本例效果图:



WM_NCHITTEST 消息返回后, 消息的 Result 参数表示了鼠标所在窗口的部位.

窗体设计步骤: 新建工程后, 随便添加一个菜单; 设置窗体的 AutoScroll 属性为 True, 并添加一个 Panel 放在合适的位置, 以让窗口出现滚动条.
unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ExtCtrls, StdCtrls, Menus;

type
  TForm1 = class(TForm)
    Panel1: TPanel;
    MainMenu1: TMainMenu;
    mnuFile: TMenuItem;
  private
    procedure MyMsg(var msg: TWMNCHitTest); message WM_NCHITTEST;
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

const
  arr: array[-2..21] of string = (
    'HTERROR',
    'HTTRANSPARENT',
    'HTNOWHERE',
    'HTCLIENT - 客户区',
    'HTCAPTION - 标题',
    'HTSYSMENU - 系统菜单',
    'HTGROWBOX',
    'HTMENU - 菜单',
    'HTHSCROLL - 水平滚动条',
    'HTVSCROLL - 垂直滚动条',
    'HTMINBUTTON - 最小化按钮',
    'HTMAXBUTTON - 最大化按钮',
    'HTLEFT - 左边界',
    'HTRIG - 右边界',
    'HTTOP - 上边界',
    'HTTOPLEFT - 左上角',
    'HTTOPRIG - 右上角',
    'HTBOTTOM - 下边界',
    'HTBOTTOMLEFT - 左下角',
    'HTBOTTOMRIG - 右下角',
    'HTBORDER',
    'HTOBJECT',
    'HTCLOSE - 关闭按钮',
    'HTHELP');

procedure TForm1.MyMsg(var msg: TWMNCHitTest);
var
  i: Integer;
begin
  Inherited;
  i := msg.Result;
  Text := Format('%d: %s', [i, arr[i]]);
end;

end.

//另附 WM_NCHITTEST 消息中 Result 参数的所有可能值的列表: HTERROR = -2; HTTRANSPARENT = -1; HTNOWHERE = 0; HTCLIENT = 1; HTCAPTION = 2; HTSYSMENU = 3; HTGROWBOX = 4; HTSIZE = HTGROWBOX; HTMENU = 5; HTHSCROLL = 6; HTVSCROLL = 7; HTMINBUTTON = 8; HTMAXBUTTON = 9; HTLEFT = 10; HTRIGHT = 11; HTTOP = 12; HTTOPLEFT = 13; HTTOPRIGHT = 14; HTBOTTOM = 15; HTBOTTOMLEFT = $10; HTBOTTOMRIGHT = 17; HTBORDER = 18; HTREDUCE = HTMINBUTTON; HTZOOM = HTMAXBUTTON; HTSIZEFIRST = HTLEFT; HTSIZELAST = HTBOTTOMRIGHT; HTOBJECT = 19; HTCLOSE = 20; HTHELP = 21;
posted on 2008-04-30 14:56  万一  阅读(9993)  评论(4编辑  收藏  举报