验证Event的全局性

思路很简单, 创建一事件,再创建一线程等待事件,再用OpenEvent根据事件名称打开,

MSDN说明:

Fast user switching is implemented using Terminal Services sessions. The first user to log on uses session 0, the next user to log on uses session 1, and so on. Kernel object names must follow the guidelines outlined for Terminal Services so that applications can support multiple users.

看得出事件具有传递性

代码
unit Unit1;

interface

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

type
  TestThread 
= class(TThread)
  
private
    I: Integer;
    
procedure ShowMsg;
  
protected
    
procedure Execute; override;
  
public
  
end;

  TForm1 
= class(TForm)
    Button1: TButton;
    Memo1: TMemo;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    Button5: TButton;
    Button6: TButton;
    Button7: TButton;
    
procedure Button1Click(Sender: TObject);
    
procedure Button2Click(Sender: TObject);
    
procedure Button3Click(Sender: TObject);
    
procedure Button4Click(Sender: TObject);
    
procedure Button5Click(Sender: TObject);
    
procedure Button6Click(Sender: TObject);
    
procedure Button7Click(Sender: TObject);
  
private
    
{ Private declarations }
  
public
    
{ Public declarations }
  
end;

var
  Form1: TForm1;
  GHandle, GHandle1: THandle;

const
  Str: 
string = '123';

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
  GHandle :
= CreateEvent(nil, True, False, PChar(Str));
  Memo1.Lines.Add(IntToStr(GHandle));
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  
try
    GHandle1 :
= OpenEvent(EVENT_ALL_ACCESS, False, PChar(Str));
  
finally
    Memo1.Lines.Add(SysErrorMessage(GetLastError));
  
end;
  Memo1.Lines.Add(IntToStr(GHandle1));
end;

{ TestThread }

procedure TestThread.Execute;
begin
  
inherited;
  I :
= 0;
  Self.FreeOnTerminate :
= False;
  
while not self.Terminated do
  
begin
    WaitForSingleObject(GHandle, INFINITE);
    Synchronize(ShowMsg);
    InterlockedIncrement(I);
  
end;
end;

procedure TestThread.ShowMsg;
begin
  Form1.Memo1.Lines.Add(IntToStr(I));
end;

procedure TForm1.Button3Click(Sender: TObject);
var
  T: TestThread;
begin
  T :
= TestThread.Create(False);
end;

procedure TForm1.Button4Click(Sender: TObject);
begin
  SetEvent(GHandle);
end;

procedure TForm1.Button5Click(Sender: TObject);
begin
  ResetEvent(GHandle);
end;

procedure TForm1.Button6Click(Sender: TObject);
begin
  SetEvent(GHandle1);
end;

procedure TForm1.Button7Click(Sender: TObject);
begin
  ResetEvent(GHandle1)
end;

end.
原文地址:https://www.cnblogs.com/chengxin1982/p/1752515.html