Bind a VM to different views, depending on VM's properties - c#

Now I have the following code:
ViewModel(s)
public class VMBase
{
public string TabID{get;set;}
public string TabHeader {get;set;}
}
public class VM1:VMBase //implements the properties in base class
{
}
public class VM2:VMBase //implements the properties in base class
{
}
And in my DataTemplate.xaml, I have the different local controls binded to the ViewModel, depending on the type of ViewModel it is, ie:
<DataTemplate DataType="{x:Type VM:VM1}">
<local: Control1 />
</DataTemplate>
<DataTemplate DataType="{x:Type VM:VM2}">
<local: Control2 />
</DataTemplate>
Control1 and Control2 are different types of UserControl:
public class Control1:UserControl
{
}
public class Control2:UserControl
{
}
Things are still manageable when I have only two derived classes for VMBase, but what if I have ten? Or more? It's going to get ugly.
Is it possible to bind a single VM to different views ( user control), so that I don't have to manually create so many derived class for VMBase? I will just need to specify the VM properties such as TabID and TabHeader, correct views will be bind as a result.
Edit:
Here are further details: my VM is bind to a ContentControl (ie: contentcontrol.Content=VM). And each VM has two properties TabID and Header. Whether the DataTemplateSelector should be invoked depends on whether it has a specific TabID ( if it has other TabID then this DataTemplateSelector shouldn't be invoked), and which DataTemplate ( the logic inside the DataTemplateSelector ) to invoke depends further on the Header. How to implement this?

