Question

我有两个这样的课程：

public class Instance
{
    /// <summary>
    /// Identity of index
    /// </summary>
    public int Id { get; set; }

    /// <summary>
    /// Items within this group.
    /// </summary>
    public Dictionary<string, ItemRow> Items;

    public Instance()
    {
        //Items = new Dictionary<string, ItemRow>();
        Items = new Dictionary<string, ItemRow>();
    }
}

public class GroupMemory
{
    /// <summary>
    /// Name of the OPC group
    /// </summary>
    public string Name { get; set; }
    /// <summary>
    /// Scan rate for this group.
    /// </summary>
    public string ScanRate { get; set; }
    /// <summary> 
    /// Number of instances for this group.
    /// </summary>
    public int CountOfInstances { get; set; }

    /// <summary>
    /// Instances within this group.
    /// </summary>
    public Dictionary<int, Instance> Instances;
    /// <summary>
    /// Items within this group.
    /// </summary>
    public Dictionary<string, ItemRow> Items;

    /// <summary>
    /// Constructor of GroupMemory class.
    /// </summary>
    public GroupMemory()
    {
        Items = new Dictionary<string, ItemRow>();
        Instances = new Dictionary<int, Instance>();
    }
}

我有一个listview，我在listview的每个项目中绑定GroupMemory对象。 listview的最后一列是一个ComboBox，我需要在其中绑定groupmemory的每个实例的Id。例如，如果每个组内存包含两个实例，并且实例具有Id = 1和Id = 2，我想在组合框中显示1和2作为其项目。我如何为组合框或其代码behinde编写xaml代码？

这是我的listview的xaml代码

<ListView.View>
            <GridView>
                <GridViewColumn Header="Name" Width="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=ListView}, Converter={StaticResource starWidthConverter}}"  DisplayMemberBinding="{Binding Path=Name}" />
                <GridViewColumn Header="Scan Rate" Width="60" DisplayMemberBinding="{Binding Path=ScanRate}" />
                <GridViewColumn Header="Instances" Width="60" DisplayMemberBinding="{Binding Path=CountOfInstances}" />
                <GridViewColumn Header="Index" Width="100">
                    <GridViewColumn.CellTemplate>
                        <DataTemplate>
                            <ComboBox Width="50" ItemsSource="{Binding Instances}" SelectedValue="{Binding Id}" DisplayMemberPath="Id"/>
                        </DataTemplate>
                    </GridViewColumn.CellTemplate>
                </GridViewColumn>
            </GridView>
        </ListView.View>

Answer 1

假设ComboBox的DataContext是GroupMemory类的实例，您可以尝试将ComboBox的ItemsSource绑定到Instances.Values属性并设置{{ 1}}显示每个DisplayMemberPath的{{1}}：

Id

Answer 2

您的Instances被声明为字段，并且它不是有效的binding source。如果要绑定到属性，则应将其转换为属性。将声明更改为：

public Dictionary<int, Instance> Instances { get; set; }

然后，因为它是Dictionaty<K, V>，并且每个项目都是KeyValuePair<K, V>类型，其中Key是int而Value是您的Instance尝试将DisplayMemberPath更改为Value.Id

<ComboBox ItemsSource="{Binding Instances}" DisplayMemberPath="Value.Id"/>

Answer 3

如果将itemsource绑定到Instances属性，则可以将DisplayMember和/或valuemember绑定到Key或Value。

它相对简单

实例是KeyValuePair，您需要绑定到Value.Id

但是我也注意到你的类都没有实现INotifyPropertyChanged。您需要实现这一点，因为这是Binding知道您的值已更新的方式。

如果你仍然坚持使用字典，你可能还需要查看ObservableDictionary。 http://blogs.microsoft.co.il/shimmy/2010/12/26/observabledictionarylttkey-tvaluegt-c/

在WPF C＃中填充ComboBox项

3 个答案: