获取窗口边框的宽度和标题栏的高度

方法一(通过 Width、ClientWidth 推算):

---

var
  frame,caption: Integer;
begin
  frame := (Width - ClientWidth) div 2;
  caption := Height - ClientHeight - frame * 2;
  ShowMessageFmt('边框宽: %d; 标题高: %d', [frame,caption]); {边框宽: 4; 标题高: 26}
end;

方法二(用 GetSystemMetrics 函数获取):

---

var
  frame,caption: Integer;
begin
  frame := GetSystemMetrics(SM_CXFRAME);
  caption := GetSystemMetrics(SM_CYCAPTION);
  ShowMessageFmt('边框宽: %d; 标题高: %d', [frame,caption]); {边框宽: 4; 标题高: 26}
end;