SendTextMessage 等方便的消息发送函数

突然发现 Message 单元的最后给提供了几个方便的消息发送函数:
SendTextMessage、SendStructMessage、SendGetStructMessage、SendGetIntMessage

虽然函数实现的很简单, 但用他们发送文本、结构和整数, 的确方便了不少; 下面仅就 SendTextMessage 举例:

//例子是通过发送消息的方法给 Edit 赋值:
unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

//使用传统的 SendMessage
procedure TForm1.Button1Click(Sender: TObject);
var
  str: string;
begin
  str := '万一1';
  SendMessage(Edit1.Handle, WM_SETTEXT, 0, Integer(PChar(str)));
end;

//使用 VCL 的 Perform
procedure TForm1.Button2Click(Sender: TObject);
var
  str: string;
begin
  str := '万一2';
  Edit1.Perform(WM_SETTEXT, 0, Integer(PChar(str)));
end;

//使用 SendTextMessage 的确方便
procedure TForm1.Button3Click(Sender: TObject);
var
  str: string;
begin
  str := '万一3';
  SendTextMessage(Edit1.Handle, WM_SETTEXT, 0, str);
end;

//SendTextMessage 也可接受字符串常数
procedure TForm1.Button4Click(Sender: TObject);
begin
  SendTextMessage(Edit1.Handle, WM_SETTEXT, 0, '万一4');
end;

end.