Question

我创建了一个ListView并将ObservableCollection设置为ItemsSource。

然后，我可以使用int来绑定SelectedIndex，它运行良好。

但是，当我选择时，我不知道如何获取项目的详细信息。

我想获取ObservableCollection，然后将其绑定到TextBlock上显示。

我的TextBlock和ListView是不同的UserControl。 MainWindow中的ViewModel。

所以我想知道如何通过ListView SelectedIndex获取ObservableCollection项目？

或其他解决方法？

THX。

MainWinodw中的ViewModel：

public class TestVM : INotifyPropertyChanged
{
    private int _index;
    public int Index
    {
        get
        {
            return _index;
        }
        set
        {
            _index = value;
            RaisePropertyChanged("Index");
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;
    private void RaisePropertyChanged(String propertyName)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }

    private ObservableCollection<User> _items;
    public ObservableCollection<User> Items
    {
        get
        {
            return _items;
        }
        private set
        {
            _items = value;
            RaisePropertyChanged("Items");
        }
    }

    ObservableCollection<User> _collection;
    public ObservableCollection<User> Collection
    {
        get
        {
            return _collection;
        }
        private set
        {
            _collection = value;
            RaisePropertyChanged("Collection");
        }
    }

    ListCollectionView _groupView;
    public ListCollectionView GroupView
    {
        get
        {
            return _groupView;
        }
        private set
        {
            _groupView = value;
            RaisePropertyChanged("GroupView");
        }
    }

    public TestVM()
    {
        Collection = new ObservableCollection<User>();
        Collection.Add(new User() { Name = "John Doe1", Age = 10, group = "Group 1" });
        Collection.Add(new User() { Name = "Jane Doe2", Age = 20, group = "Group 1" });

        Collection.Add(new User() { Name = "Sammy Doe", Age = 30, group = "Group 2" });
        Collection.Add(new User() { Name = "Sammy Doe1", Age = 40, group = "Group 2" });
        Collection.Add(new User() { Name = "Sammy Doe2", Age = 50, group = "Group 2" });

        Collection.Add(new User() { Name = "Sammy Doe3", Age = 60, group = "Group 3" });
        Collection.Add(new User() { Name = "Sammy Doe4", Age = 70, group = "Group 3" });

        GroupView = new ListCollectionView(Collection);
        GroupView.GroupDescriptions.Add(new PropertyGroupDescription("group"));
    }
}

public class User
{
    public string Name { set; get; }
    public int Age { set; get; }

    public string group { get; set; }
}

UserControl1中的ListView：

<ListView Margin="10" Name="lv" ItemsSource="{Binding GroupView}" SelectedIndex="{Binding Index}">
        <ListView.View>
            <GridView>
                <local:GridViewColumnExt Header="Name" Width="120" DisplayMemberBinding="{Binding Name}"/>
                <local:GridViewColumnExt x:Name="colAge" Header="Age" Width="50">
                    <local:GridViewColumnExt.CellTemplate>
                        <DataTemplate>
                            <Button Content="{Binding Age}"></Button>
                        </DataTemplate>
                    </local:GridViewColumnExt.CellTemplate>
                </local:GridViewColumnExt>
            </GridView>
        </ListView.View>
        <ListView.GroupStyle>
            <GroupStyle ContainerStyle="{StaticResource GroupHeaderStyle}">
            </GroupStyle>
        </ListView.GroupStyle>
    </ListView>

UserControl2中的TextBlock（只想显示项目详细信息）：

<WrapPanel>
    <TextBlock Text="SelectdIndex: "/>
    <TextBlock Text="{Binding Index}" />
</WrapPanel>

MainWindow.xmal

<Grid>
        <Grid.DataContext>
            <local:TestVM/>
        </Grid.DataContext>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="1*"/>
            <ColumnDefinition Width="1*"/>
        </Grid.ColumnDefinitions>
        <local:StepList Grid.Column="0"></local:StepList>
        <local:ItemDetail Grid.Column="1"></local:ItemDetail>
    </Grid>

Answer 1

如果您希望ListView中所选项目的详细信息显示在文本框中，则必须在文本框中设置绑定。

e.g。

Text="{Binding SelectedItem.EnterThePropertyToShowhere, ElementName=EnterTheNameOfyourListViewhere, UpdateSourceTrigger="PropertyChanged"}"

编辑3：好吧忘了我说的话。尝试：

添加到Listview

SelectedItem="{Bindig SelectedUser , UpdateSourceTrigger="PropertyChanged"}"

使用propertychange Notification

向ViewModel添加属性SelectedUser

public User SelectedUser{
     get { return _selectedUser; }
     set
     {
        if (value == _selectedUser) return;
        _selectedUser= value;
        RaisePropertyChanged("SelectedUser");
     }
  }

添加到文本框中：

 Text="{Binding SelectedUser.PropertyWhichShouldShow, UpdateSourceTrigger="PropertyChanged"}"

如何通过ListView SelectedIndex

1 个答案: