C# 筛选多列ListView C WPF

我想用多列和多个过滤器过滤我的ListView，但我不知道如何

这是我的想法：一个窗口显示当前选定的 列标题，您可以在下拉列表中选择=或>，然后根据您的条件进行筛选，我只找到一列的解决方案，但不知道如何进行多重筛选

数据加载：

var xdoc = XDocument.Load(@"C:\temp\webTsl.xml");
                var units = from u in xdoc.Descendants("sl")
                            select new
                            {
                                EQNr = (string)u.Element("id"),
                                //EQCore = (string)u.Element(""),
                                ArtNr = (string)u.Element("artNr"),
                                Bez = (string)u.Element("bez"),
                                //KundenBez = (string)u.Element(""),
                                //ProjektNr = (string)u.Element(""),
                                //LiefDat = (DateTime)u.Element(""),
                                //EqStart = (DateTime)u.Element(""),
                                //GewaehrStart = (DateTime)u.Element(""),
                                //GewaehrEnde = (DateTime)u.Element("")
                            };

                foreach (var unit in units)
                {
                    items.Add(new Anlagen(unit.EQNr, unit.ArtNr, unit.Bez));
                }


            ListViewAnlagen.ItemsSource = CollectionViewSource.GetDefaultView(items); 

类别：

 public virtual string EQNr { get; set; }
        //public virtual string EQCore { get; set; }
        public virtual string ArtNr { get; set; }
        public virtual string Bez { get; set; }
        //public virtual string KundenBez { get; set; }
        //public virtual string ProjektNr { get; set; }
        //public virtual DateTime? LiefDat { get; set; }
        //public virtual DateTime? EqStart { get; set; }


        //public virtual DateTime? GewaehrStart { get; set; }
        //public virtual DateTime? GewaehrEnde { get; set; }

        public Anlagen(string eqNr,string artNr, string bez) /*, DateTime liefdat, DateTime inbetnahme,DateTime garantiestart,DateTime garantieende*/
        {
            this.EQNr = eqNr;
            //this.EQCore = eqCore;
            this.ArtNr = artNr;
            this.Bez = bez;
            //this.KundenBez = kundenBez;
            //this.ProjektNr = projektNr;
            //this.LiefDat = liefDat;
            //this.EqStart = eqStart;
            //this.GewaehrStart = gewaehrStart;
            //this.GewaehrEnde = gewaehrEnde;

        }

        public Anlagen()
        {
    }

---

基本上，您需要一个过滤器定义，其中传递项目，并使用特定于列的过滤器函数确定项目是否满足过滤器的要求

假设您有一个过滤器界面，如下所示：

public interface IFilterBase<TItem>
{
    PropertyInfo Property { get; } // can be used to display the property name etc.

    bool ApplyFilter(T value);
}

为了使MVVM准备好过滤项集合，我在我的一个项目中使用了以下帮助器类：

public class ObservableLinq<TIn, TOut> : IEnumerable<TOut>, INotifyCollectionChanged
{
    private ObservableCollection<TIn> _Source;
    private Func<IEnumerable<TIn>, IEnumerable<TOut>> _Transformation;

    public ObservableLinq(ObservableCollection<TIn> source, Func<IEnumerable<TIn>, IEnumerable<TOut>> transformation)
    {
        _Source = source;
        _Transformation = transformation;
        _Source.CollectionChanged += Source_CollectionChanged;
    }

    public ObservableLinq(IEnumerable<TIn> source, Func<IEnumerable<TIn>, IEnumerable<TOut>> transformation)
        : this(source as ObservableCollection<TIn> ?? new ObservableCollection<TIn>(source), transformation)
    {
    }

    private void Source_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        RaiseCollectionChanged();
    }

    public IEnumerator<TOut> GetEnumerator()
    {
        return _Transformation(_Source).GetEnumerator();
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        return GetEnumerator();
    }


    // could be a property as well, but this empathizes, that the source collection is not the primary functionality here
    public ObservableCollection<TIn> GetSourceCollection()
    {
        return _Source;
    }


    public event NotifyCollectionChangedEventHandler CollectionChanged;

    protected void RaiseCollectionChanged()
    {
        var handler = CollectionChanged;
        if (handler != null)
        {
            // always reset as it would be pretty complicated to track the actual changes across all the linq thingies
            handler(this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
        }
    }

    /// <summary>
    /// Call when a filter relevant property changed on source collection entries
    /// </summary>
    public void CollectionChangedNeeded()
    {
        RaiseCollectionChanged();
    }
}

---

我觉得这种方法比WPF提供的控件的内置过滤器功能更灵活。基于正则表达式的过滤器，自定义属性类型的过滤器。。。所有这些都是可能的，每种类型的过滤器都不费吹灰之力。只是过滤基础设施的初始设置并不是很简单。

我可以问你一个例子吗？先生，我试图理解你的解决方案，但我真的不明白，你可以举个例子吗？也许我可以稍后再写，而不是现在。。。从代码片段中可以看到，一个现成的示例需要几行代码和xaml。

ObservableCollection<IFilterBase<TItem>> Filters;

source.Where(item => Filters.All(filter => filter.ApplyFilter(item)))

public class ObservableLinq<TIn, TOut> : IEnumerable<TOut>, INotifyCollectionChanged
{
    private ObservableCollection<TIn> _Source;
    private Func<IEnumerable<TIn>, IEnumerable<TOut>> _Transformation;

    public ObservableLinq(ObservableCollection<TIn> source, Func<IEnumerable<TIn>, IEnumerable<TOut>> transformation)
    {
        _Source = source;
        _Transformation = transformation;
        _Source.CollectionChanged += Source_CollectionChanged;
    }

    public ObservableLinq(IEnumerable<TIn> source, Func<IEnumerable<TIn>, IEnumerable<TOut>> transformation)
        : this(source as ObservableCollection<TIn> ?? new ObservableCollection<TIn>(source), transformation)
    {
    }

    private void Source_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        RaiseCollectionChanged();
    }

    public IEnumerator<TOut> GetEnumerator()
    {
        return _Transformation(_Source).GetEnumerator();
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        return GetEnumerator();
    }


    // could be a property as well, but this empathizes, that the source collection is not the primary functionality here
    public ObservableCollection<TIn> GetSourceCollection()
    {
        return _Source;
    }


    public event NotifyCollectionChangedEventHandler CollectionChanged;

    protected void RaiseCollectionChanged()
    {
        var handler = CollectionChanged;
        if (handler != null)
        {
            // always reset as it would be pretty complicated to track the actual changes across all the linq thingies
            handler(this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
        }
    }

    /// <summary>
    /// Call when a filter relevant property changed on source collection entries
    /// </summary>
    public void CollectionChangedNeeded()
    {
        RaiseCollectionChanged();
    }
}

public ObservableLinq<TItem, TItem> FilteredItems { get {...} set {...} }

// init:
FilteredItems = new ObservableLinq<TItem, TItem>(ItemsList, source.Where(item => Filters.All(filter => filter.ApplyFilter(item))));

FilteredItems.CollectionChangedNeeded();