• c# ListView 虚拟模式 相关操作


    public class ListViewEx : ListView
    {
    #region 虚拟模式相关操作

    ///<summary>
    /// 前台行集合
    ///</summary>
    public List<ListViewItem> CurrentCacheItemsSource;

    public ListViewEx()
    {
    this.CurrentCacheItemsSource = new List<ListViewItem>();
    this.VirtualMode = true;
    this.RetrieveVirtualItem += new RetrieveVirtualItemEventHandler(listView_RetrieveVirtualItem);
    }

    ///<summary>
    /// 重置listview集合
    ///</summary>
    ///<param name="l"></param>
    public void ReSet(IList<ListViewItem> l)
    {
    this.CurrentCacheItemsSource.Clear();
    this.CurrentCacheItemsSource = new List<ListViewItem>();
    foreach (var item in l)
    {
    this.CurrentCacheItemsSource.Add(item);
    }
    this.VirtualListSize = this.CurrentCacheItemsSource.Count;
    }

    ///<summary>
    /// 虚拟模式事件
    ///</summary>
    ///<param name="sender"></param>
    ///<param name="e"></param>
    private void listView_RetrieveVirtualItem(object sender, RetrieveVirtualItemEventArgs e)
    {
    if (this.CurrentCacheItemsSource == null || this.CurrentCacheItemsSource.Count == 0)
    {
    return;
    }

    ListViewItem lv = this.CurrentCacheItemsSource[e.ItemIndex];
    e.Item = lv;
    }

    ///<summary>
    /// 获取选中的第一行的指定tag值
    ///</summary>
    ///<param name="key"></param>
    ///<returns></returns>
    public string FirstSelectItemValue(string key)
    {
    int i = GetColumnsIndex(key);

    return this.CurrentCacheItemsSource[this.SelectedIndices[0]].SubItems[i].Text;
    }

    ///<summary>
    /// 获取列名的索引
    ///</summary>
    ///<param name="key"></param>
    ///<returns></returns>
    public int GetColumnsIndex(string key)
    {
    int i = 0;
    for (; i < this.Columns.Count; i++)
    {
    if (this.Columns[i].Name == key)
    {
    break;
    }
    }

    return i;
    }

    ///<summary>
    /// 获取选中项
    ///</summary>
    ///<returns></returns>
    public List<ListViewItem> GetSelectItem()
    {
    List<ListViewItem> l = new List<ListViewItem>();
    foreach (var item in this.SelectedIndices)
    {
    l.Add(this.CurrentCacheItemsSource[int.Parse(item.ToString())]);
    }
    return l;
    }

    ///<summary>
    /// 获取选中行的某列集合
    ///</summary>
    ///<param name="key"></param>
    ///<returns></returns>
    public List<string> GetListViewField(string key)
    {
    List<string> ids = new List<string>();

    foreach (var item in this.SelectedIndices)
    {
    string id = this.CurrentCacheItemsSource[int.Parse(item.ToString())].SubItems[GetColumnsIndex(key)].Text;
    ids.Add(id);
    }
    return ids;
    }

    private ListViewItemComparer mySorter;
    ///<summary>
    /// 排序
    ///</summary>
    ///<param name="e"></param>
    protected override void OnColumnClick(ColumnClickEventArgs e)
    {
    base.OnColumnClick(e);

    string dbType = this.Columns[e.Column].Tag.ToString();

    if (this.mySorter == null)
    {
    this.mySorter = new ListViewItemComparer(e.Column, SortOrder.Ascending, dbType);
    }
    else
    {
    if (this.mySorter.SortColumn == e.Column)
    {
    if (this.mySorter.Order == SortOrder.Ascending)
    {
    this.mySorter.Order = SortOrder.Descending;
    }
    else
    {
    this.mySorter.Order = SortOrder.Ascending;
    }
    }
    else
    {
    this.mySorter.SortColumn = e.Column;
    this.mySorter.Order = SortOrder.Ascending;
    }

    this.mySorter.DbType = dbType;

    this.CurrentCacheItemsSource.Sort(this.mySorter);

    this.Invalidate();
    }
    }
    #endregion

    #region 普通模式下排序
    /*普通模式下排序
    public void ReLoadColumn()
    {
    this.ListViewItemSorter = new ListViewItemComparer(0, SortOrder.Ascending, this.Columns[0].Tag.ToString());
    }

    protected override void OnColumnClick(ColumnClickEventArgs e)
    {
    base.OnColumnClick(e);

    string dbType = this.Columns[e.Column].Tag.ToString();


    if (this.ListViewItemSorter == null)
    {
    this.ListViewItemSorter = new ListViewItemComparer(e.Column, SortOrder.Ascending, dbType);
    }
    else
    {
    ListViewItemComparer comparer = this.ListViewItemSorter as ListViewItemComparer;
    if (comparer.SortColumn == e.Column)
    {
    if (comparer.Order == SortOrder.Ascending)
    {
    comparer.Order = SortOrder.Descending;
    }
    else
    {
    comparer.Order = SortOrder.Ascending;
    }
    }
    else
    {
    comparer.SortColumn = e.Column;
    comparer.Order = SortOrder.Ascending;
    }

