WPF ListView实时分组 [英] WPF ListView Live Grouping

问题描述

我有一个动态分组的列表视图，我用来添加组描述的代码是。

I have a listview with dynamic grouping, the code I use to add group descriptions is .

  PropertyGroupDescription groupDescription = new PropertyGroupDescription("CheckSum");
            view = (CollectionView)CollectionViewSource.GetDefaultView(SourceList);
            if (view != null)
            view.GroupDescriptions.Add(groupDescription);

我想要分组生活，但无法弄清楚如何做到这一点。当我尝试使用相同代码的ICollectionViewLiveShaping时，它什么都不做。

I would like the grouping to be live but have not been able to figure out how to do it. When I try to use ICollectionViewLiveShaping with the same code, it does nothing.

这是我正在使用的值转换器，它是转换的MD5值组成组名称（例如组1，组2）等。它工作正常但经过大量滚动顶部后，列表的顶部和底部扰乱了分组的顺序。

Here is the value converter i am using, it is to convert MD5 values into group names(e.g Group 1, Group 2) etc. It is working fine but after a lot of scrolling top the top and bottom of the list disturbs the order of grouping.

class GroupNameConverter : IValueConverter
    {

        public  int i = 0;
       
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {

        
             if (i <= MainWindow.CheckSums.Count-1)
            {
             
                i++;

                return "Group " + i.ToString();
            }


            else
            {

                i--;

                return "Group " + i.ToString();

            }

        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            return null;
        }

首先分组很好，但在向上和向下滚动后，群组名称会全部乱序。

The grouping is fine at first, but after scrolling up and down the group names get all out of order.

我知道问题可能在值转换器中，但无法弄清楚如何修复它。任何帮助将不胜感激。

I know the problem could be in the value converter but cant figure out how to fix it. Any help will be greatly appreciated.

推荐答案

嗨Waleed，

Hi Waleed,

>>我希望分组能够直播，但还是无法计算如何做到这一点。当我尝试使用相同的
代码的ICollectionViewLiveShaping时，它什么都不做。

根据您的描述和代码，您想使用
ICollectionViewLiveShaping to group in
ListView，但你有一些问题，所以请看看下面的代码：

<Grid DataContext="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=Window}, Path=userview}">
        <ListView Name="lvUsers" ItemsSource="{Binding}">
            <ListView.View>
                <GridView>
                    <GridViewColumn
                        Width="120"
                        DisplayMemberBinding="{Binding Name}"
                        Header="Name" />
                    <GridViewColumn
                        Width="50"
                        DisplayMemberBinding="{Binding Age}"
                        Header="Age" />
                </GridView>
            </ListView.View>

            <ListView.GroupStyle>
                <GroupStyle>
                    <GroupStyle.ContainerStyle>
                        <Style TargetType="{x:Type GroupItem}">
                            <Setter Property="Template">
                                <Setter.Value>
                                    <ControlTemplate>
                                        <Expander IsExpanded="True">
                                            <Expander.Header>
                                                <StackPanel Orientation="Horizontal">
                                                    <TextBlock
                                                        VerticalAlignment="Bottom"
                                                        FontSize="22"
                                                        FontWeight="Bold"
                                                        Foreground="Gray"
                                                        Text="{Binding Name}" />
                                                    <TextBlock
                                                        Margin="10,0,0,0"
                                                        VerticalAlignment="Bottom"
                                                        FontSize="22"
                                                        FontStyle="Italic"
                                                        FontWeight="Bold"
                                                        Foreground="Green"
                                                        Text="{Binding ItemCount}" />
                                                    <TextBlock
                                                        VerticalAlignment="Bottom"
                                                        FontSize="22"
                                                        FontStyle="Italic"
                                                        Foreground="Silver"
                                                        Text=" item(s)" />
                                                </StackPanel>
                                            </Expander.Header>
                                            <ItemsPresenter />
                                        </Expander>
                                    </ControlTemplate>
                                </Setter.Value>
                            </Setter>
                        </Style>
                    </GroupStyle.ContainerStyle>
                </GroupStyle>
            </ListView.GroupStyle>
        </ListView>
    </Grid>

 public partial class Window2 : Window
    {
        public ListCollectionView userview { get; set; }
        public Window2()
        {
            InitializeComponent();
            ObservableCollection<User> items = new ObservableCollection<User>();
            items.Add(new User() { Name = "John Doe", Age = 42, Sex = SexType.Male });
            items.Add(new User() { Name = "Jane Doe", Age = 39, Sex = SexType.Female });
            items.Add(new User() { Name = "Sammy Doe", Age = 13, Sex = SexType.Male });
           

            userview= new ListCollectionView(items);
            userview.IsLiveGrouping = true;
            userview.GroupDescriptions?.Add(new PropertyGroupDescription("Sex"));
            //CollectionView view = (CollectionView)CollectionViewSource.GetDefaultView(lvUsers.ItemsSource);
            //PropertyGroupDescription groupDescription = new PropertyGroupDescription("Sex");
            //view.GroupDescriptions.Add(groupDescription);

           
        }
    }
    public enum SexType { Male, Female };

    public class User:ViewModelBase
    {
        private string _Name;
        public string Name
        {
            get { return _Name; }
            set
            {
                _Name = value;
                RaisePropertyChanged("Name");
            }
        }

        private int _Age;
        public int Age
        {
            get { return _Age; }
            set
            {
                _Age = value;
                RaisePropertyChanged("Age");
            }
        }

        private string _Mail;
        public string Mail
        {
            get { return _Mail; }
            set
            {
                _Mail = value;
                RaisePropertyChanged("Mail");
            }
        }

        private SexType _Sex;
        public SexType Sex
        {
            get { return _Sex; }
            set
            {
                _Sex = value;
                RaisePropertyChanged("Sex");            }
        }
    }

最好的问候，

Cherry

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