Updated answer - v2 (as per question edit)
I think simply returning a null in your DataTemplateSelector when TabID is not a match should do the trick, as WPF will then try and pick the next best match (i.e. the template that matches the DataType). In case the TabID is a match, you can return the template based on the TabHeader value.
So your custom DataTemplateSelector would look like this:
public class TabHeaderDataTemplateSelector : DataTemplateSelector
{
public override DataTemplate SelectTemplate(object item, DependencyObject container)
{
var element = container as FrameworkElement;
if (element == null)
return null;
var viewModel = item as VMBase;
if (viewModel == null || viewModel.TabID != "02")
return null; //continue only if TabID is a match
if (viewModel != null)
{
switch(viewModel.TabHeader)
{
case "two":
return element.FindResource($"Template2") as DataTemplate;
case "three":
return element.FindResource($"Template3") as DataTemplate;
}
}
return null;
}
}
Sample XAML
<Window.Resources>
<!-- data template for VM1 -->
<DataTemplate DataType="{x:Type local:VM1}">
<Grid>
<Rectangle Stroke="Black" />
<TextBlock Margin="5" Text="{Binding TabHeader}" FontSize="18"/>
</Grid>
</DataTemplate>
<!-- data template for VM2 -->
<DataTemplate DataType="{x:Type local:VM2}">
<Grid>
<Rectangle Stroke="Red" />
<TextBlock Margin="5" Text="{Binding TabHeader}" FontSize="18"/>
</Grid>
</DataTemplate>
<DataTemplate x:Key="Template2">
<Grid>
<Ellipse Stroke="Green" StrokeThickness="4"/>
<TextBlock Margin="10" Text="{Binding TabHeader}" FontSize="24"
Foreground="Red" FontWeight="Bold"
HorizontalAlignment="Center" VerticalAlignment="Center" />
</Grid>
</DataTemplate>
<DataTemplate x:Key="Template3">
<Grid>
<TextBlock Margin="10" Text="{Binding TabHeader}" FontSize="24"
Foreground="White" Background="Black" FontWeight="Bold"
HorizontalAlignment="Center" VerticalAlignment="Center" />
</Grid>
</DataTemplate>
<Style TargetType="ContentControl">
<Setter Property="ContentTemplateSelector">
<Setter.Value>
<local:TabHeaderDataTemplateSelector />
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<StackPanel Margin="25">
<ContentControl Content="{Binding VmObj_1}" />
<ContentControl Content="{Binding VmObj_2}" />
<ContentControl Content="{Binding VmObj_3}" />
<ContentControl Content="{Binding VmObj_4}" />
</StackPanel>
and the code-behind
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
this.DataContext = new
{
VmObj_1 = new VM1 { TabID = "01", TabHeader = "one" },
VmObj_2 = new VM1 { TabID = "02", TabHeader = "two" },
VmObj_3 = new VM2 { TabID = "02", TabHeader = "three" },
VmObj_4 = new VM2 { TabID = "03", TabHeader = "four" },
};
}
}
public class VMBase
{
public string TabID { get; set; }
public string TabHeader { get; set; }
}
public class VM1 : VMBase { }
public class VM2 : VMBase { }
Updated answer - v1
You can approach this problem in two different ways. Each option has its own set of pros and cons; but my most recommended approach would be (as #jon-stødle suggested) is to use a DataTemplateSelector
Option 1 - Use DataTemplateSelector
As you are using Type based data-template(s) - then I assume you are most probably using a ContentControl (or a variant) to display the dynamic view-model driven UI. ContentControl and other templated controls such as Label, UserControl, ItemsControl, ListBox etc. usually have dependency property like ContentTemplateSelector or ItemTemplateSelector that you can bind your template-selector to.
