The FindWindow function retrieves a handle to the top-level window whose class name and window name match the specified strings. This function does not search child windows. This function does not perform a case-sensitive search.
To search child windows, beginning with a specified child window, use the FindWindowEx function.
lpClassName [in] Pointer to a null-terminated string that specifies the class name or a class atom created by a previous call to the RegisterClass or RegisterClassEx function. The atom must be in the low-order word of lpClassName; the high-order word must be zero. If lpClassName points to a string, it specifies the window class name. The class name can be any name registered with RegisterClass or RegisterClassEx, or any of the predefined control-class names.
If lpClassName is NULL, it finds any window whose title matches the lpWindowName parameter.
lpWindowName [in] Pointer to a null-terminated string that specifies the window name (the window's title). If this parameter is NULL, all window names match. Return Value
If the function succeeds, the return value is a handle to the window that has the specified class name and window name.
If the function fails, the return value is NULL. To get extended error information, call GetLastError.
The GetWindowThreadProcessId function retrieves the identifier of the thread that created the specified window and, optionally, the identifier of the process that created the window.
hWnd [in] Handle to the window. lpdwProcessId [out] Pointer to a variable that receives the process identifier. If this parameter is not NULL, GetWindowThreadProcessId copies the identifier of the process to the variable; otherwise, it does not. Return Value
The return value is the identifier of the thread that created the window.
Delphi代码：
var
thwnd :Thandle ; //声明变量 窗口句柄
pid:Thandle; //进程句柄
begin
thWnd := FindWindow(nil,'*****'); //得窗口句柄。
GetWindowThreadProcessId(thwnd,@pid);//得进程ID放到pid变量。
end;
