将分层对象数据绑定到ListBox [英] Binding Hierarchical object data to ListBox

问题描述

我正在尝试使用WPF中的数据绑定用来自对象源的数据填充ListBox.

I'm trying to populate a ListBox with data from an object source using data binding in WPF.

源是一个ObjectDataProvider，其数据是从xml文件中加载的.我读了XML文件，填充了适当的数据结构，然后将ObjectDataProvider的ObjectInstance设置为数据结构.

The source is an ObjectDataProvider whose data is loaded in from an xml file. I read in the XML file, filling in the appropriate data structure, then set the ObjectInstance for the ObjectDataProvider to the data structure.

这是数据结构:

public class Element
{
       public decimal myValue;

       public decimal df_myValue { get { return myValue; } set { this.myValue = value; } }
}

public class BasicSet
{
       public Element[] elementSet;

       public Element[] df_elementSet { get { return elementSet; } set { this.elementSet = value; } }
}

public class DataSet
{
        public BasicSet[] basicSet;

    public BasicSet[] df_basicSet { get { return basicSet; } set { this.basicSet = value; } }
}

这是XAML:

<UserControl.Resources>
    <ResourceDictionary>
        <ObjectDataProvider x:Key="TheData" />

        <DataTemplate x:Key="ElementTemplate">
            <StackPanel>
                <TextBox Text="{Binding, Path=df_myValue}" />
            </StackPanel>
        </DataTemplate>

        <HierarchicalDataTemplate x:Key="ElementSetTemplate" ItemsSource="{Binding Path=df_elementSet}" ItemTemplate="{StaticResource ElementTemplate}">
        </HierarchicalDataTemplate>

    </ResourceDictionary>
</UserControl.Resources>

<Grid>
    <ListBox ItemsSource="{StaticResource TheData}" ItemTemplate="{StaticResource ElementSetTemplate}">
    </ListBox>
</Grid>

以下是xml数据加载位置的代码:

Here is the code-behind where the xml data is being loaded:

    private DataSet m_dataSet;
    private ObjectDataProvider mODP;

    public void LoadXml(EditorContext context, XmlValidator.Context validator, XmlDocument doc)
    {
        mODP = FindResource("TheData") as ObjectDataProvider;

        XmlSerializer xs = new XmlSerializer(typeof(DataSet));
        XmlReader r = new XmlNodeReader(doc.DocumentElement);
        m_dataSet = (DataSet)xs.Deserialize(r);

        mODP.ObjectInstance = m_dataSet;
    }

所需的结果是，列表框将为数据结构中的每个元素都具有一个文本框.注意，出于某种原因，数据结构是分层的.我无法展平数据结构以简化问题.

The desired result is that the ListBox would have a TextBox for each element in the data structure. Note that the data structure is hierarchical for a reason. I cannot flatten the data structure to simplify the problem.

我确定xml数据已正确加载到数据结构中，因为我可以放置一个断点并检查它，并且所有数据看起来都很好.但是，当我运行该程序时，列表框中没有任何显示.

I am certain that the xml data is being loaded correctly into the data structure, because I can place a breakpoint and check it and all the data looks fine. But when I run the program, nothing shows up in the ListBox.

感谢您的帮助.

推荐答案

我发现我做错了什么.有几处错误.这里是要点:

I figured out the things I was doing wrong. There were several things wrong. Here are the main points:

1)我应该一直在使用itemsControl

1) I should have been using an itemsControl

2)我不需要使用HierarchicalDataTemplate

2) I didn't need to use HierarchicalDataTemplate

3)我需要三个级别的控件:itemsControl内的itemsControl内的TextBox ...这可以使用两个DataTemplates来完成.顶级itemsControl指的是一个包含内部ItemsControl的DataTemplate.然后，该itemsControl引用一个包含内部TextBox的DataTemplate.

3) I needed three levels of controls: a TextBox inside an itemsControl inside an itemsControl... and this can be accomplished using two DataTemplates. The top-level itemsControl refers to a DataTemplate that holds an inner itemsControl. That itemsControl then refers to a DataTemplate that holds an inner TextBox.

这是正确的xaml:

<UserControl.Resources>
    <ResourceDictionary>
        <ObjectDataProvider x:Key="TheData" />

        <DataTemplate x:Key="ElementTemplate">
            <TextBox Text="{Binding Path=df_myValue}"/>
        </DataTemplate>

        <DataTemplate x:Key="ElementSetTemplate">
            <GroupBox Header="I am a GroupBox">
                <ItemsControl ItemsSource="{Binding Path=df_elementSet}" ItemTemplate="{StaticResource ElementTemplate}">
                    <ItemsControl.ItemsPanel>
                        <ItemsPanelTemplate>
                            <StackPanel />
                        </ItemsPanelTemplate>
                    </ItemsControl.ItemsPanel>
                </ItemsControl>
            </GroupBox>
        </DataTemplate>

    </ResourceDictionary>
</UserControl.Resources>

<Grid>
    <ItemsControl ItemsSource="{Binding Source={StaticResource TheData}, Path=df_basicSet}" ItemTemplate="{StaticResource ElementSetTemplate}">
        <ItemsControl.ItemsPanel>
            <ItemsPanelTemplate>
                <StackPanel />
            </ItemsPanelTemplate>
        </ItemsControl.ItemsPanel>
    </ItemsControl>
</Grid>

希望这对其他人有帮助...

Hope this helps someone else...

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