Walkthrough: Adding Animation to an MFC Project

บทความ
08/03/2021

This walkthrough teaches how to add a basic animated object to a Visual C++, Microsoft Foundation Class Library (MFC) project.

The walkthrough shows how to accomplish these tasks:

Create an MFC application.
Add a menu and then add commands to start and stop an animation.
Create handlers for the start and stop commands.
Add an animated object to the project.
Center the animated object in the window.
Verify the results.

Note

Your computer might show different names or locations for some of the Visual Studio user interface elements in the following instructions. The Visual Studio edition that you have and the settings that you use determine these elements. For more information, see Personalizing the IDE.

Prerequisites

To complete this walkthrough, you must have Visual Studio.

To create an MFC application

Use the MFC Application Wizard to create an MFC application. See Walkthrough: Using the New MFC Shell Controls for instructions on how to open the wizard for your version of Visual Studio.
In the Name box, type MFCAnimationWalkthrough. Click OK.
In the MFC Application Wizard dialog box, verify that Application Type is Multiple Documents, Project Style is Visual Studio, and the Document/View architecture support option is selected. Click Finish.

On the View menu, point to Other Windows and then click Resource View.
In Resource View, navigate to the Menu folder and open it. Double-click the IDR_MFCAnimationWalkthroughTYPE resource to open it for modification.
On the menu bar, in the Type Here box, type A&nimation to create an Animation menu.
Under Animation, in the Type Here box, type Start &Forward to create a Start Forward command.
Under Start Forward, in the Type Here box, type Start &Backward.
Under Start Backward, in the Type Here box, type S&top to create a Stop command.
Save MFCAnimationWalkthrough.rc and close it.
In Solution Explorer, double-click MainFrm.cpp to open it for modification. In the CMainFrame::OnCreate method, locate the section that has several calls to lstBasicCommands.AddTail. Just after that section, add the following code.
```
lstBasicCommands.AddTail(ID_ANIMATION_STARTFORWARD);
lstBasicCommands.AddTail(ID_ANIMATION_STARTBACKWARD);
lstBasicCommands.AddTail(ID_ANIMATION_STOP);
```
Save the file and close it.

To create handlers for the start and stop commands

On the Project menu, click Class Wizard.
In the MFC Class Wizard, under Class name, select CMFCAnimationWalkthroughView.
On the Commands tab, in the Object IDs box, select ID_ANIMATION_STARTFORWARD, and then in the Messages box, select COMMAND. Click Add Handler.
In the Add Member Function dialog box, click OK.
In the Object IDs box, select ID_ANIMATION_STARTBACKWARD, and then in the Messages box, select COMMAND. Click Add Handler.
In the Add Member Function dialog box, click OK.
In the Object IDs box, select ID_ANIMATION_STOP, and then in the Messages box, select COMMAND. Click Add Handler and then click OK.
In the Add Member Function dialog box, click OK.
In the MFC Class Wizard, click OK.
Save MFCAnimationWalkthroughView.cpp, which is open in the editor, but don't close it.

To add an animated object to the project

In Solution Explorer, double-click MFCAnimationWalkthroughView.h to open it for modification. Just before the definition of the CMFCAnimationWalkthroughView class, add the following code to create a custom animation controller that will handle scheduling conflicts with the animation object.

class CCustomAnimationController : public CAnimationController
{
public:
    CCustomAnimationController()
    {
    }

    virtual BOOL OnHasPriorityTrim(CAnimationGroup* pGroupScheduled,
        CAnimationGroup* pGroupNew,
        UI_ANIMATION_PRIORITY_EFFECT priorityEffect)
    {
        return TRUE;
    }
};

At the end of the CMFCAnimationWalkthroughView class, add the following code.