You can refer this link for an example for using Label with DataTemplateSelector; or following example for usage with TabControl
XAML:
<Window.Resources>
<DataTemplate x:Key="Tab1Template">
<Grid>
<Rectangle Stroke="Black" />
<TextBlock Margin="5" Text="{Binding}" FontSize="18"/>
</Grid>
</DataTemplate>
<DataTemplate x:Key="Tab2Template">
<Grid>
<Ellipse Stroke="Green" StrokeThickness="4"/>
<TextBlock Margin="10" Text="{Binding}" FontSize="24"
Foreground="Red" FontWeight="Bold"
HorizontalAlignment="Center" VerticalAlignment="Center" />
</Grid>
</DataTemplate>
<DataTemplate x:Key="Tab3Template">
<Grid>
<TextBlock Margin="10" Text="{Binding}" FontSize="24"
Foreground="White" Background="Black" FontWeight="Bold"
HorizontalAlignment="Center" VerticalAlignment="Center" />
</Grid>
</DataTemplate>
<Style TargetType="{x:Type TabControl}">
<Setter Property="ContentTemplateSelector">
<Setter.Value>
<local:TabIdDataTemplateSelector />
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<TabControl>
<TabControl.ItemsSource>
<col:ArrayList>
<sys:String>1</sys:String>
<sys:String>2</sys:String>
<sys:String>3</sys:String>
</col:ArrayList>
</TabControl.ItemsSource>
</TabControl>
DataTemplateSelector:
public class TabIdDataTemplateSelector : DataTemplateSelector
{
public override DataTemplate SelectTemplate(object item, DependencyObject container)
{
var element = container as FrameworkElement;
if (element == null)
return null;
//var vm = item as VMBase;
//var id = vm.TabId;
string id = item as string;
if (id != null)
{
return element.FindResource($"Tab{id}Template") as DataTemplate;
}
return null;
}
}
Option 2 - Use Style based data-triggers
Another option is use data-trigger(s) on the property (i.e. TabId) of your ViewModel to update the ContentTemplate of your container-view (i.e. TabControl).
<Window.Resources>
<DataTemplate x:Key="Tab1Template">
<Grid>
<Rectangle Stroke="Black" />
<TextBlock Margin="5" Text="{Binding Key}" FontSize="18"/>
</Grid>
</DataTemplate>
<DataTemplate x:Key="Tab2Template">
<Grid>
<Ellipse Stroke="Green" StrokeThickness="4"/>
<TextBlock Margin="10" Text="{Binding Key}" FontSize="24"
Foreground="Red" FontWeight="Bold"
HorizontalAlignment="Center" VerticalAlignment="Center" />
</Grid>
</DataTemplate>
<DataTemplate x:Key="Tab3Template">
<Grid>
<TextBlock Margin="10" Text="{Binding Key}" FontSize="24"
Foreground="White" Background="Black" FontWeight="Bold"
HorizontalAlignment="Center" VerticalAlignment="Center" />
</Grid>
</DataTemplate>
<Style TargetType="{x:Type TabControl}">
<Style.Triggers>
<DataTrigger Binding="{Binding TabId}" Value="1">
<Setter Property="ContentTemplate" Value="{StaticResource ResourceKey=Tab1Template}" />
</DataTrigger>
<DataTrigger Binding="{Binding TabId}" Value="2">
<Setter Property="ContentTemplate" Value="{StaticResource ResourceKey=Tab2Template}" />
</DataTrigger>
<DataTrigger Binding="{Binding TabId}" Value="3">
<Setter Property="ContentTemplate" Value="{StaticResource ResourceKey=Tab3Template}" />
</DataTrigger>
</Style.Triggers>
</Style>
</Window.Resources>
<TabControl DisplayMemberPath="Value" SelectedValuePath="Key"
SelectedValue="{Binding TabId}">
<TabControl.ItemsSource>
<col:Hashtable>
<sys:String x:Key="1">one</sys:String>
<sys:String x:Key="2">two</sys:String>
<sys:String x:Key="3">three</sys:String>
</col:Hashtable>
</TabControl.ItemsSource>
</TabControl>

