Question

我在MSDN中找到了ListView排序的解决方案...... 但我发现代码在单击列时需要花费太多时间才能正确显示ListView ... 所以我要求一个解决方案来加快速度。我必须对包含超过10,000个项目的ListView进行排序。这是我的整个代码......

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Collections;
using System.Runtime.InteropServices;

namespace ListViewSorter
{
    class ListViewSorter
    {
        const Int32 HDF_SORTDOWN = 0x200;
        const Int32 HDF_SORTUP = 0x400;
        const Int32 HDI_FORMAT = 0x4;
        const Int32 HDM_GETITEM = 0x120b;
        const Int32 HDM_SETITEM = 0x120c;
        const Int32 LVM_GETHEADER = 0x101f;

        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        static extern IntPtr SendMessage(IntPtr hWnd, UInt32 msg, IntPtr wParam, IntPtr lParam);

        [DllImport("user32.dll", CharSet = CharSet.Auto, EntryPoint = "SendMessage")]
        static extern IntPtr SendMessageLVCOLUMN(IntPtr hWnd, UInt32 msg, IntPtr wParam, ref LVCOLUMN lParam);

        [StructLayout(LayoutKind.Sequential)]
        public struct LVCOLUMN
        {
            public Int32 mask;
            public Int32 cx;
            [MarshalAs(UnmanagedType.LPTStr)]
            public string pszText;
            public IntPtr hbm;
            public Int32 cchTextMax;
            public Int32 fmt;
            public Int32 iSubItem;
            public Int32 iImage;
            public Int32 iOrder;
        }
        public void SetSortIcon( ListView listview, int ColumnIndex)
        {
            IntPtr clmHdr = SendMessage(listview.Handle, LVM_GETHEADER, IntPtr.Zero, IntPtr.Zero);
            SortOrder sorting = listview.Sorting;
            for (int i = 0; i < listview.Columns.Count; i++)
            {
                IntPtr clmPtr = new IntPtr(i);
                LVCOLUMN lvColumn = new LVCOLUMN();

                lvColumn.mask = HDI_FORMAT;
                SendMessageLVCOLUMN(clmHdr, HDM_GETITEM, clmPtr, ref lvColumn);
                if (sorting != SortOrder.None && i == ColumnIndex)
                {
                    if (sorting == SortOrder.Ascending)
                    {
                        lvColumn.fmt &= ~HDF_SORTDOWN;
                        lvColumn.fmt |= HDF_SORTUP;
                    }
                    else
                    {
                        lvColumn.fmt &= ~HDF_SORTUP;
                        lvColumn.fmt |= HDF_SORTDOWN;
                    }
                }
                else
                {
                    lvColumn.fmt &= ~HDF_SORTDOWN & ~HDF_SORTUP;
                }
                SendMessageLVCOLUMN(clmHdr, HDM_SETITEM, clmPtr, ref lvColumn);
            }
        }
        public int SortColumn(ListView listview, int ColumnIndex, int sortColumn)
        {
            if (ColumnIndex != sortColumn)
            {
                sortColumn = ColumnIndex;
                listview.Sorting = SortOrder.Ascending;
            }
            else
            {
                if (listview.Sorting == SortOrder.Ascending)
                    listview.Sorting = SortOrder.Descending;
                else
                    listview.Sorting = SortOrder.Ascending;
            }
            SetSortIcon(listview, sortColumn);
            listview.Sort();
            listview.ListViewItemSorter = new ListViewItemComparer(ColumnIndex,
                                                              listview.Sorting);
            return sortColumn;
        }
    }
    class ListViewItemComparer : IComparer
    {
        private int col;
        private SortOrder order;
        public ListViewItemComparer()
        {
            col = 0;
            order = SortOrder.Ascending;
        }
        public ListViewItemComparer(int column, SortOrder order)
        {
            col = column;
            this.order = order;
        }
        public int Compare(object x, object y)
        {
            int returnVal;
            try
            {
                System.DateTime firstDate =
                        DateTime.Parse(((ListViewItem)x).SubItems[col].Text);
                System.DateTime secondDate =
                        DateTime.Parse(((ListViewItem)y).SubItems[col].Text);
                returnVal = DateTime.Compare(firstDate, secondDate);
            }
            catch
            {
                returnVal = String.Compare(((ListViewItem)x).SubItems[col].Text,
                            ((ListViewItem)y).SubItems[col].Text);
            }
            if (order == SortOrder.Descending)
                returnVal *= -1;
            return returnVal;
        }

    }
}

任何人都可以帮我解决这个问题吗？

Answer 1

现在我想到的一种方法是使用od data-binding并设置VirtualMode http://msdn.microsoft.com/en-us/library/system.windows.forms.listview.virtualmode.aspx。属性true。

这样做可以实现以下目的：

您的大型自定义数据data-layer自定义管理。换句话说，您对数据进行排序，并将其绑定到listview，而不是对listview项进行排序。
listView.VirtualMode=true;会强制listview控制仅为在ui 中显示的项目创建listview项目。换句话说，如果datacollection中有10.000个项目，但在UI上我只能看到其中的15个，由于窗口维度，渲染和lustviewitem ui工件创建时间将仅花费对于15而不是10.000就像你的情况一样。

希望这有帮助。

Answer 2

我认为你应该尝试定义数据类型而不是使用object。迫使编制者弄清楚dt需要额外的时间。

如何更快地排序ListView？

2 个答案: