VC水纹特效

我的环境：WIN7 X64 + VS2010

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最近在看易语言的官方教程时（即：《十天学会易语言图解教程》），在：第10章-API应用 中有个水纹特效的例子，

看后觉得很是不错，于是想将其搬到VC中来，无奈教程里面只要一个dll文件：WaterDll.dll

在VC中使用dll时，一般都要有相应的xxx.h头文件和xxx.lib库文件，既然没有头文件和库文件，我只能动态调用了。

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效果截图：

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为了方便动态调用WaterDll.dll，我封装了一个类CWaterWave：

WaterWave.h内容如下：

#pragma once
/************************************************************************/                                 */
/************************************************************************/


class CWaterWave
{
public:
    CWaterWave(void);
    ~CWaterWave(void);
public:

    // 各个参数是什么，没找到官方解释，自己多试几个参数看看效果吧
    int WaterInit(int bitmap);
    int WaterMouseAction(int hdc, int sx, int sy, int mx, int my, int half, int deep);
    int WaterTimer(int hdc, int sx, int sy);

private:

    // 函数原型定义 
    typedef int  (_stdcall *PFN_WaterInit)(int bitmap);
    typedef int  (_stdcall *PFN_WaterMouseAction)(int hdc, int sx, int sy, int mx, int my, int half, int deep);
    typedef int  (_stdcall *PFN_WaterTimer)(int hdc, int sx, int sy);

    // 函数指针 
    PFN_WaterInit m_pfnWaterInit;
    PFN_WaterMouseAction m_pfnWaterMouseAction;
    PFN_WaterTimer m_pfnWaterTimer;

    HMODULE m_hWaterDll;
};

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WaterWave.cpp文件内容如下：

#include "StdAfx.h"
#include "WaterWave.h"


CWaterWave::CWaterWave(void)
{
    m_pfnWaterInit = NULL;
    m_pfnWaterMouseAction = NULL;
    m_pfnWaterTimer = NULL;

    m_hWaterDll = LoadLibrary("WaterDll.dll");
    m_pfnWaterInit = (PFN_WaterInit)GetProcAddress(m_hWaterDll, "WaterInit");
    m_pfnWaterMouseAction = (PFN_WaterMouseAction)GetProcAddress(m_hWaterDll, "WaterMouseAction");;
    m_pfnWaterTimer = (PFN_WaterTimer)GetProcAddress(m_hWaterDll, "WaterTimer");;
}


CWaterWave::~CWaterWave(void)
{
    if (m_hWaterDll != NULL)
    {
        FreeLibrary(m_hWaterDll);
        m_hWaterDll = NULL;
    }
}

int CWaterWave::WaterInit( int bitmap )
{
    if (m_pfnWaterInit ==  NULL)
    {
        return -1;
    }
    return m_pfnWaterInit(bitmap);
}

int CWaterWave::WaterMouseAction( int hdc, int sx, int sy, int mx, int my, int half, int deep )
{
    if (m_pfnWaterMouseAction == NULL)
    {
        return -1;
    }
    return m_pfnWaterMouseAction(hdc, sx, sy, mx, my, half, deep);
}

int CWaterWave::WaterTimer( int hdc, int sx, int sy )
{
    if (m_pfnWaterTimer == NULL)
    {
        return -1;
    }
    return m_pfnWaterTimer(hdc, sx, sy);
}

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封装好了类CWaterWave，在MFC中调用就方便多了，其实WaterDll.dll里面的接口不多，我们只要调用以下3个接口，就可以实现水纹特效了：

WaterInit

WaterMouseAction

WaterTimer

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1. 在我们的对话框头文件WaterWindowDlg.h声明一个对象：

 CWaterWave m_waterWave;

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2. 在 工程的资源中插入一副位图，ID设置为：IDB_BMP_SEA

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3. 在对话框的OnInitDialog函数里面增加以下代码：

// 水纹特效初始化
    int iBitmap = (int)::LoadImage(::GetModuleHandle(NULL), MAKEINTRESOURCE(IDB_BMP_SEA), IMAGE_BITMAP, 0, 0, LR_VGACOLOR);
    if (iBitmap != NULL)
    {
        m_waterWave.WaterInit(iBitmap);
    }

    // 开个定时器来处理水纹
    SetTimer(2015, 10, NULL);

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4. 定时器处理过程代码如下：

// 定时器
void CWaterWindowDlg::OnTimer(UINT_PTR nIDEvent)
{
    // TODO: 在此添加消息处理程序代码和/或调用默认值
    HDC hDCWnd = ::GetDC(this->GetSafeHwnd());
    m_waterWave.WaterTimer((INT)hDCWnd, 0, 0);
    ::ReleaseDC(this->GetSafeHwnd(), hDCWnd);

    CDialogEx::OnTimer(nIDEvent);
}

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5. 处理鼠标在窗体的移动事件，在该事件中显示水纹：

// 鼠标移动事件
void CWaterWindowDlg::OnMouseMove(UINT nFlags, CPoint point)
{
    // TODO: 在此添加消息处理程序代码和/或调用默认值
    HDC hDCWnd = ::GetDC(this->GetSafeHwnd());
    m_waterWave.WaterMouseAction ((INT)hDCWnd, 0, 0, point.x, point.y, 5, 100);
    ::ReleaseDC(this->GetSafeHwnd(), hDCWnd);

    CDialogEx::OnMouseMove(nFlags, point);
}

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