1 Unit uUtils;
 2 
 3 Interface
 4 
 5 Uses Windows, Forms;
 6 
 7 Const
 8   DEFAULT_FOCUSRECT_WIDTH = 3;
 9 
10 var
11   WndOrder: Integer;
12 
13 Type
14   TMsgViewType = (mvtParent, mvtChildren, mvtAllSameThread,
15     mvtAllSameProcess, mvtAll);
16   TMsgViewTypes = Set Of TMsgViewType;
17 
18 Procedure DrawWindowFocusRect(Wnd: HWND;
19   Width: Integer = DEFAULT_FOCUSRECT_WIDTH);
20 Function FindTopmostWindow(ParentWnd: HWND; Pt: TPoint): HWND;
21 
22 Implementation
23 
24 Function FindTopmostWindow(ParentWnd: HWND; Pt: TPoint): HWND;
25 Var
26   R: TRect;
27 Begin
28   Result := GetWindow(ParentWnd, GW_CHILD);
29   // 上等同Result := GetTopWindow(ParentWnd);
30   While Result <> 0 Do
31   Begin
32     GetWindowRect(Result, R);
33     If IsWindowVisible(Result) And PtInRect(R, Pt) Then
34     // PtInRect判断指定的点是否位于矩形lpRect内部
35     Begin
36       If ((Result = Application.MainForm.Handle) Or
37         (Application.MainForm.Handle = GetWindow(Result, GW_OWNER))) Then
38       Begin
39         Result := 0;
40         Exit;
41       End;
42       Result := FindTopmostWindow(Result, Pt);
43       Exit;
44     End;
45     Result := GetWindow(Result, GW_HWNDNEXT);
46   End;
47   Result := ParentWnd;
48 End;
49 
50 Procedure MyDrawFocusRect(DC: HDC; R: TRect;
51   Width: Integer = DEFAULT_FOCUSRECT_WIDTH);
52 Var
53   I: Integer;
54 Begin
55   InflateRect(R, -Width, -Width);
56   DrawFocusRect(DC, R);
57   For I := 1 To Width Do
58   Begin
59     InflateRect(R, 1, 1);
60     SetTextColor(DC, RGB(0, 255, 255)); // 边框颜色
61     DrawFocusRect(DC, R);
62   End;
63 End;
64 
65 Procedure DrawWindowFocusRect(Wnd: HWND;
66   Width: Integer = DEFAULT_FOCUSRECT_WIDTH);
67 Var
68   DC: HDC;
69   R: TRect;
70 Begin
71   DC := getwindowdc(Wnd); //返回hWnd参数所指定的窗口的设备环境,获得的设备环境覆盖了整个窗口（包括非客户区）
72   GetWindowRect(Wnd, R);
73   //该函数把相对于一个窗口的坐标空间的一组点映射成相对于另一窗口的坐标空间的一组点
74   MapWindowPoints(HWND_DESKTOP, Wnd, R, 2);
75    //OffsetRect函数将指定的矩形移动到指定的位置
76   OffsetRect(R, -R.left, -R.top);
77   MyDrawFocusRect(DC, R, Width);
78   releasedc(Wnd, DC);
79 End;
80 
81 End.