delphi TClientDataSet[14]: 测试 FindFirst、FindNext、FindLast、FindPrior、Found

TClientDataSet[14]: 测试 FindFirst、FindNext、FindLast、FindPrior、Found

//先在窗体添加 ClientDataSet1 和两个 Button

{ 初始化测试数据 }

procedure TForm1.FormCreate(Sender: TObject);

begin

  with ClientDataSet1 do begin

    FieldDefs.Add('ID', ftInteger);

    FieldDefs.Add('Name', ftString, 6);

    FieldDefs.Add('Age', ftWord);

    CreateDataSet;

    AppendRecord([1, 'A',    11]);

    AppendRecord([2, 'AB',   22]);

    AppendRecord([3, 'ABC',  33]);

    AppendRecord([4, 'ABCD', 44]);

    AppendRecord([5, 'a',    55]);

    AppendRecord([6, 'ab',   66]);

    AppendRecord([7, 'abc',  77]);

    AppendRecord([8, 'abcd', 88]);

  end;

end;

{ FindFirst、FindNext、FindLast、FindPrior }

procedure TForm1.Button1Click(Sender: TObject);

begin

  ClientDataSet1.Filter := 'Name Like ''%c%''';

  ClientDataSet1.FilterOptions := [foCaseInsensitive];

  ClientDataSet1.Filtered := True;

  if ClientDataSet1.FindFirst then ShowMessage(ClientDataSet1['Name']); { ABC }

  if ClientDataSet1.FindNext then ShowMessage(ClientDataSet1['Name']);  { ABCD }

  if ClientDataSet1.FindLast then ShowMessage(ClientDataSet1['Name']);  { abcd }

  if ClientDataSet1.FindPrior then ShowMessage(ClientDataSet1['Name']); { abc }

  ClientDataSet1.Filtered := False;

end;

{ 遍历过滤结果 }

procedure TForm1.Button2Click(Sender: TObject);

begin

  ClientDataSet1.Filter := 'Name Like ''%c%''';

  ClientDataSet1.FilterOptions := [foCaseInsensitive];

  ClientDataSet1.Filtered := True;

  ClientDataSet1.FindFirst;

  while ClientDataSet1.Found do

  begin

    ShowMessage(ClientDataSet1['Name']); { ABC / ABCD / abc / abcd}

    ClientDataSet1.FindNext;

  end;

  ClientDataSet1.Filtered := False;

end;