Develop Reference

Retrieve and save the Dynamic added control in WPF Xaml?

I have added the template based on this link
I have an Add button - when I click on it through Command I add it to a collection.
<ItemsControl ItemsSource="{Binding Collection}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Grid DataContext="{StaticResource VieWModel}">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="15*"/>
<ColumnDefinition Width="40*"/>
</Grid.ColumnDefinitions>
<Label Content="GH" Grid.Row="0" Grid.Column="0" VerticalContentAlignment="Center"></Label>
<tk:RadComboBox Grid.Row="0" Grid.Column="0" Margin="10" IsFilteringEnabled="True" Width="150" DisplayMemberPath="D" IsEditable="True" ItemsSource="{Binding GK}" SelectedItem="{Binding SK, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}">
<i:Interaction.Triggers>
<i:EventTrigger EventName="SelectionChanged">
<i:InvokeCommandAction Command="{Binding SelectionChangedCommand}" CommandParameter="{Binding}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</tk:RadComboBox>
<Label Content="HB" Grid.Row="0" Grid.Column="1" VerticalContentAlignment="Center"></Label>
<tk:RadComboBox Grid.Row="0" Grid.Column="1" Margin="10" IsFilteringEnabled="True" Name="cb" Width="350" IsEditable="True" DisplayMemberPath="D" ItemsSource="{Binding VR}" SelectedItem="{Binding VR1,Mode=TwoWay}">
</tk:RadComboBox>
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
ViewModel sample code:
// Property for selected Item in combox1
Public ValBase SK{get;set;}
//Property off combobox1 binding
Public ValBase GK{get;set;}
// Property ofor selected Item in combox2
Public ValBase VR1{get; set;}
//Property ofr combobox2 binding
Public ValBase VR{get;set;}
Public void AddButton(object obj)
{
var item =new collectionbase();
Collection.Add(item)
}
Whenever I click the Add Button this itemplate will be added.
MyRequirement :
When I Click Add Button for the first time ,template should get added
When I click Add Button for the second time Previous generated controls Must have contain the values,only then controls should be added to a collection and then new controls should be created
And I dont know how to save those values dynamically created in a collection
I am running out of Ideas how to achieve this can anyone help . MVVM pattern

I guess you are having Collection in MainViewModel and Command for add Model.
private Model _lastAdded;
public Model LastAdded
{
get{return _lastAdded;}
set{_lastAdded = value;}
}
private void AddCommand(object obj)
{
if(_lastAdded != null && _lastAdded.SelectedValue != null)
{
var newItem = new Model();
Collection.Add(newItem);
_lastAdded = newItem;
}
else
{
//Show message
}
}

Using Selector Class.I have used CurrentInstance To Bind the Collection its working fine now

ListBox in RowDetail binding failure

I have a WPF application. It contains OrderBlock object which contains other objects, plesase see a brief view of the class.
public class OrderBlocks
{
private List<Order> _orders;
[XmlElement("tF_Transactions")]
public List<Order> Orders { get { return _orders; } set { _orders = value; OnPropertyChanged("Orders"); } }
}
public class Order : INotifyPropertyChanged
{
[XmlIgnore]
public List<Duplications> DuplicateHolder { get; set; }
}
public class Duplications
{
public string ID { get; set; }
public string Name { get; set; }
public Duplications(string newID, string newName)
{
ID = newID;
Name = newName;
}
}
I have a datagrid that is bound to my object Orders of type List Orders. My datagrid has a row detail so that when a user clicks on a row further details are displayed. I have added a listbox to this row detail. I want this row detail to show a listbox which displays my object DuplicateHolder of type List Duplications.
At the moment the listbox is empty. Please see my attempted XAML code below. Any help would be great as always.
<ListBox Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="3" Name="lbIdentifier" SelectionMode="Single" DataContext="{Binding OrderBlock}" HorizontalContentAlignment="Stretch">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid Margin="0,2">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<TextBlock Grid.Column="0" Text="{Binding Path=DuplicateHolder.ID}" FontSize="10" HorizontalAlignment="Left" Margin="5,0,0,0"/>
<TextBlock Grid.Column="1" Text="{Binding Path=DuplicateHolder.Name}" FontSize="10" HorizontalAlignment="Left" Margin="5,0,0,0"/>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>

Try this
<Listbox ItemSource = {Binding DuplicateHolder}/>
and
<TextBlock Grid.Column="0" Text="{Binding Path=ID}".../>

t seems like you did not set the bindings correctly because the listbox Context should be a list of Duplications and the ItemTemplate should be for one Duplication instance from the list of duplicates. So if the global datacontext is an instance of OrderBlocks the listbox will be bound to the DuplicateHolder of an Order:
<ListBox Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="3" Name="lbIdentifier" SelectionMode="Single" DataContext="{Binding Path=DuplicateHolder}" HorizontalContentAlignment="Stretch">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid Margin="0,2">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<TextBlock Grid.Column="0" Text="{Binding Path=ID}" FontSize="10" HorizontalAlignment="Left" Margin="5,0,0,0"/>
<TextBlock Grid.Column="1" Text="{Binding Path=Name}" FontSize="10" HorizontalAlignment="Left" Margin="5,0,0,0"/>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>

How to have recursion, or a hierarchy lists and sublists in XAML?

