使用VC++和MFC绘制渐变颜色的线条

class CMyStatic : public CStatic
{
public:
    CMyStatic();

protected:
    DECLARE_MESSAGE_MAP()
public:
    afx_msg void OnPaint();
};

CMyStatic::CMyStatic()
{
}

BEGIN_MESSAGE_MAP(CMyStatic, CStatic)
    ON_WM_PAINT()
END_MESSAGE_MAP()

void CMyStatic::OnPaint()
{
    CPaintDC dc(this); // 用于绘制的设备上下文

    CRect rect;
    GetClientRect(&rect);

    // 创建一个渐变画刷
    CBrush brush;
    brush.CreateSolidBrush(RGB(255, 0, 0)); // 起始颜色为红色
    CBrush* pOldBrush = dc.SelectObject(&brush);

    // 绘制渐变线条
    for (int i = 0; i < rect.Width(); i++)
    {
        int r = 255 - i; // 红色分量逐渐减小
        int g = 0;
        int b = i; // 蓝色分量逐渐增加

        // 设置画笔颜色
        dc.SetDCPenColor(RGB(r, g, b));

        // 绘制线条
        dc.MoveTo(rect.left + i, rect.top);
        dc.LineTo(rect.left + i, rect.bottom);
    }

    // 恢复原来的画刷
    dc.SelectObject(pOldBrush);
}

#include "MyStatic.h"

BOOL CMyDialog::OnInitDialog()
{
    CDialogEx::OnInitDialog();

    // 创建自定义控件
    CMyStatic* pStatic = new CMyStatic();
    pStatic->Create(_T(""), WS_CHILD | WS_VISIBLE, CRect(10, 10, 200, 200), this);

    return TRUE;
}