How to get a parent value in multibinding - c#

I'm using dataTemplate. This is the template:
<ItemsControl ItemsSource="{Binding RAM.Partitions}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Grid>
<TextBlock Text="{Binding Position, StringFormat={}{0}k}"/>
<Grid Grid.Column="1">
<Border>
<Border.Height>
<MultiBinding Converter="{StaticResource MultiplyConverter}">
<Binding ElementName="LayoutRoot" Path="ActualHeight"/>
<Binding Path="Size" />
<Binding Path="RAM.Size" />
</MultiBinding>
</Border.Height>
</Border>
</Grid>
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
Can you see this line?
<Binding Path="RAM.Size" />
That line throws me an exception, it should be because RAM.Size is from a parent element. How might I get that value?
Thanks in advance!

So you're trying to get to the RAM.Size value on the same object that your ItemsControl is getting its ItemsSource from?
See if this works:
<MultiBinding Converter="{StaticResource MultiplyConverter}">
<Binding ElementName="LayoutRoot" Path="ActualHeight"/>
<Binding Path="Size" />
<Binding Path="DataContext.RAM.Size"
RelativeSource="{RelativeSource Mode=FindAncestor,AncestorType=ItemsControl}" />
</MultiBinding>
So the binding is going up in through the visual tree to the ItemsControl, then binding to the Ram.Size property of its DataContext.

Related

WPF Binding in textblock does not work but in its tooltip does

I have a weird issue.
In my application (witten with C# .net framework 4.8 with Microsoft's MVVM toolkit) I have a ListView bound to a BindingList<VisualMachine>, everything works as expected.
Now I wanted to add to the Itemtemplate a DockPanel with data from another BindingList<PreviewParameter> (another property of the original VisualMachine object ).
This is when weirdness starts: In this new ItemTemplate I have a Grid that contains an Image, a TextBlock and a Tooltip. The TextBlock and the Tooltip are bound to the same object, but only the ToolTip actually show data!
I feel like it's some DataContext Issue, but I am not able to pin it... Can anybody give me some advice?
Thanks!
The code:
<ListView Name="MachinesListView" Margin="2" HorizontalContentAlignment="Stretch" BorderThickness="0" DockPanel.Dock="Top" ItemsSource="{Binding Path=Machines}" PreviewMouseRightButtonDown="ListView_PreviewMouseRightButtonDown" SelectedItem="{Binding Path=SelectedMachine}">
<ListView.ItemTemplate>
<DataTemplate>
<!-- Other stuff -->
<DockPanel>
<!--#region PREVIEW PARAMETERS PANEL-->
<WrapPanel HorizontalAlignment="Stretch" DockPanel.Dock="Bottom" Visibility="{Binding Path=PreviewParameters.Count, Converter={StaticResource CountToVisConverter}}">
<ListView ItemsSource="{Binding Path=PreviewParameters}">
<ListView.ItemTemplate>
<DataTemplate>
<Grid MinWidth="50">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="25"/>
<ColumnDefinition Width="Auto" MinWidth="25"/>
</Grid.ColumnDefinitions>
<Image Grid.Column="0" Source="{Binding Path=Icon, Converter={StaticResource ResourceKey=BmpToBmpImageConverter}}"/>
<TextBlock Grid.Column="1" MaxWidth="100" DataContext="{Binding}">
<TextBlock.Text>
<!-- THIS DOES NOT APPEAR -->
<MultiBinding StringFormat="{}{0} [{1}]}">
<Binding Path="Parameter.VisualizedValue"/>
<Binding Converter="{StaticResource ParamToEnumDescConverter}" Path="Parameter"/>
</MultiBinding>
</TextBlock.Text>
</TextBlock>
<Grid.ToolTip>
<TextBlock MaxWidth="100" TextWrapping="Wrap">
<TextBlock.Text>
<!-- THIS DOES APPEAR -->
<MultiBinding StringFormat="{}{0} [{1}] - {2} TEST:{3} {4}">
<Binding Path="Parameter.Reference"/>
<Binding Path="Parameter.SetupIndex"/>
<Binding Path="Description"/>
<Binding Path="Parameter.VisualizedValue"/>
<Binding Converter="{StaticResource ParamToEnumDescConverter}" Path="Parameter"/>
</MultiBinding>
</TextBlock.Text>
</TextBlock>
</Grid.ToolTip>
</Grid>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</WrapPanel>
<!-- Other stuff -->
</DockPanel>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
What happens:
I found it.
There was a } in the StringFormat property of the TextBlock's MultiBinding.
So instead of
<MultiBinding StringFormat="{}{0} [{1}]}">
it should be
<MultiBinding StringFormat="{}{0} [{1}]">
And BAM! Now it works.
I'll leave the question as the following reminder to anybody: "Write your code, review it, than go take a coffee o chat a little and then come back. You'll be amazed on how blind you could be."

