delphi中,让程序只运行一次的方法(2)
program MyThreadTest;
uses
Windows,
Forms,
SysUtils,
Messages,
Dialogs,
Unit1 in 'Unit1.pas' {Form1},
{$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, 100);
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(TForm1.ClassName) then //比较类名
begin
WinInstance := GetWindowLong(hwnd, GWL_HINSTANCE); //获得当前遍历窗口的实例
setlength(WinMoudleName, 100);
//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的名字
myMutex := CreateMutex(nil, false, 'hkOneCopy');
if WaitForSingleObject(myMutex, 0) <> wait_TimeOut then
//程序没有被运行过
begin
Application.Initialize;
Application.CreateForm(TForm1, Form1);
Application.Run;
end else
begin
SetLength(MoudleName, 100);
//获得自己程序文件名
GetModuleFileName(HInstance, pchar(MoudleName), length(MoudleName));
MoudleName := pchar(MoudleName);
MoudleName := ExtractFileName(MoudleName);
EnumWindows(@EnumWndProc, 0); //调用枚举函数
if FindHid <> 0 then
begin
ShowWindow(FindHid,SW_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 top-level windows on the screen by passing the handle to each window。
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