title: WPF TreeView Items not selectable
body: <p>I am currently writing an Folder Browser Dialog in WPF. For displaying the Tree I use an TreeView:</p>
  
  <pre><code>&lt;TreeView Name="FolderView" ItemsSource="{Binding DataTrees}" Grid.Row="0"&gt;
      &lt;TreeView.ItemTemplate&gt;
        &lt;HierarchicalDataTemplate ItemsSource="{Binding Tree}"&gt;
        &lt;TreeViewItem IsSelected="{Binding IsSelected, Mode=TwoWay}" IsExpanded="{Binding IsExpanded, Mode=TwoWay}" Header="{Binding Name}" HorizontalAlignment="Left"/&gt;
        &lt;/HierarchicalDataTemplate&gt;
      &lt;/TreeView.ItemTemplate&gt;
    &lt;/TreeView&gt;
  </code></pre>
  
  <p>Currently I have three Problems: </p>
  
  <ol>
  <li>You can't select an Item in the running Programm</li>
  <li>The Header is about two tabs to the right (not critical but ugly)</li>
  <li>'IsExpanded' is only set when double clicking an item and not on clicking [+] </li>
  </ol>
  
  <p>I don't know where the Problem is so please comment and I will update my Question!</p>
  
  <p>EDIT:
  The Itemsource is a List 
  Data Tree Class:</p>
  
  <pre><code>public class DataTree:INotifyPropertyChanged
  {
    private string path;
  
    private string name;
  
    private ObservableCollection&lt;DataTree&gt; tree;
  
    private bool isSelected;
  
    private bool isExpanded;
  }
  </code></pre>
  
  <p>(simple Code - Without Propertys and Implementation Of INotifyPropertyChanged)</p>