CCustomAnimationController m_animationController;
CAnimationColor m_animationColor;
CAnimationRect m_animationRect;

After the DECLARE_MESSAGE_MAP() line, add the following code.
```
void Animate(BOOL bDirection);
```
Save the file and close it.
In MFCAnimationWalkthroughView.cpp, at the top of the file after the #include statements but before any class methods, add the following code.
```
static int nAnimationGroup = 0;
static int nInfoAreaHeight = 40;
```

At the end of the constructor for CMFCAnimationWalkthroughView, add the following code.

m_animationController.EnableAnimationTimerEventHandler();
m_animationController.EnablePriorityComparisonHandler(UI_ANIMATION_PHT_TRIM);
m_animationColor = RGB(255, 255, 255);
m_animationRect = CRect(0, 0, 0, 0);
m_animationColor.SetID(-1, nAnimationGroup);
m_animationRect.SetID(-1, nAnimationGroup);
m_animationController.AddAnimationObject(&m_animationColor);
m_animationController.AddAnimationObject(&m_animationRect);

Locate the CAnimationWalthroughView::PreCreateWindow method and then replace it with the following code.

BOOL CMFCAnimationWalkthroughView::PreCreateWindow(CREATESTRUCT& cs)
{
    // TODO: Modify the Window class or styles here by modifying
    //       the CREATESTRUCT cs
    m_animationController.SetRelatedWnd(this);

    return CView::PreCreateWindow(cs);
}

Locate the CAnimationWalkthroughView::OnDraw method and then replace it with the following code.

void CMFCAnimationWalkthroughView::OnDraw(CDC* pDC)
{
    CMFCAnimationWalkthroughDoc* pDoc = GetDocument();
    ASSERT_VALID(pDoc);
    if (!pDoc)
        return;

    // TODO: add draw code for native data here
    CMemDC dcMem(*pDC, this);
    CDC& dc = dcMem.GetDC();
    CRect rect;
    GetClientRect(rect);

    dc.FillSolidRect(rect, GetSysColor(COLOR_WINDOW));

    CString strRGB;
    strRGB.Format(_T("Fill Color is: %d; %d; %d"),
        GetRValue(m_animationColor),
        GetGValue(m_animationColor),
        GetBValue(m_animationColor));

    dc.DrawText(strRGB, rect, DT_CENTER);
    rect.top += nInfoAreaHeight;

    CBrush br;
    br.CreateSolidBrush(m_animationColor);
    CBrush* pBrushOld = dc.SelectObject(&br);

    dc.Rectangle((CRect)m_animationRect);

    dc.SelectObject(pBrushOld);
}

At the end of the file, add the following code.

void CMFCAnimationWalkthroughView::Animate(BOOL bDirection)
{
    static UI_ANIMATION_SECONDS duration = 3;
    static DOUBLE dblSpeed = 35.;
    static BYTE nStartColor = 50;
    static BYTE nEndColor = 255;

    BYTE nRedColorFinal = bDirection ? nStartColor : nEndColor;
    BYTE nGreenColorFinal = bDirection ? nStartColor : nEndColor;
    BYTE nBlueColorFinal = bDirection ? nStartColor : nEndColor;

    CLinearTransition* pRedTransition =
        new CLinearTransition(duration, (DOUBLE)nRedColorFinal);

    CSmoothStopTransition* pGreenTransition =
        new CSmoothStopTransition(duration, (DOUBLE)nGreenColorFinal);

    CLinearTransitionFromSpeed* pBlueTransition =
        new CLinearTransitionFromSpeed(dblSpeed, (DOUBLE)nBlueColorFinal);

    m_animationColor.AddTransition(pRedTransition,
        pGreenTransition,
        pBlueTransition);

    CRect rectClient;
    GetClientRect(rectClient);

    rectClient.top += nInfoAreaHeight;

    int nLeftFinal = bDirection ? rectClient.left : rectClient.CenterPoint().x;
    int nTopFinal = bDirection ? rectClient.top : rectClient.CenterPoint().y;
    int nRightFinal = bDirection ? rectClient.right : rectClient.CenterPoint().x;
    int nBottomFinal = bDirection ? rectClient.bottom : rectClient.CenterPoint().y;

    CLinearTransition* pLeftTransition =
        new CLinearTransition(duration, nLeftFinal);

    CLinearTransition* pTopTransition =
        new CLinearTransition(duration, nTopFinal);

    CLinearTransition* pRightTransition =
        new CLinearTransition(duration, nRightFinal);

    CLinearTransition* pBottomTransition =
        new CLinearTransition(duration, nBottomFinal);

    m_animationRect.AddTransition(pLeftTransition,
        pTopTransition,
        pRightTransition,
        pBottomTransition);

