CAnimateCtrl Class
Provides the functionality of the Windows common animation control.
Syntax
class CAnimateCtrl : public CWnd
Members
Public Constructors
| Name | Description |
|---|---|
| CAnimateCtrl::CAnimateCtrl | Constructs a CAnimateCtrl object. |
Public Methods
| Name | Description |
|---|---|
| CAnimateCtrl::Close | Closes the AVI clip. |
| CAnimateCtrl::Create | Creates an animation control and attaches it to a CAnimateCtrl object. |
| CAnimateCtrl::CreateEx | Creates an animation control with the specified Windows extended styles and attaches it to a CAnimateCtrl object. |
| CAnimateCtrl::IsPlaying | Indicates whether an Audio-Video Interleaved (AVI) clip is playing. |
| CAnimateCtrl::Open | Opens an AVI clip from a file or resource and displays the first frame. |
| CAnimateCtrl::Play | Plays the AVI clip without sound. |
| CAnimateCtrl::Seek | Displays a selected single frame of the AVI clip. |
| CAnimateCtrl::Stop | Stops playing the AVI clip. |
Remarks
This control (and therefore the CAnimateCtrl class) is available only to programs running under Windows 95, Windows 98, and Windows NT version 3.51 and later.
An animation control is a rectangular window that displays a clip in AVI (Audio Video Interleaved) format— the standard Windows video/audio format. An AVI clip is a series of bitmap frames, like a movie.
Animation controls can play only simple AVI clips. Specifically, the clips to be played by an animation control must meet the following requirements:
There must be exactly one video stream and it must have at least one frame.
There can be at most two streams in the file (typically the other stream, if present, is an audio stream, although the animation control ignores audio information).
The clip must either be uncompressed or compressed with RLE8 compression.
No palette changes are allowed in the video stream.
You can add the AVI clip to your application as an AVI resource, or it can accompany your application as a separate AVI file.
Because your thread continues executing while the AVI clip is displayed, one common use for an animation control is to indicate system activity during a lengthy operation. For example, the Find dialog box of File Explorer displays a moving magnifying glass as the system searches for a file.
If you create a CAnimateCtrl object within a dialog box or from a dialog resource using the dialog editor, it will be automatically destroyed when the user closes the dialog box.
If you create a CAnimateCtrl object within a window, you may need to destroy it. If you create the CAnimateCtrl object on the stack, it is destroyed automatically. If you create the CAnimateCtrl object on the heap by using the new function, you must call delete on the object to destroy it. If you derive a new class from CAnimateCtrl and allocate any memory in that class, override the CAnimateCtrl destructor to dispose of the allocations.
For more information on using CAnimateCtrl, see Controls and Using CAnimateCtrl.
Inheritance Hierarchy
CAnimateCtrl
Requirements
Header: afxcmn.h
CAnimateCtrl::CAnimateCtrl
Constructs a CAnimateCtrl object.
CAnimateCtrl();
Remarks
You must call the Create member function before you can perform any other operations on the object you create.
Example
// This example creates a secondary thread that implements
// the methods of CAnimateCtrl. The procedure of the thread
// is MyClipThreadProc and the thread was created with the
// code AfxBeginThread( MyClipThreadProc, (LPVOID) pParentWnd).
// The example code creates and initializes an animation control,
// then proceeds to pump messages from the queue until one the
// private messages WM_STOPCLIP, WM_PLAYCLIP, WM_SHOWFIRSTFRAME or
// WM_SHOWLASTFRAME is received. The appropriate action is done for
// these messages. The thread ends when the WM_STOPCLIP is received.
// NOTE: the thread parameter, pParam, is a pointer to a CWnd object
// that will be the parent of the animation control.
#define WM_STOPCLIP WM_USER + 1
#define WM_PLAYCLIP WM_USER + 2
#define WM_SHOWFIRSTFRAME WM_USER + 3
#define WM_SHOWLASTFRAME WM_USER + 4
UINT MyClipThreadProc(LPVOID pParam)
{
// NOTE: pParentWnd is the parent window of the animation control.
CWnd *pParentWnd = (CWnd *)pParam;
CAnimateCtrl cAnimCtrl;
// Create the animation control.
if (!cAnimCtrl.Create(WS_CHILD | WS_VISIBLE | ACS_CENTER,
CRect(10, 10, 100, 100), pParentWnd, 1))
{
return false;
}
// Open the AVI file.
if (!cAnimCtrl.Open(_T("MyAvi.avi")))
{
return false;
}
// Pump message from the queue until the stop play message is received.
MSG msg;
while (GetMessage(&msg, NULL, 0, 0) && (msg.message != WM_STOPCLIP))
{
switch (msg.message)
{
// Start playing from the first frame to the last,
// continuously repeating.
case WM_PLAYCLIP:
if (!cAnimCtrl.Play(0, (UINT)-1, (UINT)-1))
return false;
break;
// Show the first frame.
case WM_SHOWFIRSTFRAME:
if (!cAnimCtrl.Seek(0))
return false;
cAnimCtrl.RedrawWindow();
break;
// Show the last frame.
case WM_SHOWLASTFRAME:
if (!cAnimCtrl.Seek((UINT)-1))
return false;
cAnimCtrl.RedrawWindow();
break;
}
TranslateMessage(&msg);
DispatchMessage(&msg);
}
cAnimCtrl.Stop();
cAnimCtrl.Close();
return true;
}
CAnimateCtrl::Close
Closes the AVI clip that was previously opened in the animation control (if any) and removes it from memory.
BOOL Close();
Return Value
Nonzero if successful; otherwise zero.
