drawform.pas

这是一本关于delphi方面的书籍,其中有一些delphi的实例.

unit DrawForm;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  DBTables, DB, Grids, DBGrids, ExtCtrls, StdCtrls, DBCtrls;

type
  TForm1 = class(TForm)
    DataSource1: TDataSource;
    DBGrid1: TDBGrid;
    Table1: TTable;
    Table1SpeciesNo: TFloatField;
    Table1Category: TStringField;
    Table1Common_Name: TStringField;
    Table1Lengthcm: TFloatField;
    Table1Notes: TMemoField;
    Table1Graphic: TGraphicField;
    procedure DBGrid1DrawColumnCell(Sender: TObject; const Rect: TRect;
      DataCol: Integer; Column: TColumn; State: TGridDrawState);
    procedure FormCreate(Sender: TObject);
    procedure Table1NotesGetText(Sender: TField; var Text: String;
      DisplayText: Boolean);
    procedure Table1NotesSetText(Sender: TField; const Text: String);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.DBGrid1DrawColumnCell(Sender: TObject; const Rect: TRect;
  DataCol: Integer; Column: TColumn; State: TGridDrawState);
var
  Bmp: TBitmap;
  OutRect: TRect;
  BmpWidth: Integer;
begin
  // default output rectangle
  OutRect := Rect;

  if Column.Field = Table1Common_Name then
  begin
    // draw the image
    Bmp := TBitmap.Create;
    try
      Bmp.Assign (Table1Graphic);
      BmpWidth := (Rect.Bottom - Rect.Top) * 2;
      OutRect.Right := Rect.Left + BmpWidth;
      DBGrid1.Canvas.StretchDraw (OutRect, Bmp);
    finally
      Bmp.Free;
    end;
    // reset output rectangle, leaving space for the graphic
    OutRect := Rect;
    OutRect.Left := OutRect.Left + BmpWidth;
  end;

  // red font color if length > 100
  if (Column.Field = Table1Lengthcm) and
      (Table1Lengthcm.AsInteger > 100) then
    DBGrid1.Canvas.Font.Color := clRed;

  // default drawing
  DBGrid1.DefaultDrawDataCell (OutRect, Column.Field, State);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Table1.Active := True;
end;

procedure TForm1.Table1NotesGetText(Sender: TField; var Text: String;
  DisplayText: Boolean);
begin
  Text := Trim (Sender.AsString);
end;

procedure TForm1.Table1NotesSetText(Sender: TField; const Text: String);
begin
  Sender.AsString := Text;
end;

end.