    CBaseKeyFrame* pKeyframeStart =
        CAnimationController::GetKeyframeStoryboardStart();
    CKeyFrame* pKeyFrameEnd =
        m_animationController.CreateKeyframe(nAnimationGroup,
            pBlueTransition);

    pLeftTransition->SetKeyframes(pKeyframeStart, pKeyFrameEnd);
    pTopTransition->SetKeyframes(pKeyframeStart, pKeyFrameEnd);
    pRightTransition->SetKeyframes(pKeyframeStart, pKeyFrameEnd);
    pBottomTransition->SetKeyframes(pKeyframeStart, pKeyFrameEnd);

    m_animationController.AnimateGroup(nAnimationGroup);
}

On the Project menu, click Class Wizard.
In the MFC Class Wizard, under Class name, select CMFCAnimationWalkthroughView.
On the Messages tab, in the Messages box, select WM_ERASEBKGND, click Add Handler, and then click OK.
In MFCAnimationWalkthroughView.cpp, replace the implementation of OnEraseBkgnd with the following code to reduce flickering in the animated object when it's redrawn.
```
BOOL CMFCAnimationWalkthroughView::OnEraseBkgnd(CDC* /*pDC*/)
{
    return TRUE;
}
```

Replace the implementations of CMFCAnimationWalkthroughView::OnAnimationStartforward, CMFCAnimationWalkthroughView::OnAnimationStartbackward, and CMFCAnimationWalkthroughView::OnAnimationStop with the following code.

void CMFCAnimationWalkthroughView::OnAnimationStartforward()
{
    Animate(TRUE);
}

void CMFCAnimationWalkthroughView::OnAnimationStartbackward()
{
    Animate(FALSE);
}

void CMFCAnimationWalkthroughView::OnAnimationStop()
{
    IUIAnimationManager* pManager = m_animationController.GetUIAnimationManager();
    if (pManager != NULL)
    {
        pManager->AbandonAllStoryboards();

    }
}

Save the file and close it.

To center the animated object in the window

In Solution Explorer, double-click MFCAnimationWalkthroughView.h to open it for modification. At the end of the CMFCAnimationWalkthroughView class, just after the definition of m_animationRect, add the following code.
```
BOOL m_bCurrentDirection;
```
Save the file and close it.
On the Project menu, click Class Wizard.
In the MFC Class Wizard, under Class name, select CMFCAnimationWalkthroughView.
On the Messages tab, in the Messages box, select WM_SIZE, click Add Handler, and then click OK.

In MFCAnimationWalkthroughView.cpp, replace the code for CMFCAnimationWalkthroughView::OnSize with the following code.

void CMFCAnimationWalkthroughView::OnSize(UINT nType, int cx, int cy)
{
    CView::OnSize(nType, cx, cy);
    CRect rect;
    GetClientRect(rect);

    rect.top += nInfoAreaHeight;

    CRect rectAnim = m_animationRect;
    m_animationRect = CRect(CPoint(rect.CenterPoint().x - rectAnim.Width() / 2,
    rect.CenterPoint().y - rectAnim.Height() / 2),
    rectAnim.Size());

    if (m_animationController.IsAnimationInProgress())
    {
        Animate(m_bCurrentDirection);
    }
}

At the beginning of the constructor for CMFCAnimationWalkthroughView, add the following code.
```
m_bCurrentDirection = TRUE;
```
At the beginning of the CMFCAnimationWalkthroughView::Animate method, add the following code.
```
m_bCurrentDirection = bDirection;
```
Save the file and close it.

To verify the results

Build and run the application. On the Animation menu, click Start Forward. A rectangle should appear and then fill the center area. When you click Start Backward, the animation should reverse, and when you click Stop, it should stop. The fill color of the rectangle should change as the animation progresses, and the current color should be displayed at the top of the animation window.

แชร์ผ่าน

Walkthrough: Adding Animation to an MFC Project

Prerequisites

To create an MFC application

To add a menu and then add commands to start and stop an animation

To create handlers for the start and stop commands

To add an animated object to the project

To center the animated object in the window

To verify the results

See also

คำติชม

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