禁止拖动对话框方法：
在WM_HITTEST对应的消息处理函数OnNcHitTest中直接返回TRUE， 或者当指向对话框标题栏时，返回客户区的值HTCLIENT
例子：
UINT CWelcomeDlg::OnNcHitTest(CPoint point)
{
// TODO: Add your message handler code here and/or call default
return HTCLIENT;
}
拖动对话框方法：
在WM_HITTEST对应的消息处理函数OnNcHitTest中， 当指向对话框客户区时，返回标题区的值HTCAPTION
例子：
UINT CDlg::OnNcHitTest(CPoint point)
{
// TODO: Add your message handler code here and/or call default
ScreenToClient(&point);
if (point.y >= 0 && point.y <= DLGCAPHIGHT)
{
return HTCAPTION;
}
return CDialog::OnNcHitTest(point);
}
参考资料：
WM_NCHITTEST
The WM_NCHITTEST message is sent to a window when the cursor moves, or when a mouse button is pressed or released. If the mouse is not captured, the message is sent to the window beneath the cursor. Otherwise, the message is sent to the window that has captured the mouse.
A window receives this message through its WindowProc function.
LRESULT CALLBACK WindowProc( HWND hwnd, // handle to window UINT uMsg, // WM_NCHITTEST WPARAM wParam, // not used LPARAM lParam // horizontal and vertical position );
Parameters
- wParam
- This parameter is not used.
- lParam
- The low-order word specifies the x-coordinate of the cursor. The coordinate is relative to the upper-left corner of the screen.
The high-order word specifies the y-coordinate of the cursor. The coordinate is relative to the upper-left corner of the screen.
Return Values
The return value of the DefWindowProc function is one of the following values, indicating the position of the cursor hot spot.
| Value | Location of hot spot |
|---|---|
| HTBORDER | In the border of a window that does not have a sizing border. |
| HTBOTTOM | In the lower-horizontal border of a resizable window (the user can click the mouse to resize the window vertically). |
| HTBOTTOMLEFT | In the lower-left corner of a border of a resizable window (the user can click the mouse to resize the window diagonally). |
| HTBOTTOMRIGHT | In the lower-right corner of a border of a resizable window (the user can click the mouse to resize the window diagonally). |
| HTCAPTION | In a title bar. |
| HTCLIENT | In a client area. |
| HTCLOSE | In a Close button. |
| HTERROR | On the screen background or on a dividing line between windows (same as HTNOWHERE, except that the DefWindowProc function produces a system beep to indicate an error). |
| HTGROWBOX | In a size box (same as HTSIZE). |
| HTHELP | In a Help button. |
| HTHSCROLL | In a horizontal scroll bar. |
| HTLEFT | In the left border of a resizable window (the user can click the mouse to resize the window horizontally). |
| HTMENU | In a menu. |
| HTMAXBUTTON | In a Maximize button. |
| HTMINBUTTON | In a Minimize button. |
| HTNOWHERE | On the screen background or on a dividing line between windows. |
| HTREDUCE | In a Minimize button. |
| HTRIGHT | In the right border of a resizable window (the user can click the mouse to resize the window horizontally). |
| HTSIZE | In a size box (same as HTGROWBOX). |
| HTSYSMENU | In a window menu or in a Close button in a child window. |
| HTTOP | In the upper-horizontal border of a window. |
| HTTOPLEFT | In the upper-left corner of a window border. |
| HTTOPRIGHT | In the upper-right corner of a window border. |
| HTTRANSPARENT | In a window currently covered by another window in the same thread (the message will be sent to underlying windows in the same thread until one of them returns a code that is not HTTRANSPARENT). |
| HTVSCROLL | In the vertical scroll bar. |
| HTZOOM | In a Maximize button. |
CWnd::OnNcHitTest
afx_msg UINT OnNcHitTest( CPoint point );
Return Value
One of the mouse hit-test enumerated values listed below.
Parameters
point
Contains the x- and y-coordinates of the cursor. These coordinates are always screen coordinates.
Remarks
The framework calls this member function for the CWnd object that contains the cursor (or the CWnd object that used the SetCapture member function to capture the mouse input) every time the mouse is moved.
Note This member function is called by the framework to allow your application to handle a Windows message. The parameters passed to your function reflect the parameters received by the framework when the message was received. If you call the base-class implementation of this function, that implementation will use the parameters originally passed with the message and not the parameters you supply to the function.
See Also CWnd::GetCapture, WM_NCHITTEST
Mouse Enumerated Values
- HTBORDER In the border of a window that does not have a sizing border.
- HTBOTTOM In the lower horizontal border of the window.
- HTBOTTOMLEFT In the lower-left corner of the window border.
- HTBOTTOMRIGHT In the lower-right corner of the window border.
- HTCAPTION In a title-bar area.
- HTCLIENT In a client area.
- HTERROR On the screen background or on a dividing line between windows (same as HTNOWHERE except that the DefWndProc Windows function produces a system beep to indicate an error).
- HTGROWBOX In a size box.
- HTHSCROLL In the horizontal scroll bar.
- HTLEFT In the left border of the window.
- HTMAXBUTTON In a Maximize button.
- HTMENU In a menu area.
- HTMINBUTTON In a Minimize button.
- HTNOWHERE On the screen background or on a dividing line between windows.
- HTREDUCE In a Minimize button.
- HTRIGHT In the right border of the window.
- HTSIZE In a size box (same as HTGROWBOX).
- HTSYSMENU In a Control menu or in a Close button in a child window.
- HTTOP In the upper horizontal border of the window.
- HTTOPLEFT In the upper-left corner of the window border.
- HTTOPRIGHT In the upper-right corner of the window border.
- HTTRANSPARENT In a window currently covered by another window.
- HTVSCROLL In the vertical scroll bar.
- HTZOOM In a Maximize button。
转自：CSDN