CODEWITHSUNDEEP
wpfc#-4.0
LittleOne
LittleOne

Reputation: 131

WPF -treeview items can't be selected at 4th level when using datatemplate within datatemplate

I tried to implement treeview with 4 levels using WPF/C#.Net 4.0.It loads all 4 levels but can't select 4th level and when selecting 3rd level it select group with 4th level. Continent->Country->District->Artifacts is one structure but there is another one Continent->Products->Artifacts

Resource DataTemplates->

<DataTemplate x:Key="DistrictTemplates">
<StackPanel Orientation="Horizontal">   
<TextBlock Text="{Binding Path=ArtifactName}" />
</StackPanel>
</DataTemplate>

<DataTemplate x:Key="CountryTemplate">
<TreeViewItem ItemsSource="{Binding Path=District}" 
ItemTemplate="  {StaticResource DistrictTemplates}" 
Header="{Binding Path=Code}">           
</TreeViewItem>
</DataTemplate>

TreeView code->

<TreeView Name="treeExplorer" MouseDoubleClick="TreeView_MouseDoubleClick" SelectedItemChanged="treeExplorer_SelectedItemChanged">
 <TreeViewItem Name="tviDefinition" IsExpanded="True" Header="Continent">
<TreeViewItem ItemsSource="{Binding Path=Country}" ItemTemplate="{StaticResource CountryTemplate}" Header="Country" />
</TreeViewItem>
</TreeView>

there are some other treeItems as well.I can't use inline template inside the TreeView.Resources and also im confused if can use this HierarchicalDataTemplate sine i cant call Country.Districts.ArtifactName and got two hierarchies but I can call Country.Districts() and then Districts has code property and using code i can find Artifacts.And im using datatemplates inside usercontrol.resources How would I be able to do this?

Upvotes: 0

Views: 949

Answers (2)

LittleOne
LittleOne

Reputation: 131

Finally I managed to solve this.Thanks Josh and everyone.

Resource DataTemplates->

<DataTemplate x:Key="DistrictTemplates">
<StackPanel Orientation="Horizontal">   
<TextBlock Text="{Binding Path=ArtifactName}" />
</StackPanel>
</DataTemplate>

<HierarchicalDataTemplate x:Key="CountryTemplate" DataType="Continent.Countries" ItemsSource="{Binding Path=District}" ItemTemplate="{StaticResource DistrictTemplates}">
<TextBlock Text="{Binding Path=Code}"/>    
</HierarchicalDataTemplate>

TreeView code->

<TreeView Name="treeExplorer" MouseDoubleClick="TreeView_MouseDoubleClick" SelectedItemChanged="treeExplorer_SelectedItemChanged">
<TreeViewItem Name="tviDefinition" IsExpanded="True" Header="Continent">
<TreeViewItem ItemsSource="{Binding Path=Country}" ItemTemplate="{StaticResource CountryTemplate}" Header="Countries" />
</TreeViewItem>
</TreeView>

Upvotes: 0

Josh
Josh

Reputation: 2975

Here's something I've written that goes 4 levels deep. It's a TreeView which shows HL7 message structure. For a quick background HL7 is a field separated message. You have a message. Each message has a Segment. Each Segment has at least one field. A field could have multiple components. A component can have subcomponents. This tree displays the HL7 message structure, where each level is a part of the HL7 message format.

For example, if there is PID segment in the message the tree would like this:

PID
...PID.1
...PID.2
......PID.2.1
......PID.2.2
......PID.2.3
......PID.2.4
.........PID.2.4.1
.........PID.2.4.2

etc...

Here is the XAML:

     <TreeView x:Name="hl7Structure" ItemsSource="{Binding Path=MessageSegments}" IsEnabled="True">
        <TreeView.Resources>
           <HierarchicalDataTemplate DataType="{x:Type MyNamespace:MessageSegment}" ItemsSource="{Binding Path=Fields}">
              <TextBox x:Name="segmentName" BorderBrush="Transparent" BorderThickness="0" Text="{Binding Path=Name}" FocusVisualStyle="{x:Null}" />
           </HierarchicalDataTemplate>
           <HierarchicalDataTemplate DataType="{x:Type MyNamespace:MessageField}" ItemsSource="{Binding Path=Components}">
              <TextBlock x:Name="fieldName" Text="{Binding Path=Name}" ToolTip="{Binding Path=Info}" />
           </HierarchicalDataTemplate>
           <HierarchicalDataTemplate DataType="{x:Type MyNamespace:MessageComponent}" ItemsSource="{Binding Path=Subcomponents}">
              <TextBlock x:Name="componentName" Text="{Binding Path=Name}" ToolTip="{Binding Path=Info}" />
           </HierarchicalDataTemplate>
           <DataTemplate DataType="{x:Type MyNamespace:MessageSubcomponent}">
              <TextBlock x:Name="subComponentName" Text="{Binding Path=Name}" ToolTip="{Binding Path=Info}" />
           </DataTemplate>
        </TreeView.Resources>
    </TreeView>

Now the explanation of how it works. I have a base object that each HL7 message piece inherits. The ItemsSource of the TreeView is bound to that collection. Since there are 4 levels, where 3 show hierarchy and one that does not, there are 3 HierarchicalDataTemplates and 1 DataTemplate.

Think of it this way...The HL7 Message Segment, Field, and Components are tree nodes because they have children. The HL7 subcomponent is a leaf, because it has none. Each tree node gets a HierarchicalDataTemplate, but each leaf just gets a DataTemplate.

Each of HierarchicalDataTemplates know what object type to display by using the DataType property. Here is where I tell the control, the child type it's displaying. This allows me to use the base type collection and then display all the child types at their appropriate node levels.

Hope this helps.

Upvotes: 2

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