在Directshow中,我们可以对render指定显示窗口,在写程序的过程中, 发现通过put_Owner设置的显示窗口存在自动刷新问题,譬如窗口被遮挡然后再次露出时,被遮挡部分不能自动刷新,需要拖动窗口进行刷新。
网上搜索了一下,找到了解决问题的办法:
http://blog.csdn.net/lemon_wei/archive/2008/02/29/2132195.aspx
具体处理方法:
假设图象窗口的picture控件id为IDC_FRAME_VIEW,
pViewWindon 为 IVideoWindow*接口,作四步处理
1、修改显示控件属性
CWnd* pWnd = GetDlgItem(IDC_FRAME_VIEW);
pWnd->ModifyStyle(0, WS_CLIPCHILDREN);
2、设置为子窗口的句柄
CWnd* pWnd = GetDlgItem(IDC_FRAME_VIEW);
put_Owner((OAHWND)pWnd->GetSafeHwnd( ))
3、OnPaint 不用动
4、OnEraseBkgnd 加如下代码
RECT rect;
CWnd* pWnd = GetDlgItem(IDC_FRAME_VIEW);
pWnd->GetWindowRect(&rect);
ScreenToClient(&rect);
pDC-> ExcludeClipRect(&rect);
return CDialog::OnEraseBkgnd(pDC);
其中的 ModifyStyle 中第二个参数dwstyle
[c-sharp] view plaincopy
- WS_BORDER
- Creates a window that has a thin-line border.
- WS_CAPTION
- Creates a window that has a title bar (includes the WS_BORDER style).
- WS_CHILD
- Creates a child window. A window with this style cannot have a menu bar. This style cannot be used with the WS_POPUP style.
- WS_CHILDWINDOW
- Same as the WS_CHILD style.
- WS_CLIPCHILDREN
- Excludes the area occupied by child windows when drawing occurs within the parent window. This style is used when creating the parent window.
- WS_CLIPSIBLINGS
- Clips child windows relative to each other; that is, when a particular child window receives a WM_PAINT message, the WS_CLIPSIBLINGS style clips all other overlapping child windows out of the region of the child window to be updated. If WS_CLIPSIBLINGS is not specified and child windows overlap, it is possible, when drawing within the client area of a child window, to draw within the client area of a neighboring child window.
- WS_DISABLED
- Creates a window that is initially disabled. A disabled window cannot receive input from the user. To change this after a window has been created, use EnableWindow.
- WS_DLGFRAME
- Creates a window that has a border of a style typically used with dialog boxes. A window with this style cannot have a title bar.
- WS_GROUP
- Specifies the first control of a group of controls. The group consists of this first control and all controls defined after it, up to the next control with the WS_GROUP style. The first control in each group usually has the WS_TABSTOP style so that the user can move from group to group. The user can subsequently change the keyboard focus from one control in the group to the next control in the group by using the direction keys.
- You can turn this style on and off to change dialog box navigation. To change this style after a window has been created, use SetWindowLong.
- WS_HSCROLL
- Creates a window that has a horizontal scroll bar.
- WS_ICONIC
- Creates a window that is initially minimized. Same as the WS_MINIMIZE style.
- WS_MAXIMIZE
- Creates a window that is initially maximized.
- WS_MAXIMIZEBOX
- Creates a window that has a maximize button. Cannot be combined with the WS_EX_CONTEXTHELP style. The WS_SYSMENU style must also be specified.
- WS_MINIMIZE
- Creates a window that is initially minimized. Same as the WS_ICONIC style.
- WS_MINIMIZEBOX
- Creates a window that has a minimize button. Cannot be combined with the WS_EX_CONTEXTHELP style. The WS_SYSMENU style must also be specified.
- WS_OVERLAPPED
- Creates an overlapped window. An overlapped window has a title bar and a border. Same as the WS_TILED style.
- WS_OVERLAPPEDWINDOW
- Creates an overlapped window with the WS_OVERLAPPED, WS_CAPTION, WS_SYSMENU, WS_THICKFRAME, WS_MINIMIZEBOX, and WS_MAXIMIZEBOX styles. Same as the WS_TILEDWINDOW style.
- WS_POPUP
- Creates a pop-up window. This style cannot be used with the WS_CHILD style.
- WS_POPUPWINDOW
- Creates a pop-up window with WS_BORDER, WS_POPUP, and WS_SYSMENU styles. The WS_CAPTION and WS_POPUPWINDOW styles must be combined to make the window menu visible.
- WS_SIZEBOX
- Creates a window that has a sizing border. Same as the WS_THICKFRAME style.
- WS_SYSMENU
- Creates a window that has a window menu on its title bar. The WS_CAPTION style must also be specified.
- WS_TABSTOP
- Specifies a control that can receive the keyboard focus when the user presses the TAB key. Pressing the TAB key changes the keyboard focus to the next control with the WS_TABSTOP style.
- You can turn this style on and off to change dialog box navigation. To change this style after a window has been created, use SetWindowLong.
- WS_THICKFRAME
- Creates a window that has a sizing border. Same as the WS_SIZEBOX style.
- WS_TILED
- Creates an overlapped window. An overlapped window has a title bar and a border. Same as the WS_OVERLAPPED style.
- WS_TILEDWINDOW
- Creates an overlapped window with the WS_OVERLAPPED, WS_CAPTION, WS_SYSMENU, WS_THICKFRAME, WS_MINIMIZEBOX, and WS_MAXIMIZEBOX styles. Same as the WS_OVERLAPPEDWINDOW style.
- WS_VISIBLE
- Creates a window that is initially visible.
- This style can be turned on and off by using ShowWindow or SetWindowPos.
- WS_VSCROLL
- Creates a window that has a vertical scroll bar.