delphi - Delphi中如何给变量赋值？

Question

下面的 C 代码如何在 Delphi 中完成？我试图翻译，但Delphi似乎不允许这种语法。基本上，我需要将一个函数分配给一个变量，就像在 C 代码中一样。在 Delphi 上如何做到这一点？

这是引用的 C 代码:

void EnumWindowsTopToDown(HWND owner, WNDENUMPROC proc, LPARAM param)
{
    HWND currentWindow = GetTopWindow(owner);
    if (currentWindow == NULL)
        return;
    if ((currentWindow = GetWindow(currentWindow, GW_HWNDLAST)) == NULL)
        return;
    while (proc(currentWindow, param) && (currentWindow = GetWindow(currentWindow, GW_HWNDPREV)) != NULL);
}

这是我的尝试:

type
  TFNWndEnumProc = function(_hwnd: HWND; _lParam: LPARAM): BOOL; stdcall;

    procedure EnumWindowsTopToDown(Owner: HWND; Proc: TFNWndEnumProc;
      _Param: LPARAM);
    var
      CurrentWindow: HWND;
    begin
      CurrentWindow := GetTopWindow(Owner);
      if CurrentWindow = 0 then
        Exit;

      CurrentWindow := GetWindow(CurrentWindow, GW_HWNDLAST);
      if CurrentWindow = 0 then
        Exit;

      while Proc(CurrentWindow, _Param) and (CurrentWindow :=  GetWindow(CurrentWindow, GW_HWNDPREV)) <> 0;
    end;

Answer 1

Delphi 无法像 C/C++ 那样在 while 或 if 语句内分配变量。您需要分解 while 语句，就像在调用 GetWindow(GW_HWNDLAST) 时必须分解 if 语句一样，例如:

type
  TFNWndEnumProc = function(_hwnd: HWND; _lParam: LPARAM): BOOL; stdcall;

procedure EnumWindowsTopToDown(Owner: HWND; Proc: TFNWndEnumProc; Param: LPARAM);
var
  CurrentWindow: HWND;
begin
  CurrentWindow := GetTopWindow(Owner);
  if CurrentWindow = 0 then
    Exit;

  CurrentWindow := GetWindow(CurrentWindow, GW_HWNDLAST);
  if CurrentWindow = 0 then
    Exit;

  while Proc(CurrentWindow, Param) do
  begin
    CurrentWindow := GetWindow(CurrentWindow, GW_HWNDPREV);
    if CurrentWindow = 0 then Exit;
  end;
end;