Say I have the following class, Employee
public class Employee
{
public int Id { get; set; }
public string Name { get; set; }
public ObservableCollection<Employee> Underlings { get; set; }
}
And then I have the following XAML, bound to an ObservableCollection<Employee> MyEmployees
<ListBox ItemsSource="{Binding Path=MyEmployees}">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid Tag="{Binding Path=Employee.Id}">
<TextBlock Text="{Binding Path=Employee.Name}"></TextBlock>
<!-- Here's where I declare my underlings -->
<ListBox ItemsSource="{Binding Path=Employee.Underlings}">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid Tag="{Binding Path=Employee.Id}">
<TextBlock Text="{Binding Path=Employee.Name}"></TextBlock>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
This allows each employee in the collection MyEmployees to have some underlings. But those underlings are also of type employee, and could have their own underlings. How do I cater for those additional levels without making my XAML very complex?
Is there some way to declare my DataTemplate separately and allow it to be referenced within itself?
Do I have to do all this from code-behind instead?
(I realise the XAML above may not be 100% correct, its just an example)

therefore you have to use a TreeView and not a ListBox. And You have to specify a HierarchicalDataTemplate.

You could define the DataTemplate inside the ListBoxes Resources as the default template for Employees:
<ListBox ItemsSource="{Binding MyEmployees}">
<ListBox.Resources>
<DataTemplate DataType="{x:Type myns:Employee}">
<Grid Tag="{Binding Id}">
<TextBlock Text="{Binding Name}"></TextBlock>
<ListBox ItemsSource="{Binding Underlings}" />
</Grid>
</DataTemplate>
</ListBox.Resources>
</ListBox>

Set combobox display text to a property of ObservableCollection<T>

I have the following collection which i would like to bind to a combobox:
public ObservableCollection<Parameter> Values
{ get; set; }
public class Parameter
{
public String Text { get; set; }
public String Value { get; set; }
}
I need to bind the display text of the combobox to the Text property of the Parameter class, I've tried the following ways below but all to no avail:
<ComboBox ItemsSource="{Binding Values}" DisplayMemberPath="Parameter.Text"
<ComboBox ItemsSource="{Binding Values}" DisplayMemberPath="Parameter\Text"
<ComboBox ItemsSource="{Binding Values}" DisplayMemberPath="Text"
When I try the 3 methods above the [assembly name].Parameter is displayed in the combobox for each parameter.
The 2 methods above don't display anything in the combobox
<ComboBox ItemsSource="{Binding Values, Path=Text}"
<ComboBox ItemsSource="{Binding Values, Path=Values.Text}"
And this one takes the text of the first parameter,splits it into characters and displays each character as a seperate item in the combobox:
<ComboBox ItemsSource="{Binding Values, Path=Values/Text}"
UPDATE:
This is the complete XAML code as requested
<ListBox BorderBrush="{x:Null}" Grid.Column="0" Height="100" Grid.ColumnSpan="2" Grid.Row="1" ItemsSource="{Binding ItemParams}" ScrollViewer.VerticalScrollBarVisibility="Auto" Margin="2" HorizontalContentAlignment="Stretch">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="100" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<TextBlock TextTrimming="CharacterEllipsis" Grid.Column="0" Margin="2" Text="{Binding Name}" Background="{Binding ElementName=cmbColors, Path=SelectedItem}"/>
<ComboBox ItemsSource="{Binding Values}" DisplayMemberPath="Text" SelectedIndex="0" HorizontalAlignment="Left" Grid.Column="1" Margin="2" Width="150" Name="cmbColors" >
<ComboBox.ItemTemplate>
<DataTemplate>
<TextBlock Grid.Column="1" Margin="2, 1" Text="{Binding}"/>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Params class:
public class Params
{
public Params(String name, ObservableCollection<Parameter> values)
{
Name = name;
Values = values;
}
public String Name
{ get; set; }
public ObservableCollection<Parameter> Values
{ get; set; }
}

The correct formulation is one of those you already mention:
<ComboBox ItemsSource="{Binding Values}" DisplayMemberPath="Text"
Please check again, and if it does not work post the XAML that you have verbatim.

You can do directly :
<ComboBox ItemsSource="{Binding Values}" DisplayMemberPath="Text" />
For WPF every element of the ComboBox (ComboBoxItem) is a of type T, thus it will look for public properties on the T, this why just putting Text will work.

Had to simply remove the combobox item template or set Text="{Binding Text}"
<ComboBox.ItemTemplate>
<DataTemplate>
<TextBlock Grid.Column="1" Margin="2, 1" Text="{Binding}"/>
</DataTemplate>
</ComboBox.ItemTemplate>

Changing the data for a ComboBox in WPF

So I have a ComboBox with data in it and it works how they want:
<ComboBox Grid.Column="1" x:Name="MyComboBox" Margin="2, 0, 2, 0"
ItemsSource="{Binding Path=MySamples}" DisplayMemberPath="SampleName" SelectedValue="{Binding Path=MySample}"
SelectionChanged="OnComboBoxChanged" FontSize="11" FontFamily="Arial"/>
However, now they want the ItemsSource to be indexed. So it should be something like:
some #: SampleName
Is there an easy way to make this change just for the ComboBox drop down without changing the architecture? I cannot change the List itself since in other areas of the map, it's just the SampleName without the index. Thanks.

If your ItemsSource is a complex type:
public class MyClass
{
public int Index { get; set; }
public string Name { get; set; }
}
Then use the DisplayMemberPath property of the ComboBox to control what gets displayed. In this case you'd add:
DisplayMemberPath="SampleName"
to the ComboBox definition.
If instead you want to display both the index and name then you'll need to define an ItemTemplate for the ComboBox:
<ComboBox ....>
<ComboBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Index}" />
<TextBlock Text=" : " />
<TextBlock Text="{Binding Name}" />
</StackPanel>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>