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Delphi中多線程用消息實現(xiàn)VCL數(shù)據(jù)同步顯示Lanno Ckeeke 2006-5-12概述：delphi中嚴格區(qū)分主線程和子主線程，主線程負責GUI的更新，子線程負責數(shù)據(jù)運算，當數(shù)據(jù)運行完畢后，子線程可以向主線程式發(fā)送消息，以便通知其將VCL中的數(shù)據(jù)更新。實現(xiàn)：關(guān)鍵在于消息的發(fā)送及接收。在消息結(jié)構(gòu)Tmessage中wParam和lParam類型為Longint，而指針類型也定義為Longint，可以通過此指針來傳遞自己所感興趣的數(shù)據(jù)。如傳遞字符數(shù)組：數(shù)組定義：              const MAX_LEN = 260;              szName : array[0..MAX_LEN] of Char; 消息發(fā)送方式：              PostMessage(Form1.Handle,WM_UPDATEDATA,Integer(PChar(@szName)),0);消息接收方式：              procedure TForm1.WMUpdateData(var msg : TMessage);begin       self.ShowData.Items.Add(PChar(msg.WParam));end;  子線程中定義兩個數(shù)據(jù)類型： public     szName : array[0..MAX_LEN] of Char;    nIndex : Integer;  完整代碼：子線程類：unit TChildThread; interface uses Classes,Messages,Windows,SysUtils;//添加的使用文件 const MAX_LEN = 260;type TChildThreads = class(TThread) private    { Private declarations } protected    procedure Execute; override; public      szName : array[0..MAX_LEN] of Char;    nIndex : Integer; end; implementationuses       Unit1; { Important: Methods and properties of objects in VCL or CLX can only be used in a method called using Synchronize, for example,       Synchronize(UpdateCaption);  and UpdateCaption could look like,     procedure TChildThread.UpdateCaption;    begin      Form1.Caption := 'Updated in a thread';    end; } { TChildThread } procedure TChildThreads.Execute;begin { Place thread code here }   PostMessage(Form1.Handle,WM_UPDATEDATA,Integer(PChar(@szName)),0);   //注意類型轉(zhuǎn)化部分的寫法end; end. 主線程代碼：unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, ComCtrls; const       WM_UPDATEDATA = WM_USER + 100;//自定義的消息，利用此消息來實現(xiàn)對GUI的更新type TForm1 = class(TForm)    ControlPannel: TGroupBox;    StartThreads: TButton;    TabControl1: TTabControl;    SingleThread: TRadioButton;    MultipleThreads: TRadioButton;    StopThreads: TButton;    ShowData: TListBox;    ShowError: TListBox;    Initialize: TButton;Cleanup: TButton;//GUI更新的消息處理函數(shù)聲明     procedure WMUpdateData(var msg : TMessage);message WM_UPDATEDATA;    procedure StartThreadsClick(Sender: TObject); private    { Private declarations } public    { Public declarations } end; var Form1: TForm1; implementationuses       TChildThread; {$R *.dfm}//消息函數(shù)定義procedure TForm1.WMUpdateData(var msg : TMessage);begin       self.ShowData.Items.Add(PChar(msg.WParam));end; procedure TForm1.StartThreadsClick(Sender: TObject);var       oChildThread : array[0..1000] of TChildThreads; i : Integer;begin       For i := 0 to 1000 do begin     oChildThread[i] := TChildThreads.Create(true);    //向VCL中發(fā)送的數(shù)據(jù)    strcopy(@oChildThread[i].szName,PChar('Child' + IntToStr(i)));    oChildThread[i].nIndex := i;    oChildThread[i].Resume; end; end; end.