Binding from ItemsSource context

I'm having a problem with the DataContext and the Title. The following works as intended:

 <chartingToolkit:LineSeries Title={Binding TrendDaily.Name} ItemsSource="{Binding TrendDaily.Progress}">
 //...
 </chartingToolkit:LineSeries>

But the Title should contain more information so I'm doing this:

<chartingToolkit:LineSeries ItemsSource="{Binding TrendDaily.Progress}">
  <chartingToolkit:LineSeries.Title>
    <StackPanel Orientation="Horizontal">
      <TextBlock Text="{Binding TrendDaily.Name}"/>
      <TextBlock Text="-test text"/>
    </StackPanel>
  </chartingToolkit:LineSeries.Title>
  //...
</chartingToolkit:LineSeries>

I figured out the Title binding doesn't work because it has the "Progress" elements as his context but I wasn't able to find a working binding.

Edit: The complete new code with binding error (Cannot find source for binding with reference 'ElementName=LineName'):

<Window x:Class="WpfApplication1.MainWindow"
    xmlns:chartingToolkit="clr-namespace:System.Windows.Controls.DataVisualization.Charting;assembly=System.Windows.Controls.DataVisualization.Toolkit"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">
<chartingToolkit:Chart Title="Trend">
    <chartingToolkit:Chart.Series>            
        <chartingToolkit:LineSeries DataContext="{Binding TrendDaily}"
ItemsSource="{Binding Progress}" DependentValuePath="Value" IndependentValuePath="Key" x:Name="LineName">
            <chartingToolkit:LineSeries.Title>
                <TextBlock>
                            <Run Text="{Binding DataContext.Name, ElementName=LineName}"/>
                            <Run Text="*"/>                                
                </TextBlock>
            </chartingToolkit:LineSeries.Title>                
        </chartingToolkit:LineSeries>
    </chartingToolkit:Chart.Series>
</chartingToolkit:Chart>
</Window>

Code Behind:

public partial class MainWindow : Window
{
    public TrendDailyClass TrendDaily { get; set; }

    public MainWindow()
    {
        TrendDaily = new TrendDailyClass();
        DataContext = this;
        InitializeComponent();
    }
}

public class TrendDailyClass
{
    public Dictionary<string, double> Progress { get; set; }
    public string Name { get; set; }
    public TrendDailyClass()
    {
        Progress = new Dictionary<string, double>();
        Progres开发者_Python百科s.Add("10", 10);
        Progress.Add("20", 20);
        Name = "test";
    }
}

---

Bind TrendDaily to the DataContext of LineSeries, then use DataContext in the inner bindings, using ElementName as:

<chartingToolkit:Chart Title="Trend"
                     DataContext="{Binding TrendDaily}"
                     x:Name="LineName">
   <chartingToolkit:LineSeries ItemsSource="{Binding Progress}">
     <chartingToolkit:LineSeries.Title>
       <StackPanel Orientation="Horizontal">
        <TextBlock Text="{Binding DataContext.Name, ElementName=LineName}"/>
        <TextBlock Text="-test text"/>
       </StackPanel>
     </chartingToolkit:LineSeries.Title>
     //...
  </chartingToolkit:LineSeries>

Moreover, there is no need to use two TextBlock.. You can use Run (which is very lightweight class) as:

    <StackPanel Orientation="Horizontal">
       <TextBlock>
          <Run Text="{Binding DataContext.Name, ElementName=LineName}"/>
          <Run Text="-test text"/>
       </TextBlock>
    </StackPanel>

It's better, as it avoids unnecessary visual element. Classes derived from UIElement are relatively heavier.

---

If you're first code example is working, you should be able to use the StringFormat property in your first binding:

<chartingToolkit:LineSeries Title={Binding TrendDaily.Name, StringFormat='{}{0}-test text'} ItemsSource="{Binding TrendDaily.Progress}">
//...
</chartingToolkit:LineSeries>