急可能是sendmessage的问题

[aliya]

unit Unit1;

interface

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

Const
SX_MyMessage = WM_USER + 101;
SX_MyMessage2 = WM_USER + 102;

TYPE
TECG = array[0..299] of integer;
const ecg1:TECG = ( 63, 63, 63, 63, 63, 64, 64, 65, 65, 66,//1
67, 68, 67, 67, 66, 65, 64, 63, 63, 63,
63, 63, 63, 63, 63, 63, 63, 63, 63, 63,
63, 60, 59, 61, 63, 73, 84, 95, 79, 63, //4
61, 60, 58, 57, 55, 57, 60, 60, 60, 60,
60, 60, 61, 61, 61, 62, 62, 62, 62, 62,
62, 63, 63, 63, 63, 64, 64, 65, 65, 65,
66, 66, 67, 68, 68, 69, 68, 67, 67, 67, //8
66, 65, 63, 62, 60, 60, 60, 60, 61, 61,
61, 61, 61, 62, 62, 62, 63, 63, 63, 63, //10
63, 63, 63, 63, 63, 63, 63, 63, 63, 63,
63, 63, 63, 63, 63, 63, 63, 63, 63, 63,
63, 63, 63, 63, 63, 63, 63, 63, 63, 63, //13
63, 63, 63, 63, 63, 63, 63, 63, 63, 63,
63, 63, 63, 63, 63, 63, 63, 63, 63, 63, //15
63, 63, 63, 63, 63, 64, 64, 65, 65, 66,//1
67, 68, 67, 67, 66, 65, 64, 63, 63, 63,
63, 63, 63, 63, 63, 63, 63, 63, 63, 63,
63, 60, 59, 61, 63, 73, 84, 95, 79, 63, //4
61, 60, 58, 57, 55, 57, 60, 60, 60, 60,
60, 60, 61, 61, 61, 62, 62, 62, 62, 62,
62, 63, 63, 63, 63, 64, 64, 65, 65, 65,
66, 66, 67, 68, 68, 69, 68, 67, 67, 67, //8
66, 65, 63, 62, 60, 60, 60, 60, 61, 61,
61, 61, 61, 62, 62, 62, 63, 63, 63, 63, //10
63, 63, 63, 63, 63, 63, 63, 63, 63, 63,
63, 63, 63, 63, 63, 63, 63, 63, 63, 63,
63, 63, 63, 63, 63, 63, 63, 63, 63, 63, //13
63, 63, 63, 63, 63, 63, 63, 63, 63, 63,
63, 63, 63, 63, 63, 63, 63, 63, 63, 63 //15
);

type
TForm1 = class(TForm)
PaintBox1: TPaintBox;
button1 : Tbutton;
Button2: TButton;

procedure Button1Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure Button2Click(Sender: TObject);
private
{ Private declarations }
public
Procedure SXMyMessage(var msg :TMessage);message SX_MyMessage;
Procedure SXMyMessage2(Var msg : TMessage); message SX_MyMessage2;
procedure drawdemo;
{ Public declarations }
procedure DrawWave(pt1:Tpaintbox;cc,ptwidth,newwidth :integer);
end;

var
Form1: TForm1;
arraytmp : integer;
demo : Boolean;

implementation

{$R *.dfm}

Procedure Tform1.SXMyMessage2(var Msg : TMessage);
Begin

End;

Procedure TForm1.SXMyMessage(var msg:TMessage);
Begin

if demo then
button1Click(Self)
Else
DrawWave(paintbox1,1,paintbox1.ClientWidth,arraytmp);
End;

procedure Tform1.drawWave(pt1:Tpaintbox;cc,ptwidth,newwidth:integer);
var
j,tmp: integer;
k : integer;
Begin
k := 1;
pt1.Canvas.Pen.Width := 1;
Case cc of
0 : pt1.Canvas.Pen.Color := ClRed;
1 : pt1.Canvas.Pen.Color := ClBtnFace;
End;
newwidth := newwidth * 4;
if newwidth >ptwidth then
tmp := newwidth mod ptwidth
Else
tmp := newwidth;
pt1.Canvas.MoveTo((tmp),ecg1[1]);
for j := tmp downto 1 do
Begin
pt1.Canvas.LineTo((j),ecg1[k]);
k := k+1;
k := k mod 300;
End;
End;

procedure TForm1.Button1Click(Sender: TObject);
begin
form1.drawdemo;
end;

Procedure TForm1.drawdemo;
Begin
if not demo then
arraytmp := PaintBox1.ClientWidth + 1;
if (arraytmp < form1.PaintBox1.ClientWidth) Then
Begin
DrawWave(paintbox1,1,paintbox1.ClientWidth,arraytmp-1);
DrawWave(paintbox1,0,paintbox1.ClientWidth,arraytmp);
Arraytmp := arraytmp + 1;
Sleep(20);
SendMessage(Handle,SX_MyMessage,0,0);
End;
End;

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

procedure TForm1.Button2Click(Sender: TObject);
begin
demo := false;
SendMessage(Handle,SX_MyMessage2,0,0);
end;

end.


是这样的,我想让程序在绘制过程中停止下来,但是点了button1后,它就要给完才结束,我点了button2呢,它有什么都不绘制,觉得很奇怪,可能不是sendmessage的问题,但是觉得用消息又应当能解决这个问题,所以就发到这里了.

[aliya]

我的button2发了个空消息过去是表示我的demo已经变成false了啊?
按照想法,点button1让它成绘图状态,button2就是让它停止不画了.

[aliya]

可以这么说,现在点了button1后,程序就在不停地绘图,button2是点都点不了,要等button1完全执行了,才能点到button2.

[alexanda2000]

在你的drawWave方法的循环里加上
Application.ProcessMessages;

[herman~~]

不大明白你的意思

Procedure Tform1.SXMyMessage2(var Msg : TMessage);
Begin

End;
button2里面发送了SendMessage(Handle,SX_MyMessage2,0,0);这个消息，当你SXMyMessage2过程，什么事情都没做，当然不绘制呀

[aliya]

我在drawWave的循环里加了application.ProcessMessage,停到是能停止,不过有时不点button2它还是要自己停止的.

[aliya]

我不知道这个application.Processmessage是不是有限定时间的.