WPF object binding from parent itemscontrol

I have Groups collection property in my viewmodel and each group has its Teams collection.
I want to remove a team from group with a button click. How can I bind the group in which the team is to the command parameter? This solution is not working:
<ItemsControl ItemsSource="{Binding Groups}" Name="gSource" Tag="{Binding .}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel Orientation="Horizontal"/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<ItemsControl ItemsSource="{Binding Teams}" Name="tSource">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Vertical"/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<Button Command="{Binding Path=DataContext.RemoveTeamFromGroupCommand, ElementName=gSource}">
<Button.CommandParameter>
<MultiBinding Converter="{StaticResource ObjectsConverter}">
<Binding Path="."/>
<Binding Path="Tag.Value" RelativeSource="{RelativeSource AncestorType=ItemsControl}"/>
</MultiBinding>
</Button.CommandParameter>
</Button>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
It binds the team properly, but instead of group it binds MS.Internal.NamedObject with unset value.
#Tam Bui is perfectly right about using the DataContext of the parent ItemsControl.
But besides "RelativeSource AncestorType", you can name the UI elements inside the DataTemplate (you assigned the tSource) and use them.
You used a similar binding to bind the command.
Also, Binding by default provides a link to the current data context.
It is not necessary to give it Path.
Alternative solution:
<Button Command="{Binding Path=DataContext.RemoveTeamFromGroupCommand, ElementName=gSource}">
<Button.CommandParameter>
<MultiBinding Converter="{StaticResource ObjectsConverter}">
<Binding/>
<Binding Path="DataContext" ElementName="tSource"/>
</MultiBinding>
</Button.CommandParameter>
</Button>
The Tag is unnecessary if you want the Group to be the 2nd binding of your MultiBinding. Instead, just bind it to the DataContext of the relative ancestor ItemsControl. I tested this and it worked.
<MultiBinding Converter="{StaticResource ObjectsConverter}">
<Binding Path="."/>
<Binding Path="DataContext" RelativeSource="{RelativeSource AncestorType=ItemsControl}"/>
</MultiBinding>

