Delphi 获取菜单高度、标题栏高度、边框高度函数GetSystemMetrics

项目中需要获取不同分辨率德菜单高度，必应搜索了一下，可以用GetSystemMetrics函数实现，代码如下：欢迎加入Delphi知识局QQ群:32422310

unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.Menus;

type
  TForm1 = class(TForm)
    MainMenu1: TMainMenu;
    N11: TMenuItem;
    N2221: TMenuItem;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
  MenuItemHeight:integer;
begin
  MenuItemHeight:= GetSystemMetrics(SM_CYMENUCHECK);
end;

end.

如果菜单折叠，可用以下代码：

type
  TMenuBarInfo = record
    cbSize: DWORD;
    rcBar: TRect;
    hMenu: HMENU;
    hwndMenu: HWND;
    fBarFocused: Byte;
    fFocused: Byte;
  end;

{$EXTERNALSYM GetMenuBarInfo}
function GetMenuBarInfo(hend: HWND; idObject, idItem: ULONG;
  var pmbi: TMenuBarInfo): BOOL; stdcall;

implementation

function GetMenuBarInfo; external user32 name 'GetMenuBarInfo';

procedure TForm1.Button1Click(Sender: TObject);
var
  MenuHeight: Integer;
  MenuBarInfo: TMenuBarInfo;
begin
  MenuBarInfo.cbSize := SizeOf(MenuBarInfo);
  if GetMenuBarInfo(Handle, OBJID_MENU, 0, MenuBarInfo) then
    MenuHeight := MenuBarInfo.rcBar.Bottom - MenuBarInfo.rcBar.Top
  else
    ...
  ...

end;

或者

procedure TForm1.Button1Click(Sender: TObject);
var
  pm : TTPMParams;
  DisplayPoint : TPoint;
  r: TRect;
begin
  Systemparametersinfo( spi_getworkarea, 0, @r, 0 );
  r.top := r.bottom + 1;
  r.bottom := screen.height;

  DisplayPoint := Point( 699, r.top );
  with pm, pm.rcexclude do
  begin
     Top    := r.top;
     Bottom := r.bottom;
     Left   := 0;
     Right  := screen.width;
     cbSize := SizeOf(pm);
  end;
  TrackPopupMenuEx( PopupMenu1.Handle, TPM_VERTICAL or TPM_HORIZONTAL,  
                    DisplayPoint.x, DisplayPoint.y, Handle, @pm );
end;

该函数也可以用于获取屏幕分辨率

GetSystemMetrics(
 　nIndex: Integer {参数, 详见下表}
 ): Integer;
 
举例 - 获取屏幕分辨率:var
 　cx,cy: Integer;
 begin
 　{通过 GetSystemMetrics 函数获取屏幕分辨率}
 　cx := GetSystemMetrics(SM_CXSCREEN);
 　cy := GetSystemMetrics(SM_CYSCREEN);
 　ShowMessageFmt('Width:%d; Height:%d', [cx,cy]);
 　{通过 Screen 对象获取屏幕分辨率}
 　cx := Screen.Width;
 　cy := Screen.Height;
 　ShowMessageFmt('Width:%d; Height:%d', [cx,cy]);
 end;

procedure TForm1.Button9Click(Sender: TObject);
var
  frameh,captionh,menuh: Integer;
  str:string;
begin
//边框高
  frameh := GetSystemMetrics(SM_CXFRAME);
//标题高
  captionh := GetSystemMetrics(SM_CYCAPTION);
//菜单高
  menuh:=GetSystemMetrics(SM_CYMENU);
  str:=  inttostr( frameh)+' '+inttostr(captionh)+' '+inttostr(menuh) ;
  memo1.text:=str;

end;