双击CListCtrl列分割条调整宽度

ON_NOTIFY(HDN_DIVIDERDBLCLICK, 0, &CXXX::OnHdnDividerdblclickListData)

void CXXX::OnHdnDividerdblclickListData(NMHDR *pNMHDR, LRESULT *pResult)
{
    LPNMHEADER phdr = reinterpret_cast<LPNMHEADER>(pNMHDR);
    
    // TODO: 在此添加控件通知处理程序代码
    int col = phdr->iItem;

    CHeaderCtrl* pHeaderCtrl = m_wndList.GetHeaderCtrl();
    int nColumnCount = pHeaderCtrl->GetItemCount();

    if ((col < 0) || (nColumnCount <= 0) || (col >= nColumnCount))
    {
        return;
    }

    int width = 0;
    //如果是最后一列
    if (col == nColumnCount - 1)
    {
        CDC* pDC = this->GetDC();

        LVCOLUMN lvc = { 0 };
        lvc.mask = LVCF_WIDTH | LVCF_TEXT | LVCF_MINWIDTH | LVCF_DEFAULTWIDTH | LVCF_IDEALWIDTH;
        TCHAR sColText[256] = { 0 };
        lvc.pszText = sColText;
        lvc.cchTextMax = sizeof(sColText) - 1;
        m_wndList.GetColumn(col, &lvc);

        if (lvc.pszText != nullptr)
        {
            width = pDC->GetTextExtent(lvc.pszText).cx;
        }

        for (int i = 0; i < m_wndList.GetItemCount(); ++i)
        {
            int w = pDC->GetTextExtent(m_wndList.GetItemText(i, col)).cx;
            if (w > width)
            {
                width = w;
            }
        }

        this->ReleaseDC(pDC);
    }
    else
    {
        m_wndList.SetColumnWidth(col, LVSCW_AUTOSIZE);
        int nColumnWidth = m_wndList.GetColumnWidth(col);

        m_wndList.SetColumnWidth(col, LVSCW_AUTOSIZE_USEHEADER);
        int nHeaderWidth = m_wndList.GetColumnWidth(col);

        width = max(nColumnWidth, nHeaderWidth);
    }

    width += 10;
    m_wndList.SetColumnWidth(col, width);

    *pResult = 0;
}

当然，也可以实现自己的CListCtrl，此时需要将Message Map稍加改造，这点需要注意！

    ON_NOTIFY(HDN_DIVIDERDBLCLICKA, 0, &CMyListCtrl::OnHdnDividerdblclick)
    ON_NOTIFY(HDN_DIVIDERDBLCLICKW, 0, &CMyListCtrl::OnHdnDividerdblclick)