用duilib实现一个按住就变化的按钮

在Duilib中，我们可以使用按钮控件（CButtonUI）来实现一个按住就变化的按钮。具体实现步骤如下：

1. 创建一个CButtonUI控件，并设置它的普通状态和按下状态的背景图片。

<Control name="btnChange" class="ButtonUI" pos="100, 100, 100, 40" normalimage="btn_normal.png" hotimage="btn_hot.png" pushedimage="btn_pushed.png" />

2. 在按钮控件的事件处理函数中，监听鼠标按下和松开事件。

class CMyWnd : public CWindowWnd, public INotifyUI
{
public:
    virtual void Notify(TNotifyUI& msg)
    {
        if (msg.sType == _T("click"))
        {
            if (msg.pSender->GetName() == _T("btnChange"))
            {
                // do something
            }
        }
        else if (msg.sType == _T("mouseenter"))
        {
            if (msg.pSender->GetName() == _T("btnChange"))
            {
                msg.pSender->SetBkImage(_T("btn_hot.png"));
            }
        }
        else if (msg.sType == _T("mouseleave"))
        {
            if (msg.pSender->GetName() == _T("btnChange"))
            {
                msg.pSender->SetBkImage(_T("btn_normal.png"));
            }
        }
    }
};

3. 在鼠标进入按钮控件和离开按钮控件时，更改按钮控件的背景图片。

else if (msg.sType == _T("mouseenter"))
{
    if (msg.pSender->GetName() == _T("btnChange"))
    {
        msg.pSender->SetBkImage(_T("btn_hot.png"));
    }
}
else if (msg.sType == _T("mouseleave"))
{
    if (msg.pSender->GetName() == _T("btnChange"))
    {
        msg.pSender->SetBkImage(_T("btn_normal.png"));
    }
}

完整代码示例：

#include <Windows.h>
#include <stdio.h>
#include "UIlib.h"

using namespace DuiLib;

class CMyWnd : public CWindowWnd, public INotifyUI
{
public:
    virtual LPCTSTR GetWindowClassName() const { return _T("DUIMainFrame"); }
    virtual CDuiString GetSkinFile() { return _T("test.xml"); }
    virtual CDuiString GetSkinFolder() { return _T(""); }

    virtual void Notify(TNotifyUI& msg)
    {
        if (msg.sType == _T("click"))
        {
            if (msg.pSender->GetName() == _T("btnChange"))
            {
                // do something
            }
        }
        else if (msg.sType == _T("mouseenter"))
        {
            if (msg.pSender->GetName() == _T("btnChange"))
            {
                msg.pSender->SetBkImage(_T("btn_hot.png"));
            }
        }
        else if (msg.sType == _T("mouseleave"))
        {
            if (msg.pSender->GetName() == _T("btnChange"))
            {
                msg.pSender->SetBkImage(_T("btn_normal.png"));
            }
        }
    }

    virtual LRESULT HandleMessage(UINT uMsg, WPARAM wParam, LPARAM lParam)
    {
        LRESULT lRes = 0;
        BOOL bHandled = TRUE;

        if (uMsg == WM_CREATE)
        {
            m_PaintManager.Init(m_hWnd);
            CDialogBuilder builder;
            CControlUI* pRoot = builder.Create(_T("test.xml"), (UINT)0, NULL, &m_PaintManager);
            ASSERT(pRoot && "Failed to parse XML");
            m_PaintManager.AttachDialog(pRoot);
            m_PaintManager.AddNotifier(this);
            return lRes;
        }
        else if (uMsg == WM_NCACTIVATE)
        {
            if (!::IsIconic(*this)) {
                return (wParam == 0) ? TRUE : FALSE;
            }
        }

        if (m_PaintManager.MessageHandler(uMsg, wParam, lParam, lRes))
            bHandled = TRUE;
        if (!bHandled)
            return CWindowWnd::HandleMessage(uMsg, wParam, lParam);
        return lRes;
    }

protected:
    CPaintManagerUI m_PaintManager;
};

int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE /*hPrevInstance*/, LPSTR /*lpCmdLine*/, int nCmdShow)
{
    HRESULT Hr = ::CoInitialize(NULL);
    if (FAILED(Hr)) return 0;

    CMyWnd* pFrame = new CMyWnd();
    if (pFrame == NULL) return 0;
    pFrame->Create(NULL, _T("Duilib Test"), UI_WNDSTYLE_FRAME, WS_EX_WINDOWEDGE);
    pFrame->CenterWindow();
    pFrame->ShowWindow(true);

    CPaintManagerUI::MessageLoop();

    ::CoUninitialize();
    return 0;
}