What you are looking for is a DataTemplateSelector. It let's you choose a DataTemplate based on different criteria.
public class TaskListDataTemplateSelector : DataTemplateSelector
{
public override DataTemplate SelectTemplate(object item, DependencyObject container)
{
var element = container as FrameworkElement;
var vmBase = item as VMBase;
if (element != null && vmBase != null)
{
switch(vmBase.TabID)
{
case "Tab1": return element.FindResource("Tab1Template") as DataTemplate;
case "Tab2": return element.FindResource("Tab2Template") as DataTemplate;
default: return null;
}
}
}
}
You can read more about them in the docs or have a look at this tutorial.

Related

WPF binding to UserControl from Page

I have a UWP application, and it has a page containing a few textbox controls bound to A.B.C[2].D, A.B.C[2].E, A.B.C[2].F, and so on
Now I want to move the text boxes to a separate UserControl to simplify my page's XAML but
still want them to be bound to A.B.C[2].D, A.B.C[2].E etc.
How can I achieve this?
Thank you
Here is my UserControl
<UserControl
x:Class="Inspecto.HWStatusDisplayControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:Truphase360"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
d:DesignHeight="300"
d:DesignWidth="250">
<Grid>
<Grid.Resources>
<Style x:Key="styleTxtBox" TargetType="TextBox">
<Setter Property="IsReadOnly" Value="True" />
<Setter Property="Width" Value="75"/>
</Style>
<Style x:Key="styleTxtBlk" TargetType="TextBlock">
<Setter Property="FontSize" Value="12" />
<Setter Property="Margin" Value="10"/>
<Setter Property="Width" Value="75" />
</Style>
</Grid.Resources>
<StackPanel Orientation="Vertical" Margin="20">
<TextBlock Text="{x:Bind Header}" FontSize="16" FontWeight="Bold" Margin="10">
</TextBlock>
<StackPanel Orientation="Horizontal">
<TextBlock Text="Temp1" Style="{StaticResource styleTxtBlk}" />
<TextBox Style="{StaticResource styleTxtBox}" Text="{Binding Mode=OneWay, Path=Temperature1 }" />
</StackPanel>
<StackPanel Orientation="Horizontal">
<TextBlock Text="Temp2" Style="{StaticResource styleTxtBlk}" />
<TextBox Style="{StaticResource styleTxtBox}" Text="{Binding Mode=OneWay, Path=Temperature2 }" />
</StackPanel>
<StackPanel Orientation="Horizontal">
<TextBlock Text="SW Version" Style="{StaticResource styleTxtBlk}" />
<TextBox Style="{StaticResource styleTxtBox}" Text="{Binding Mode=OneWay, Path=SWVersionStr }" />
</StackPanel>
<StackPanel Orientation="Horizontal">
<TextBlock Text="HW Version" Style="{StaticResource styleTxtBlk}" />
<TextBox Style="{StaticResource styleTxtBox}" Text="{Binding Mode=OneWay, Path=HWVersionStr }" />
</StackPanel>
</StackPanel>
</Grid>
</UserControl>
The code block directly under exists inside a page and is repeated multiple times.
The TextBoxs' were bound to {x:Bind ViewModel.DeviceData.Status.Devices[0].Temperature1 } and so on inside the Page
Now I want to display the same from UserControl.
In the data object, the instance of Devices[] is replaced every few seconds. The new array was created by deserializing from JSON object and directly assigned to like
ViewModel.DeviceData.Status.Devices = FromJSON(string);
Thank you
I agree with #EldHasp. The solution for your scenario is that you might need to create a custom dependency property in the UserControl. Then pass the A.B.C object to this property of the UserControl via binding.
I've made a simple demo about this, you could take look at the code and adjust it for your scenario.
UserControl XAML
<Grid x:Name="MyGrid">
<Grid.Resources>
<Style x:Key="styleTxtBox" TargetType="TextBox">
<Setter Property="IsReadOnly" Value="True" />
<Setter Property="Width" Value="75"/>
</Style>
<Style x:Key="styleTxtBlk" TargetType="TextBlock">
<Setter Property="FontSize" Value="12" />
<Setter Property="Margin" Value="10"/>
<Setter Property="Width" Value="75" />
</Style>
</Grid.Resources>
<StackPanel Orientation="Vertical" Margin="20">
<TextBlock Text="{x:Bind Header}" FontSize="16" FontWeight="Bold" Margin="10">
</TextBlock>
<StackPanel Orientation="Horizontal">
<TextBlock Text="Temp1" Style="{StaticResource styleTxtBlk}" />
<TextBox Style="{StaticResource styleTxtBox}" Text="{Binding MyDependencyProperty._List[0].Name}" />
</StackPanel>
</StackPanel>
</Grid>
UserControl Code
public AClass MyDependencyProperty
{
get { return (AClass)GetValue(MyDependencyPropertyProperty); }
set { SetValue(MyDependencyPropertyProperty, value); }
}
// Using a DependencyProperty as the backing store for MyDependencyProperty. This enables animation, styling, binding, etc...
public static readonly DependencyProperty MyDependencyPropertyProperty =
DependencyProperty.Register("MyDependencyProperty", typeof(AClass), typeof(TestUserControl), new PropertyMetadata(null));
public string Header = "TestHeader";
public TestUserControl()
{
this.InitializeComponent();
this.DataContext = this;
}
MainPage Xaml
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<TextBlock Grid.Row="0" Foreground="Red" Text="{x:Bind ViewModel._AClass._List[1].Name}"/>
<local:TestUserControl Grid.Row="1" MyDependencyProperty="{x:Bind ViewModel._AClass}"/>
</Grid>
MainPage Code
public sealed partial class MainPage : Page
{
public TestViewModel ViewModel { get; set; }
public MainPage()
{
this.InitializeComponent();
ViewModel= new TestViewModel();
}
}
public class TestViewModel
{
public AClass _AClass { get; set; }
public TestViewModel()
{
_AClass = new AClass();
}
}
public class AClass
{
public List<BClass> _List { get; set; }
public AClass()
{
_List = new List<BClass>();
_List.Add(new BClass { Name = "123" });
_List.Add(new BClass { Name = "234" });
}
}
public class BClass
{
public string Name { get; set; }
}
And the result:

Multiple DataTemplates for one ListBox

Imagine multiple object types in one Listbox. Both have different look and presented information. If I add any of them in ObservableCollection it displays them fine in ListBox.
<DataTemplate DataType="{x:Type local:DogData}" >
<Grid...
</DataTemplate>
<DataTemplate DataType="{x:Type local:CatData}" >
<Grid...
</DataTemplate>
Now I want users to be able to press a button and switch view to see more detailed information and there templates which provide it
<DataTemplate x:Key="TemplateDogDataWithImages" >
<Grid...
</DataTemplate>
<DataTemplate x:Key="TemplateCatDataWithImages" >
<Grid...
</DataTemplate>
but I can assign only one
AnimalsListBox.ItemTemplate = this.Resources["TemplateDogDataWithImages"] as DataTemplate;
I don't want to have one and have a bunch of triggers in it.
I have researched DataTemplateSelectors
http://tech.pro/tutorial/807/wpf-tutorial-how-to-use-a-datatemplateselector
Is there a better way? Is there a way to switch default templates for each data type so I could avoid DataTemplateSelectors?
On click of the button how do I select TemplateDogDataWithImages and TemplateCatDataWithImages as default ones and cliking other button use TemplateDogDataSimple and TemplateCatDataSimple?
I think a selector is easier (less code), but if you really want to use triggers, maybe something like this?
namespace WpfApplication65
{
public abstract class NotifyBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected void NotifyPropertyChanged(string property)
{
if(PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(property));
}
}
}
public abstract class DataBase : NotifyBase
{
bool m_showDetailed;
public bool ShowDetailed
{
get { return m_showDetailed; }
set
{
m_showDetailed = value;
NotifyPropertyChanged("ShowDetailed");
}
}
}
public class DogData : DataBase { }
public class CatData : DataBase { }
public partial class MainWindow : Window
{
public List<DataBase> Items { get; private set; }
public MainWindow()
{
Items = new List<DataBase>() { new DogData(), new CatData(), new DogData() };
DataContext = this;
InitializeComponent();
}
}
}
<Window x:Class="WpfApplication65.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:l="clr-namespace:WpfApplication65"
Title="MainWindow"
WindowStartupLocation="CenterScreen">
<Window.Resources>
<DataTemplate DataType="{x:Type l:CatData}">
<DataTemplate.Resources>
<DataTemplate x:Key="basic">
<TextBlock Text="This is the basic cat view" />
</DataTemplate>
<DataTemplate x:Key="detailed">
<TextBlock Text="This is the detailed cat view" />
</DataTemplate>
</DataTemplate.Resources>
<Border BorderThickness="1"
BorderBrush="Red"
Margin="2"
Padding="2">
<StackPanel>
<ContentPresenter Name="PART_Presenter"
ContentTemplate="{StaticResource basic}" />
<CheckBox Content="Show Details"
IsChecked="{Binding ShowDetailed}" />
</StackPanel>
</Border>
<DataTemplate.Triggers>
<DataTrigger Binding="{Binding ShowDetailed}"
Value="True">
<Setter TargetName="PART_Presenter"
Property="ContentTemplate"
Value="{StaticResource detailed}" />
</DataTrigger>
</DataTemplate.Triggers>
</DataTemplate>
<DataTemplate DataType="{x:Type l:DogData}">
<DataTemplate.Resources>
<DataTemplate x:Key="basic">
<TextBlock Text="This is the basic dog view" />
</DataTemplate>
<DataTemplate x:Key="detailed">
<TextBlock Text="This is the detailed dog view" />
</DataTemplate>
</DataTemplate.Resources>
<Border BorderThickness="1"
BorderBrush="Blue"
Margin="2"
Padding="2">
<StackPanel>
<ContentPresenter Name="PART_Presenter"
ContentTemplate="{StaticResource basic}" />
<CheckBox Content="Show Details"
IsChecked="{Binding ShowDetailed}" />
</StackPanel>
</Border>
<DataTemplate.Triggers>
<DataTrigger Binding="{Binding ShowDetailed}"
Value="True">
<Setter TargetName="PART_Presenter"
Property="ContentTemplate"
Value="{StaticResource detailed}" />
</DataTrigger>
</DataTemplate.Triggers>
</DataTemplate>
</Window.Resources>
<ListBox ItemsSource="{Binding Items}" />
</Window>

