C++-结构体作为形参如何设置默认值?

Question

在设计动画类的时候,有这样一个表示动画执行操作的类,他的构造函数如下:

CAnimJobUI(
        RECT rcSrc,
        float fXtrans,
        float fYtrans,
        float fZtrans,
        float fRotateVecX,
        float fRotateVecY,
        float fRotateVecZ,
        float fRotateAngle,   
        DWORD dwStartTick,
        DWORD dwDuration,
        bool bClip,
        RECT rcClip,
        bool bBeforePaint = false,
        int iAlpha = 0,
        ACTION_ANIM eAction = ACTIONTYPE_FLYIN,
        COLORREF clrBack = CLR_INVALID,
        COLORREF clrKey = CLR_INVALID,
        UITYPE_ANIM eAnimType = UIANIMTYPE_FLAT,
        UINT uMsgCallBack = WM_USER,
        TEXTURE_FORM eTextureForm = TEXTURE_CAPTURE,
        CStdString strImgPath = _T(""));

Answer 1

只给结构体赋值能不能帮它也写个构造函数呢？

Answer 2

提供一种解决方案，供参考。由于没有您的完整代码，所以没有经过编译。

const RECT CAnimJobUI::m_defaultRc= {1,2,3,4};

class CAnimJobUI
{
private:
static const RECT m_defaultRc;
public:
CAnimJobUI(
RECT rcSrc,
float fXtrans,
float fYtrans,
float fZtrans,
float fRotateVecX,
float fRotateVecY,
float fRotateVecZ,
float fRotateAngle,
DWORD dwStartTick,
DWORD dwDuration,
bool bClip,
RECT rcClip = m_defaultRc, //这里设置默认值<---------------------
bool bBeforePaint = false,
int iAlpha = 0,
ACTION_ANIM eAction = ACTIONTYPE_FLYIN,
COLORREF clrBack = CLR_INVALID,
COLORREF clrKey = CLR_INVALID,
UITYPE_ANIM eAnimType = UIANIMTYPE_FLAT,
UINT uMsgCallBack = WM_USER,
TEXTURE_FORM eTextureForm = TEXTURE_CAPTURE,
CStdString strImgPath = _T("")){};
};

Answer 3

个人理解，结构体设置默认值，不是可以放在其构造函数中吗？你只需在构造函数中把需要的默认值赋给每个变量即可。这样即安全又没破坏封装性，