Example
See the example for CAnimateCtrl::CAnimateCtrl.
CAnimateCtrl::Create
Creates an animation control and attaches it to a CAnimateCtrl object.
virtual BOOL Create(
DWORD dwStyle,
const RECT& rect,
CWnd* pParentWnd,
UINT nID);
Parameters
dwStyle
Specifies the animation control's style. Apply any combination of the windows styles described in the Remarks section below and the animation control styles described in Animation Control Styles in the Windows SDK.
rect
Specifies the animation control's position and size. It can be either a CRect object or a RECT structure.
pParentWnd
Specifies the animation control's parent window, usually a CDialog. It must not be NULL.
nID
Specifies the animation control's ID.
Return Value
Nonzero if successful; otherwise zero.
Remarks
You construct a CAnimateCtrl in two steps. First, call the constructor, and then call Create, which creates the animation control and attaches it to the CAnimateCtrl object.
Apply the following window styles to an animation control.
WS_CHILD Always
WS_VISIBLE Usually
WS_DISABLED Rarely
If you want to use extended windows styles with your animation control, call CreateEx instead of Create.
In addition to the window styles listed above, you may want to apply one or more of the animation control styles to an animation control. See the Windows SDK for more information on animation control styles.
Example
See the example for CAnimateCtrl::CAnimateCtrl.
CAnimateCtrl::CreateEx
Creates a control (a child window) and associates it with the CAnimateCtrl object.
virtual BOOL CreateEx(
DWORD dwExStyle,
DWORD dwStyle,
const RECT& rect,
CWnd* pParentWnd,
UINT nID);
Parameters
dwExStyle
Specifies the extended style of the control being created. For a list of extended Windows styles, see the dwExStyle parameter for CreateWindowEx in the Windows SDK.
dwStyle
Specifies the animation control's style. Apply any combination of the window and animation control styles described in Animation Control Styles in the Windows SDK.
rect
A reference to a RECT structure describing the size and position of the window to be created, in client coordinates of pParentWnd.
pParentWnd
A pointer to the window that is the control's parent.
nID
The control's child-window ID.
Return Value
Nonzero if successful; otherwise 0.
Remarks
Use CreateEx instead of Create to apply extended Windows styles, specified by the Windows extended style preface WS_EX_.
CAnimateCtrl::IsPlaying
Indicates whether an Audio-Video Interleaved (AVI) clip is playing.
BOOL IsPlaying() const;
Return Value
TRUE if an AVI clip is playing; otherwise, FALSE.
Remarks
This method sends the ACM_ISPLAYING message, which is described in the Windows SDK.
CAnimateCtrl::Open
Call this function to open an AVI clip and display its first frame.
BOOL Open(LPCTSTR lpszFileName);
BOOL Open(UINT nID);
Parameters
lpszFileName
A CString object or a pointer to a null-terminated string that contains either the name of the AVI file or the name of an AVI resource. If this parameter is NULL, the system closes the AVI clip that was previously opened for the animation control, if any.
nID
The AVI resource identifier. If this parameter is NULL, the system closes the AVI clip that was previously opened for the animation control, if any.
Return Value
Nonzero if successful; otherwise zero.
Remarks
The AVI resource is loaded from the module that created the animation control.
Open does not support sound in an AVI clip; you can open only silent AVI clips.
If the animation control has the ACS_AUTOPLAY style, the animation control will automatically start playing the clip immediately after it opens it. It will continue to play the clip in the background while your thread continues executing. When the clip is done playing, it will automatically be repeated.
If the animation control has the ACS_CENTER style, the AVI clip will be centered in the control and the size of the control will not change. If the animation control does not have the ACS_CENTER style, the control will be resized when the AVI clip is opened to the size of the images in the AVI clip. The position of the top left corner of the control will not change, only the size of the control.
If the animation control has the ACS_TRANSPARENT style, the first frame will be drawn using a transparent background rather than the background color specified in the animation clip.
Example
See the example for CAnimateCtrl::CAnimateCtrl.
CAnimateCtrl::Play
Call this function to play an AVI clip in an animation control.
BOOL Play(
UINT nFrom,
UINT nTo,
UINT nRep);
Parameters
nFrom
Zero-based index of the frame where playing begins. Value must be less than 65,536. A value of 0 means begin with the first frame in the AVI clip.
nTo
Zero-based index of the frame where playing ends. Value must be less than 65,536. A value of - 1 means end with the last frame in the AVI clip.
nRep
Number of times to replay the AVI clip. A value of - 1 means replay the file indefinitely.
Return Value
Nonzero if successful; otherwise zero.
Remarks
The animation control will play the clip in the background while your thread continues executing. If the animation control has ACS_TRANSPARENT style, the AVI clip will be played using a transparent background rather than the background color specified in the animation clip.
Example
See the example for CAnimateCtrl::CAnimateCtrl.
CAnimateCtrl::Seek
Call this function to statically display a single frame of your AVI clip.
BOOL Seek(UINT nTo);
Parameters
nTo
Zero-based index of the frame to display. Value must be less than 65,536. A value of 0 means display the first frame in the AVI clip. A value of -1 means display the last frame in the AVI clip.
Return Value
Nonzero if successful; otherwise zero.
Remarks
If the animation control has ACS_TRANSPARENT style, the AVI clip will be drawn using a transparent background rather than the background color specified in the animation clip.
Example
See the example for CAnimateCtrl::CAnimateCtrl.
CAnimateCtrl::Stop
Call this function to stop playing an AVI clip in an animation control.
BOOL Stop();
Return Value
Nonzero if successful; otherwise zero.
Example
See the example for CAnimateCtrl::CAnimateCtrl.