Retrieve View info from DataTemplateSelector

maybe this is a trivial question for many of you...
My app has a TabControl defined as:
<TabControl ItemsSource="{Binding Tabs}" SelectedItem="{Binding SelectedTab}">
<!--Bind the SelectionChanged event of the tab-->
<i:Interaction.Triggers>
<i:EventTrigger EventName="SelectionChanged">
<i:InvokeCommandAction Command="{Binding SelectedChangedCommand}" />
</i:EventTrigger>
</i:Interaction.Triggers>
<!--This is How tab will look-->
<TabControl.ItemTemplate>
<DataTemplate>
<DockPanel>
<Button Name="BtnCloseTab"
DockPanel.Dock="Right"
Margin="5,0,0,0"
Padding="0"
Command="{Binding RelativeSource=
{RelativeSource FindAncestor, AncestorType={x:Type TabControl}},
Path=DataContext.CloseTabCommand}">
<Image Source="/EurocomCPS;component/Images/closeTab.png" Height="11" Width="11"></Image>
</Button>
<TextBlock Text="{Binding Header}" />
</DockPanel>
</DataTemplate>
</TabControl.ItemTemplate>
<!--This will be the content for the tab control-->
<TabControl.ContentTemplate>
<DataTemplate>
<ContentControl
ContentTemplateSelector="{StaticResource TemplateSelector}"
Content="{Binding}" />
</DataTemplate>
</TabControl.ContentTemplate>
</TabControl>
In the window ViewModel I have the following prop:
private ObservableCollection<Tab> _Tabs;
public CPSViewModel()
{
_Tabs = new ObservableCollection<Tab>();
}
public ObservableCollection<Tab> Tabs
{
get { return _Tabs;}
private set
{
_Tabs = value;
this.RaisePropertyChanged("Tabs");
}
}
Now, when a new Tab is created, the following DataTemplateSelector is called:
class TemplateSelector : DataTemplateSelector
{
public override DataTemplate SelectTemplate(object item, DependencyObject container)
{
if (item != null)
{
string templateFile = string.Format("Templates/{0}",
Properties.Settings.Default.AppId + ".tmpl");
if (File.Exists(templateFile))
{
FileStream fs = new FileStream(templateFile, FileMode.Open);
DataTemplate template = XamlReader.Load(fs) as DataTemplate;
return template;
}
}
return null;
}
}
The DataTemplate is based on the XmlDataProvider and here I need to "inform" the Template which xml file it has to load because it is different for every tab:
<DataTemplate
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<DataTemplate.Resources>
<local:StringToBoolConverter x:Key="StringToBoolConverter" />
<local:StringToIntConverter x:Key="StringToIntConverter" />
<XmlDataProvider x:Key="dataProvider" XPath="func/parametri/param/BLOCKS"/>
</DataTemplate.Resources>
<Grid>
.... controls ....
</Grid>
</DataTemplate>
Is there a way to do it?
EDIT
Substantially what I have to do is to have access to my Tab class into the TemplateSelector.
Regards,
Daniele.
if you could define your tabs like
public class TabFirst:ITab {}
public class TabSecond:ITab {}
public class TabBlup:ITab {}
viewmodel
public ObservableCollection<ITab> Tabs
{
get { return _Tabs;}
private set
{
_Tabs = value;
this.RaisePropertyChanged("Tabs");
}
}
you could get rid of the DataTemplateSelector and just definfe your datatemplates in your resources
<DataTemplate DataType="{x:Type local:TabFirst}">
<view:TabFirstView />
<DataTemplate/>
<DataTemplate DataType="{x:Type local:TabSecond}">
<view:TabSecondView />
<DataTemplate/>
and your content control would be just
<TabControl.ContentTemplate>
<DataTemplate>
<ContentControl Content="{Binding}" />
</DataTemplate>
</TabControl.ContentTemplate>

