bgl: TBindGridList;
 bs: TBindScope;
 colexpr: TColumnFormatExpressionItem;
 cellexpr: TExpressionItem;
begin 
  Data := TList<TPerson>.Create; 
  P := TPerson.Create; 
  P.firstname := 'John'; 
  P.Lastname := 'Doe'; 
  Data.Add(P); 
  P := TPerson.Create; 
  P.firstname := 'Jane'; 
  P.Lastname := 'Doe'; 
  Data.Add(P); 
  // What can I add here or in the designer to link this to the TStringGrid. 

  while StringGrid1.ColumnCount<2 do
    StringGrid1.AddObject(TStringColumn.Create(self));

  bs := TBindScope.Create(self);

  bgl := TBindGridList.Create(self);
  bgl.ControlComponent := StringGrid1;
  bgl.SourceComponent := bs;

  colexpr := bgl.ColumnExpressions.AddExpression;
  cellexpr := colexpr.FormatCellExpressions.AddExpression;
  cellexpr.ControlExpression := 'cells[0]';
  cellexpr.SourceExpression := 'current.firstname';

  colexpr := bgl.ColumnExpressions.AddExpression;
  cellexpr := colexpr.FormatCellExpressions.AddExpression;
  cellexpr.ControlExpression := 'cells[1]';
  cellexpr.SourceExpression := 'current.lastname';

  bs.DataObject := Data;
end;

LiveBindings - TList <tmyobject>绑定到TStringGrid </tmyobject>

1 个答案: