delphi中，让程序只运行一次的方法[2]

program MyThreadTest;

uses

Windows

Forms

SysUtils

Messages

Dialogs

Unit in Unitpas {Form}

{$R *res}

var

myMutex

FindHid: HWND;

MoudleName: string;

function EnumWndProc(hwnd: Thandle; param: Cardinal): bool; stdcall;

//由于用于api回调函数请使用windows传统的参数传递方式stdcall

var

ClassName WinMoudleName: string;

WinInstance: THandle;

begin

result := true;

SetLength(ClassName );

GetClassName(hwnd pchar(ClassName) length(ClassName)); //获得当前遍历窗口的类名

ClassName := pchar(ClassName); //在字符串后加结束符确定字符串结束

if UpperCase(ClassName) = UpperCase(TFormClassName) then //比较类名

begin

WinInstance := GetWindowLong(hwnd GWL_HINSTANCE); //获得当前遍历窗口的实例

setlength(WinMoudleName );

//获得当前遍历窗口的程序文件名

GetModuleFileName(WinInstance pchar(WinMoudleName) length(WinMoudleName));

WinMoudleName := pchar(WinMoudleName);

WinMoudleName :=ExtractFileName(WinMoudleName);

//MoudleName为工程全局变量自身程序的文件名

if UpperCase(WinMoudleName) = UpperCase(MoudleName) then

begin

  FindHid := hwnd;//FindHid为工程全局变量保存找到的句炳

  result := false; //找到以后就结束遍历

  end;

end;

end;

begin

// CreateMutex建立互斥对象并且给互斥对象起一个唯一的名字

myMutex := CreateMutex(nil false hkOneCopy);

if WaitForSingleObject(myMutex ) <> wait_TimeOut then

//程序没有被运行过

begin

ApplicationInitialize;

  ApplicationCreateForm(TForm Form);

ApplicationRun;

end else

begin

SetLength(MoudleName );

//获得自己程序文件名

GetModuleFileName(HInstance pchar(MoudleName) length(MoudleName));

MoudleName := pchar(MoudleName);

MoudleName := ExtractFileName(MoudleName);

EnumWindows(@EnumWndProc ); //调用枚举函数

if FindHid <> then

begin

  ShowWindow(FindHidSW_RESTORE);

  SetForegroundWindow(FindHid);

end;

end;

end

[EnumWindows函数使用]

EnumWindows 用来列举屏幕上所有顶层窗口

MSDN

The EnumWindows function enumerates all toplevel windows on the screen by passing the handle to each window

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