Updating a ListBox with different Content On Button Clicks in WPF

So I have a listbox and a tool bar in my WPF app. The tool bar just has regular controls, and the listbox has vertical expanders.
I need the listbox to have a different set of expanders depending on what button is clicked. Right now it looks like such:
<ListBox>
<local:Select_Analysis_Panel/>
</ListBox>
Where local:Select_Analysis_Panel is seperate user control file containing the expanders. What is the best way to go about dynamically updating the ListBox control's content upon a button click?
For the last couple hours I've been trying to use set DataTemplates for each expander set and bind the to the items control property with little avail with the code below. I'm just trying to get basic framework laid out before setting up a MVVM interface. Later on I was going to replace the ItemsSource="Network_anal" with you know ItemsSource="{Binding WhatExpanderViewModelProperty}" or something like that.
<ListBox Width="250" Margin="5,0,0,0">
<ListBox.Resources>
<DataTemplate DataType="Select_Analysis_Panel">
<local:Select_Analysis_Panel/>
</DataTemplate>
<DataTemplate x:Key="Network_anal" DataType="NetworkAnalysis">
<local:NetworkAnalysis/>
</DataTemplate>.Resources>
<ListBox.Template>
<ControlTemplate>
<Border Background="Red"/>
</ControlTemplate>
</ListBox.Template>
<ItemsControl ItemsSource="Network_anal"/>
</ListBox>
Am I taking the right approach to this at all?
Here's what I'm trying to do. Below when the "File" button is clicked the side bar displays these 2 expanders:
And when "Network Design" button these expanders are dipslayed:
Option 1:
Subclassing the sections:
each of these sections could be subclassed from a base section class and a specific DataTemplate could be used for each:
<Window x:Class="MiscSamples.MultiToolbar"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:MiscSamples"
Title="MultiToolbar" Height="300" Width="300">
<Window.Resources>
<BooleanToVisibilityConverter x:Key="BoolToVisibilityConverter"/>
</Window.Resources>
<DockPanel>
<ListBox ItemsSource="{Binding Sections}"
SelectedItem="{Binding SelectedSection}"
DisplayMemberPath="Name"
DockPanel.Dock="Top">
<ListBox.ItemContainerStyle>
<Style TargetType="ListBoxItem">
<Setter Property="IsEnabled" Value="{Binding IsEnabled}"/>
<Setter Property="Visibility" Value="{Binding IsVisible, Converter={StaticResource BoolToVisibilityConverter}}"/>
<Setter Property="MinWidth" Value="80"/>
<Setter Property="MinHeight" Value="40"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListBoxItem">
<Border BorderBrush="Black" BorderThickness="1">
<ToggleButton IsChecked="{Binding IsSelected, Mode=TwoWay,RelativeSource={RelativeSource TemplatedParent}}">
<ContentPresenter ContentSource="Content"/>
</ToggleButton>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ListBox.ItemContainerStyle>
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal"/>
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
</ListBox>
<ScrollViewer Width="300" DockPanel.Dock="Left">
<ContentPresenter Content="{Binding SelectedSection}">
<ContentPresenter.Resources>
<DataTemplate DataType="{x:Type local:FileSection}">
<TextBlock Text="User Control For File Section"/>
</DataTemplate>
<DataTemplate DataType="{x:Type local:NetworkDesignSection}">
<TextBlock Text="User Control For Network Design"/>
</DataTemplate>
<DataTemplate DataType="{x:Type local:SelectAnalysisSection}">
<TextBlock Text="User Control For Select Analysis"/>
</DataTemplate>
</ContentPresenter.Resources>
</ContentPresenter>
</ScrollViewer>
<Grid Background="Gray">
<TextBlock Text="Design Surface" TextAlignment="Center" VerticalAlignment="Center" FontWeight="Bold"/>
</Grid>
</DockPanel>
</Window>
Code Behind:
public partial class MultiToolbar : Window
{
public MultiToolbar()
{
InitializeComponent();
var vm = new MainViewModel();
vm.Sections.Add(new FileSection() {Name = "File"});
vm.Sections.Add(new NetworkDesignSection() { Name = "Network Design" });
vm.Sections.Add(new SelectAnalysisSection() { Name = "Select Analysis" });
DataContext = vm;
}
}
Main ViewModel:
public class MainViewModel: PropertyChangedBase
{
private ObservableCollection<Section> _sections;
public ObservableCollection<Section> Sections
{
get { return _sections ?? (_sections = new ObservableCollection<Section>()); }
}
private Section _selectedSection;
public Section SelectedSection
{
get { return _selectedSection; }
set
{
_selectedSection = value;
OnPropertyChanged("SelectedSection");
}
}
}
Sections:
public abstract class Section:PropertyChangedBase
{
public string Name { get; set; }
private bool _isEnabled = true;
public bool IsEnabled
{
get { return _isEnabled; }
set
{
_isEnabled = value;
OnPropertyChanged("IsEnabled");
}
}
private bool _isVisible = true;
public bool IsVisible
{
get { return _isVisible; }
set
{
_isVisible = value;
OnPropertyChanged("IsVisible");
}
}
//Optionally
//public string ImageSource {get;set;}
//ImageSource = "/Resources/MySection.png";
}
public class FileSection: Section
{
///... Custom logic specific to this Section
}
public class NetworkDesignSection:Section
{
///... Custom logic specific to this Section
}
public class SelectAnalysisSection: Section
{
///... Custom logic specific to File Section
}
//...etc etc etc
Result:
Notice that I'm using ToggleButtons bound to the ListBoxItem.IsSelected property to simulate a TabControl-like behavior.
You can set the DataContext of the whole form and bind the ItemsSource of the listbox, or set ItemsSource of the listbox to some collection directly.