WPF - ToolTip with multibinding

I want to make a tooltip with multibinding inside a text block, but whatever I try it doesn't work.
Here is what I've tried so far:
<TextBlock Text="{Binding Description, StringFormat='Description : {0}{}'}">
<ToolTipService.ToolTip>
<TextBlock>
<TextBlock.Text>
<MultiBinding StringFormat="Description : {0}{1}{}">
<Binding Path="FirstDescription" />
<Binding Path="SecondDescription" />
</MultiBinding>
</TextBlock.Text>
</TextBlock>
</ToolTipService.ToolTip>
</TextBlock>
But when I try it, what I see on the tooltip is : System.Windows.Controls.TextBlock.
when i try it without tooltipservice, and only tooltip, like this :
<TextBlock Text="{Binding Description, StringFormat='Description : {0}{}'}">
<ToolTip>
<TextBlock>
<TextBlock.Text>
<MultiBinding StringFormat="Description : {0}{1}{}">
<Binding Path="FirstDescription" />
<Binding Path="SecondDescription" />
</MultiBinding>
</TextBlock.Text>
</TextBlock>
</ToolTip>
</TextBlock>
The screen just get stuck.
I dont't know wich VS version you are using but:
<TextBlock Text="{Binding Description, StringFormat="Description : {0}{}"}">
does not even compile for me.
Just remove the " and the empty brackets like that:
<TextBlock Text="{Binding Description, StringFormat=Description : {0}">
You could also write it like this if you want the ":
<TextBlock>
<TextBlock.Text>
<Binding Path="Description" StringFormat="Description : {0}" />
</TextBlock.Text>
<ToolTipService.ToolTip>
<TextBlock>
<TextBlock.Text>
<MultiBinding StringFormat="Description : {0}{1}">
<Binding Path="FirstDescription" />
<Binding Path="SecondDescription" />
</MultiBinding>
</TextBlock.Text>
</TextBlock>
</ToolTipService.ToolTip>
</TextBlock>
I have tried the following code and that worked perfectly:
<TextBlock Margin="20" Foreground="Black" FontSize="20" FontFamily="Century Gothic" Text="{Binding Name1}">
<TextBlock.ToolTip>
<TextBlock>
<TextBlock.Text>
<MultiBinding StringFormat="MultiBinded Tooltip : {0}{1}">
<Binding Path="Name1"/>
<Binding Path="Name2"/>
</MultiBinding>
</TextBlock.Text>
</TextBlock>
</TextBlock.ToolTip>
</TextBlock>
Just delete empty brackets. Next code work as expected:
<TextBlock Text="{Binding Description, StringFormat='Description : {0}'}">
<ToolTipService.ToolTip>
<TextBlock>
<TextBlock.Text>
<MultiBinding StringFormat="Description : {0}{1}">
<Binding Path="FirstDescription" />
<Binding Path="SecondDescription" />
</MultiBinding>
</TextBlock.Text>
</TextBlock>
</ToolTipService.ToolTip>
</TextBlock>
If the StringFormat starts with a left brace { the XAML parser require you to escape it using a pair of braces {}. Otherwise the parser gets confused because braces also are used in the syntax of markup extensions.
Details are found in the XAML documentation for {} Escape Sequence / Markup Extension.
Also, you can't use double quotes with inline binding but single quotes is available.

Generically replace Converter in MultiBinding node

I have some RadioButton’s that I want to change the Visibility of based on multiple properties in the ViewModel. Each RadioButton’s Visibility will vary based on the same list of properties. I have the following xaml:
<RadioButton Command="{Binding Path=SomeCommand}"
CommandParameter="SomeCommandParameter"
Content="RB 1">
<RadioButton.Visibility>
<MultiBinding Converter="{StaticResource Rb1Visibility}">
<Binding Path="Value1"
RelativeSource="{RelativeSource Self}" />
<Binding Path="Value2"
RelativeSource="{RelativeSource Self}" />
</MultiBinding>
</RadioButton.Visibility>
</RadioButton>
I would like to change the Converter for each RadioButton option, but everything else would remain the same (all the Bindings). I don’t want to duplicate all the xaml code for this. I originally tried creating a style for the RadioButton, but I could not figure out how to pass the Converter to the Style resource:
<Style x:Key="RbVisibilityStyle"
TargetType="{x:Type RadioButton}">
<Setter Property="Visibility">
<Setter.Value>
<MultiBinding Converter="{???? Pass in converter ?????}">
<Binding Path="Value1"
RelativeSource="{RelativeSource Self}" />
<Binding Path="Value2"
RelativeSource="{RelativeSource Self}" />
</MultiBinding>
</Setter.Value>
</Setter>
</Style>
I could create a “Visibility” property for each RadioButton in the ViewModel, but that adds a lot of code to the ViewModel and addition PropertyChanged event handling.
Is there an easy way to generically bubble up the MultiBinding so I don’t duplicate the code throughout the entire xaml file? Is there a different approach I should be taking?
Update - Adding a more complex example
<RadioButton Command="{Binding Path=SomeCommand}"
CommandParameter="SomeCommandParameter"
Content="RB 1">
<RadioButton.Visibility>
<MultiBinding Converter="{StaticResource Rb1Visibility}">
<Binding Path="Value1"
RelativeSource="{RelativeSource Self}" />
<Binding Path="Value2"
RelativeSource="{RelativeSource Self}" />
</MultiBinding>
</RadioButton.Visibility>
</RadioButton>
<RadioButton Command="{Binding Path=SomeCommand2}"
CommandParameter="SomeCommandParameter2"
Content="RB 2">
<RadioButton.Visibility>
<MultiBinding Converter="{StaticResource Rb2Visibility}">
<Binding Path="Value1"
RelativeSource="{RelativeSource Self}" />
<Binding Path="Value2"
RelativeSource="{RelativeSource Self}" />
</MultiBinding>
</RadioButton.Visibility>
</RadioButton>
<RadioButton Command="{Binding Path=SomeCommand3}"
CommandParameter="SomeCommandParameter3"
Content="RB 3">
<RadioButton.Visibility>
<MultiBinding Converter="{StaticResource Rb3Visibility}">
<Binding Path="Value1"
RelativeSource="{RelativeSource Self}" />
<Binding Path="Value2"
RelativeSource="{RelativeSource Self}" />
</MultiBinding>
</RadioButton.Visibility>
</RadioButton>
How do I reduce the MultiBinding redundancy here?
would like to change the Converter for each RadioButton option,
Create a new MultiValueConverter which takes an extra parameter (the radio button option) and then simply route the call to the appropriate converter based on that option.
One can put the option in the Tag property on the control's Xaml.
Example
Its not clear to me what that option you mention is, so in my example let us uniquely identify each Radio Button by its Tag property and use the routing converter to find the appropriate converter based off of the Tag supplied.
<RadioButton Tag="1"/><RadioButton Tag="2"/>
Then change the style to use the new converter with the new parameter:
<Style x:Key="RbVisibilityStyle"
TargetType="{x:Type RadioButton}">
<Setter Property="Visibility">
<Setter.Value>
<MultiBinding Converter="{StaticResource RouterViaTagVisibilityConverter">
<Binding Path="Value1"
RelativeSource="{RelativeSource Self}" />
<Binding Path="Value2"
RelativeSource="{RelativeSource Self}" />
<Binding Path="Tag"
RelativeSource="{RelativeSource Self}" />
</MultiBinding>
</Setter.Value>
</Setter>
</Style>

