有没有人使用水平滚动条中的"scroll arrows"来滚动位置？

Has anyone ever used the "scroll arrows" in the horizontal scroll bar to scroll the positions?

本文关键字：arrows scroll 滚动 位置 没有人 水平 滚动条      更新时间：2023-10-16

我希望使用滚动条两端的滚动箭头来滚动条的位置。众所周知，滚动条不像其他控件那样具有通知，因此我遇到了一个问题。

我的滚动条代码如下-

void CScrollBarExDlg::OnHScroll(UINT nSBCode, UINT nPos, CScrollBar* pScrollBar)
{
    if(nSBCode==SB_THUMBPOSITION)
    {
        if(pScrollBar==&m_Scroll)
        {
            m_Edit=nPos;
            m_Scroll.SetScrollPos(nPos);
        }
    }
    UpdateData(FALSE);

    CDialogEx::OnHScroll(nSBCode, nPos, pScrollBar);
}

您必须稍微修改 MSDN 示例才能使用滚动器控件：

//add to message map
ON_WM_HSCROLL()
//initialize in OnInitDialog
SCROLLINFO info = { sizeof(SCROLLINFO) };
info.nMin = 0;
info.nMax = 100;
info.nPage = 1; 
info.fMask = SIF_ALL;
m_Scroll.SetScrollInfo(&info, TRUE);

如果info.nPage大于 1，则可能会超出范围。添加此行以修复它：

info.nMax += info.nPage - 1;

添加重载：

void CMyDialog::OnHScroll(UINT nSBCode, UINT nPos, CScrollBar* pScrollBar)
{
    CDialog::OnVScroll(nSBCode, nPos, pScrollBar);
    if (pScrollBar == &m_Scroll)
    {
        //get scrollbar information
        SCROLLINFO info;
        m_Scroll.GetScrollInfo(&info, SIF_ALL);
        int pos = info.nPos;
        //calculate the new position of scroll box 
        switch (nSBCode)
        {
        case SB_LEFT: pos = info.nMin; break;
        case SB_RIGHT: pos = info.nMax; break;
        case SB_LINELEFT: pos--; break;
        case SB_LINERIGHT: pos++;  break;
        case SB_PAGELEFT: pos -= info.nPage; break;
        case SB_PAGERIGHT: pos += info.nPage; break;
        case SB_THUMBPOSITION: pos = nPos; break;
        case SB_THUMBTRACK: pos = nPos; break;
        }
        //make sure the new position is within range
        if (pos < info.nMin) pos = info.nMin;
        //adjust the max value, incase we had changed it earlier in OnInitDialog
        int max = info.nMax - info.nPage + 1;
        if (pos > max) pos = max;
        //set the new position
        m_Scroll.SetScrollPos(pos);
    }
}
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