Displaying hierarchial structure - missing/invalid datacontext

I'm trying to display this hierarchial structure:
public interface IProgressIndicator
{
CancellationToken CancellationToken { get; }
string Name { get; set; }
}
public interface IPercentageProgressIndicator : IProgressIndicator
{
int ProgressPercentage { get; set; }
}
public interface ICountProgressIndicator : IProgressIndicator
{
int ProgressPercentage { get; }
int CurValue { get; set; }
int MaxValue { get; set; }
}
public interface ICompositeProgressIndicator : ICountProgressIndicator
{
ObservableCollection<IProgressIndicator> SubProgressItems { get; }
void MarkAsComplete(IProgressIndicator progress);
IPercentageProgressIndicator CreatePercentageIndicator();
ICountProgressIndicator CreateCountIndicator();
ICompositeProgressIndicator CreateCompositeIndicator();
}
The view shouldn't assume the hierarchial structure is in place; i.e. a regular IProgressIndicator should be displayed (using ContentControl) and using DataTemplates display other types.
So, when IProgressIndicator is of ICompositeProgressIndicator, then the root of the whole hierarchy should be a TreeView, with root tree view item displaying information (like ProgressPercentage and Name). Then children should be displayed again as IProgressIndicator and using DataTemplates choose appropriate way to view its data. Nested ICompositeProgressIndicator objects should just add another tree view item (not whole TreeView).
Here's what I came up with. I had to use Complex Hierarchical Data Templates. Also I'm using custom DataTemplateSelector, which is fairly simple:
public class ProgressIndicatorTemplateSelector : DataTemplateSelector
{
public override DataTemplate SelectTemplate(object item, DependencyObject container)
{
var element = (container as FrameworkElement);
if (item is ICompositeProgressIndicator)
return element.FindResource("CompositeProgressIndicatorTemplate") as DataTemplate;
else if (item is ICountProgressIndicator)
return element.FindResource("CountProgressIndicatorTemplate") as DataTemplate;
else if (item is IPercentageProgressIndicator)
return element.FindResource("PercentageProgressIndicatorTemplate") as DataTemplate;
return null;
}
}
Here's XAML:
<StackPanel Grid.Row="2" Margin="5" Orientation="Vertical">
<StackPanel.Resources>
<editorUtil:ProgressIndicatorTemplateSelector x:Key="progressIndicatorTemplateSelector" />
<Converters:ObjectToTypeConverter x:Key="objectTypeConverter" />
<DataTemplate x:Key="CompositeProgressIndicatorTemplateBase">
<StackPanel Orientation="Vertical">
<TextBlock Text="CompositeProgressIndicatorTemplateBase" />
<TextBlock Text="{Binding Name}" />
<TextBlock Text="{Binding SubProgressItems.Count}" />
<TextBlock Text="{Binding Converter={StaticResource objectTypeConverter}}" Margin="5" />
</StackPanel>
</DataTemplate>
<DataTemplate x:Key="CompositeProgressIndicatorTemplate">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<StackPanel Grid.Row="0" Orientation="Vertical">
<TextBlock Text="CompositeProgressIndicatorTemplateBase" />
<TextBlock Text="{Binding Name}" />
<TextBlock Text="{Binding SubProgressItems.Count}" />
<TextBlock Text="{Binding Converter={StaticResource objectTypeConverter}}" Margin="5" />
</StackPanel>
<TreeView Grid.Row="1" DataContext="{Binding}">
<TreeView.ItemContainerStyle>
<Style TargetType="{x:Type TreeViewItem}">
<Setter Property="IsExpanded" Value="true"/>
</Style>
</TreeView.ItemContainerStyle>
<TreeViewItem ItemsSource="{Binding SubProgressItems}" DataContext="{Binding}"
ItemTemplateSelector="{StaticResource progressIndicatorTemplateSelector}" IsExpanded="True">
<TreeViewItem.HeaderTemplate>
<DataTemplate>
<StackPanel Orientation="Vertical">
<StackPanel.DataContext>
<Binding RelativeSource="{RelativeSource FindAncestor, AncestorType={x:Type coreUtil:ICompositeProgressIndicator}}"
Path="."/>
</StackPanel.DataContext>
<TextBlock Text="CompositeProgressIndicatorTemplate" />
<ContentControl ContentTemplate="{StaticResource CompositeProgressIndicatorTemplateBase}">
<ContentControl.DataContext>
<Binding RelativeSource="{RelativeSource FindAncestor, AncestorType={x:Type coreUtil:ICompositeProgressIndicator}}"
Path="."/>
</ContentControl.DataContext>
</ContentControl>
</StackPanel>
</DataTemplate>
</TreeViewItem.HeaderTemplate>
</TreeViewItem>
</TreeView>
</Grid>
</DataTemplate>
<HierarchicalDataTemplate DataType="{x:Type coreUtil:ICompositeProgressIndicator}" ItemsSource="{Binding Path=SubProgressItems}">
<ContentControl ContentTemplate="{StaticResource CompositeProgressIndicatorTemplateBase}" />
</HierarchicalDataTemplate>
<DataTemplate x:Key="CountProgressIndicatorTemplate" DataType="{x:Type coreUtil:ICountProgressIndicator}">
<Grid>
<ProgressBar Height="20" Value="{Binding ProgressPercentage, Mode=OneWay}" />
<TextBlock Margin="5" HorizontalAlignment="Center" Text="{Binding ProgressPercentage, Converter={StaticResource percentageConverter}, StringFormat=P}" />
</Grid>
</DataTemplate>
<DataTemplate x:Key="PercentageProgressIndicatorTemplate" DataType="{x:Type coreUtil:IPercentageProgressIndicator}">
<Grid>
<ProgressBar Height="20" Value="{Binding ProgressPercentage, Mode=OneWay}" />
<TextBlock Margin="5" HorizontalAlignment="Center" Text="{Binding ProgressPercentage, Converter={StaticResource percentageConverter}, StringFormat=P}" />
</Grid>
</DataTemplate>
</StackPanel.Resources>
<ContentControl Content="{Binding ProgressIndicator}" ContentTemplateSelector="{StaticResource progressIndicatorTemplateSelector}">
</ContentControl>
</StackPanel>
Here's how it looks at the moment:
There's missing DataContext for the root tree view item.

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