利用RegisterWindowMessage在不同程序窗体间传递消息

最新推荐文章于 2022-10-06 16:09:20 发布

转载最新推荐文章于 2022-10-06 16:09:20 发布 · 3k 阅读

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本文介绍了一个使用Delphi实现的简单示例，通过注册自定义窗口消息并在两个窗体间进行消息传递来实现跨窗体截图的功能。具体包括如何在发送方窗体注册并发送自定义消息，以及接收方窗体如何捕获该消息并完成截图。

unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; type TForm1 = class(TForm) Button1: TButton; Button2: TButton; procedure FormCreate(Sender: TObject); procedure Button1Click(Sender: TObject); procedure Button2Click(Sender: TObject); private { Private declarations } UserMessage : UINT; public { Public declarations } end; var Form1: TForm1; implementation {$R *.dfm} procedure TForm1.Button1Click(Sender: TObject); begin sendmessage(HWND_BROADCAST,UserMessage ,handle,0); end; procedure TForm1.FormCreate(Sender: TObject); begin UserMessage := RegisterWindowMessage('WM_SAMPLE'); end; end.

unit Unit2; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, ExtCtrls; type TForm2 = class(TForm) Image1: TImage; procedure FormCreate(Sender: TObject); private { Private declarations } UserMessage : UINT; procedure GetImage(Form1Window : HWND); public { Public declarations } protected procedure WndProc(var Message: TMessage); override; end; var Form2: TForm2; implementation {$R *.dfm} procedure TForm2.FormCreate(Sender: TObject); begin UserMessage := RegisterWindowMessage('WM_SAMPLE'); end; procedure TForm2.WndProc(var Message: TMessage); begin if Message.Msg = UserMessage then GetImage(Message.WParam) else inherited; end; procedure TForm2.GetImage(Form1Window : HWND); var Form1DC: HDc; Form1Rect: TRect; begin image1.Picture := nil; Form1DC := GetWindowDC(Form1Window); GetWindowRect(Form1Window,Form1Rect); image1.Width := Form1Rect.Right-Form1Rect.Left; image1.Height := Form1Rect.Bottom - Form1Rect.Top; BitBlt(Image1.Canvas.Handle,0,0,image1.Width, image1.Height, Form1DC, 0, 0, SRCCOPY); Image1.Refresh; ReleaseDC(Form1Window, Form1DC); SetForegroundWindow(handle); beep; end; end.