学习 Message(10): WM_CancelMode 消息测试

启动模式窗口, 当前窗口会收到一条 WM_CancelMode 消息; 改消息无参数.
本例效果图:


代码文件:

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Memo1: TMemo;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
  protected
    procedure WMCancelMode(var Message: TWMCancelMode); message WM_CANCELMODE;
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  Memo1.Align := alLeft;
  Memo1.ScrollBars := ssVertical;
  Memo1.Clear;
  Position := poScreenCenter;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  ShowMessage('ShowMessage');
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  InputBox('InputBox','Input','');
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  MessageBox(Handle, 'Test', 'MessageBox', 0);
end;

procedure TForm1.Button4Click(Sender: TObject);
var
  form: TForm;
begin
  form := TForm.Create(Self);
  form.Caption := 'Test';
  form.Width := Width div 2;
  form.Height := Height div 2;
  form.Position := poDesktopCenter;
  form.ShowModal;
end;

procedure TForm1.WMCancelMode(var Message: TWMCancelMode);
begin
  Memo1.Lines.Add('收到 WMCancelMode 消息');
  Message.Result := 0;
end;

end.

 
 
 
 
 

 

 
  

窗体文件:

object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 161
  ClientWidth = 301
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  OnCreate = FormCreate
  PixelsPerInch = 96
  TextHeight = 13
  object Memo1: TMemo
    Left = 8
    Top = 8
    Width = 185
    Height = 89
    Lines.Strings = (
      'Memo1')
    TabOrder = 0
  end
  object Button1: TButton
    Left = 207
    Top = 23
    Width = 75
    Height = 25
    Caption = 'Button1'
    TabOrder = 1
    OnClick = Button1Click
  end
  object Button2: TButton
    Left = 207
    Top = 54
    Width = 75
    Height = 25
    Caption = 'Button2'
    TabOrder = 2
    OnClick = Button2Click
  end
  object Button3: TButton
    Left = 207
    Top = 85
    Width = 75
    Height = 25
    Caption = 'Button3'
    TabOrder = 3
    OnClick = Button3Click
  end
  object Button4: TButton
    Left = 207
    Top = 116
    Width = 75
    Height = 25
    Caption = 'Button4'
    TabOrder = 4
    OnClick = Button4Click
  end
end