MdDsList.pas
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上传用户:fh681027
上传日期:2022-07-23
资源大小:1959k
文件大小:1k
源码类别:
Delphi控件源码
开发平台:
Delphi
- unit MdDsList;
- interface
- uses
- DB, Classes, SysUtils, Windows, Forms, Contnrs, MdDsCustom;
- type
- TMdListDataSet = class (TMdCustomDataSet)
- protected
- // the list holding the data
- FList: TObjectList;
- // dataset virtual methods
- procedure InternalPreOpen; override;
- procedure InternalClose; override;
- // custom dataset virtual methods
- function InternalRecordCount: Integer; override;
- procedure InternalLoadCurrentRecord (Buffer: PChar); override;
- end;
- implementation
- procedure TMdListDataSet.InternalPreOpen;
- begin
- FList := TObjectList.Create (True); // owns objects
- FRecordSize := 4; // an integer, the list item id
- end;
- procedure TMdListDataSet.InternalClose;
- begin
- FList.Free;
- inherited;
- end;
- procedure TMdListDataSet.InternalLoadCurrentRecord (Buffer: PChar);
- begin
- PInteger (Buffer)^ := fCurrentRecord;
- with PMdRecInfo(Buffer + FRecordSize)^ do
- begin
- BookmarkFlag := bfCurrent;
- Bookmark := fCurrentRecord;
- end;
- end;
- function TMdListDataSet.InternalRecordCount: Integer;
- begin
- Result := fList.Count;
- end;
- end.