当ListView的滚动条到达的WinForms底部检测 [英] Detecting when ListView scrollbar reaches the bottom in WinForms

问题描述

我怎么知道什么时候的WinForms ListView的滚动条到达它的底部？ 当发生这种情况，我想在ListView被填充更多的数据（这是无止境的理论在我的情况）。

How do I know when the WinForms ListView scrollbar reaches it's bottom ? When this happens, I want the listview to be populated with more data (which is endless in theory in my case).

在OnScroll事件让我从上面滚动的价值，但我没有办法知道，如果用户可以在任何进一步的或不滚动的。

The OnScroll event gives me the scroll value from the top, but I have no way of knowing if the user can scroll any further or not.

推荐答案

我找到了答案使用一些code从大ObjectListView code-项目： HTTP：//www.$c$cproject.com/KB/list/ObjectListView的.aspx

I found an answer using some code from the great ObjectListView code-project: http://www.codeproject.com/KB/list/ObjectListView.aspx

调用GetScrollInfo：

call GetScrollInfo:

    private const int SIF_RANGE = 0x0001;
    private const int SIF_PAGE = 0x0002;
    private const int SIF_POS = 0x0004;
    private const int SIF_DISABLENOSCROLL = 0x0008;
    private const int SIF_TRACKPOS = 0x0010;
    private const int SIF_ALL = (SIF_RANGE | SIF_PAGE | SIF_POS | SIF_TRACKPOS);        

    [DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
    public static extern bool GetScrollInfo(IntPtr hWnd, int fnBar, SCROLLINFO scrollInfo);

    public static SCROLLINFO GetFullScrollInfo(ListView lv, bool horizontalBar) {
      int fnBar = (horizontalBar ? SB_HORZ : SB_VERT);

      SCROLLINFO scrollInfo = new SCROLLINFO();
      scrollInfo.fMask = SIF_ALL;
      if (GetScrollInfo(lv.Handle, fnBar, scrollInfo))
        return scrollInfo;
      else
        return null;
    }

这个数据结构：

with this data struct:

    [StructLayout(LayoutKind.Sequential)]
    public class SCROLLINFO
    {
        public int cbSize = Marshal.SizeOf(typeof(NativeMethods.SCROLLINFO));
        public int fMask;
        public int nMin;
        public int nMax;
        public int nPage;
        public int nPos;
        public int nTrackPos;
    }

在nMax分别给出了总的最大滚动值，包括滚动柄本身，所以真正有用的最大值为n最大 - n页面，其中n页面的滚动柄的大小

the nMax gives the total max scroll value including the scroll handle itself, so the actually useful max value is nMax - nPage, where nPage is the size of the scroll handle.

这个伟大的工程！

这篇关于当ListView的滚动条到达的WinForms底部检测的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！