最大化最小化自定义窗口的尺寸

 

unit uBaseForm;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs;

type
  TPoint = record
    x: Integer;
    y: Integer;
  end;

  TMinMaxInfo = record
    ptReserved: TPoint;
    ptMaxSize: TPoint;
    ptMaxPosition: TPoint;
    ptMinTrackSize: TPoint;
    ptMaxTrackSize: TPoint;
  end;

  TWMGetMinMaxInfo = record
    Msg: Cardinal;
    Unused: Integer;
    MinMaxInfo: PMinMaxInfo;
    Result: Longint;
  end;

  TBaseForm = class(TForm)
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
  private
    procedure WMGetMinMaxInfo(var Message: TWMGetMinMaxInfo ); message WM_GETMINMAXINFO;
  end;

var
  BaseForm: TBaseForm;

implementation

{$R *.dfm}

procedure TBaseForm.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  Action := caFree;           
end;

procedure TBaseForm.WMGetMinMaxInfo(var Message: TWMGetMinMaxInfo);
begin
  with Message.MinMaxInfo^ do
  begin
    //ptMaxSize.X := Screen.Width; {Width when maximized}
    //ptMaxSize.Y := 200; {Height when maximized}
    ptMaxPosition.X := 0; {Left position when maximized}
    ptMaxPosition.Y := Application.MainForm.Height; {Top position when maximized}
    //ptMinTrackSize.X := 100; {Minimum width}
    //ptMinTrackSize.Y := 100; {Minimum height}
    ptMaxTrackSize.X := Screen.Width; {Maximum width}
    ptMaxTrackSize.Y := screen.Height - Application.MainForm.Height -25; {Maximum height}
  end;
  Message.Result := 0; {Tell windows you have changed minmaxinfo}
  inherited;
end;

end.