WPF Multibinding .Net Framework 4.0

I have the following DataGridTemplate column:
<DataGridTemplateColumn x:Name="specialtiesColumn" Header="Specialties" MinWidth="170">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<ComboBox ItemsSource="{Binding Path=DataContext.Specialties, Mode=OneWay, RelativeSource={RelativeSource FindAncestor, AncestorType=DataGrid}}">
<ComboBox.ItemTemplate>
<DataTemplate>
<StackPanel Height="17" VerticalAlignment="Center" Orientation="Horizontal">
<CheckBox Width="20">
<CheckBox.IsChecked>
<MultiBinding Converter="{StaticResource ProviderSpecialtyIsInSpecialtiesConverter}">
<Binding RelativeSource="{RelativeSource FindAncestor, AncestorType=ComboBox}" Path="DataContext.Specialties" />
<Binding Path="Name" />
</MultiBinding>
</CheckBox.IsChecked>
</CheckBox>
<TextBlock Text="{Binding Name}" Width="130" />
</StackPanel>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
What I am trying to do is have a column of comboboxes inside a datagrid, and each combobox have several checkboxes. Each row of the datagrid represent hospitals. The combobox will show which specialties the hospital has, and the user should also be able to modify these selections.
This is the code for the converter:
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
try
{
HashSet<Specialty> specialties = (HashSet<Specialty>)values[0];
string specialty = (string)values[1];
foreach (Specialty s in specialties)
{
if (s.Name == specialty)
return true;
}
return false;
}
catch (Exception)
{
return false;
}
}
This works on computers with .Net Framework 4.5, but it crashes when trying to load with only .Net Framework 4.0. The project is targeted for .Net Framework 4.0.
I suppose the reason for that is that the MultiBinding is using the RelativeSource and the DataGridColumn is not a part of visual tree. They must have fixed the column binding behaviour in 4.5. I got the same issue woth my code that looked like this:
<DataGridTextColumn.Binding>
<MultiBinding Converter="{StaticResource directionConverter}">
<MultiBinding.Bindings>
<Binding ElementName="clientPerspective" Path="IsChecked"/>
<Binding Path="Direction"/>
</MultiBinding.Bindings>
</MultiBinding>
</DataGridTextColumn.Binding>`

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