    //MessageBox.Show(dbType);

    comparer.DbType = dbType;

    //仅仅改变了ListViewItemSorter属性值,这里不会自动调用Sort()方法,需要显式指定执行Sort()方法实现排序。
    this.Sort();
    }
    }
    */
    #endregion

    #region ListView排序逻辑
    ///<summary>
    /// ListView排序逻辑
    ///</summary>
    private class ListViewItemComparer : System.Collections.Generic.IComparer<ListViewItem>
    {
    public string DbType;
    public ListViewItemComparer()
    {
    this.SortColumn = 0;
    this.Order = SortOrder.None;
    }

    public ListViewItemComparer(int column)
    : this()
    {
    this.SortColumn = column;
    }

    ///<summary>
    ///
    ///</summary>
    ///<param name="column">哪列</param>
    ///<param name="sortOrder">排序方式</param>
    ///<param name="dbType">类型</param>
    public ListViewItemComparer(int column, SortOrder sortOrder, string dbType)
    : this(column)
    {
    Order = sortOrder;
    DbType = dbType.ToLower();
    }

    #region IComparer 成员
    public int Compare(ListViewItem x, ListViewItem y)
    {
    int result = 0;
    string c1 = "";
    string c2 = "";

    try
    {
    c1 = x.SubItems[this.SortColumn].Text;
    c2 = y.SubItems[this.SortColumn].Text;
    }
    catch (Exception ex)
    {
    // MessageBox.Show(ex.Message);
    return 0;
    }

    switch (DbType)
    {
    case "int":
    result = Fn.IsInt(c1, 0) - Fn.IsInt(c2, 0);
    break;

    case "datetime":
    DateTime t1 = Fn.IsDate(c1, DateTime.MinValue);
    DateTime t2 = Fn.IsDate(c2, DateTime.MinValue);

    if (DateTime.TryParse(c1, out t1) && DateTime.TryParse(c2, out t2))
    {
    int cha1 = Fn.IsInt((t1 - t2).TotalSeconds.ToString(), 0);
    result = Fn.IsInt((t1 - t2).TotalSeconds.ToString(), 0);

    if (cha1 == 0)
    result = 0;
    else if (cha1 < 0)
    result = -1;
    else
    result = 1;
    }
    else
    {
    result = string.Compare(c1, c2);
    }

    break;

    case "double":
    double d1 = Fn.IsDouble(c1, 0);
    double d2 = Fn.IsDouble(c2, 0);

    if (d1 == d2)
    result = 0;
    else if (d1 < d2)
    result = -1;
    else
    result = 1;
    break;

    default:
    result = string.Compare(c1, c2);
    break;
    }

    if (this.Order == SortOrder.Ascending)
    {
    return result;
    }
    else if (this.Order == SortOrder.Descending)
    {
    return (-result);
    }
    else
    {
    return 0;
    }
    }
    #endregion

    ///<summary>
    /// 当前排序列
    ///</summary>
    public int SortColumn
    {
    get;
    set;
    }

    ///<summary>
    /// 当前列排序方式
    ///</summary>
    public SortOrder Order
    {
    get;
    set;
    }
    }
    #endregion
    }

    主要功能使用方法:

    添加列

    AddLVCol("first", "null", "", 0);
    AddLVCol("id", "int", "", 0);
    AddLVCol("index", "int", "序号", 40);
    AddLVCol("name", "text", "产品名称", 200);
    ...


    protected void AddLVCol(string pName, string pTag, string pText, int pWidth)
    {
    ColumnHeader ch = new ColumnHeader();
    ch.Name = pName;
    ch.Tag = pTag;
    ch.Text = pText;
    ch.Width = pWidth;
    this.listV.Columns.Add(ch);
    }

    添加内容

    List<ListViewItem> listItem = new List<ListViewItem>();
    listItem.Add.....

    this.listV.ReSet(listItem);

    删除内容时选择列id集合

    List<string> idList = this.listV.GetListViewField("id");

    修改内容时获取id

    int id = int.Parse(this.listV.FirstSelectItemValue("id"));

    获当前选中的集合

    List<ListViewItem> listData=this.listV.CurrentCacheItemsSource;





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  • 原文地址:https://www.cnblogs.com/suger/p/2235682.html
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