DependencyProperty Binding Does Not Update To Collection CurrentItem - c#

I am trying to bind a dependency property to a collection's current selection and for reasons I can't seem to grasp, the binding does not update when the collection changes.
In the example below, I show two example. One is updating correctly (on the textblock/run), and the other only displays the initial element and doesn't change when the data grid selection changes.
<Grid>
<Grid.Resources>
<CollectionViewSource Source="{Binding Path=List}" x:Key="myViewModel"/>
<my:UpdateNotWorking MyObjModel="{Binding Source={StaticResource myViewModel}, Path=CurrentItem}" x:Key="updateNotWorking" />
</Grid.Resources>
<DataGrid ItemsSource="{Binding Source={StaticResource myViewModel}}" Name="mylistbox"/>
<TextBlock TextWrapping="Wrap" FontWeight="Bold" Foreground="#FF50CEFF" FontSize="24" TextAlignment="Center" Height="75">
<Run Text="{Binding Source={StaticResource myViewModel}, Path=text}" Foreground="#FF00E200" />
</TextBlock>
<TextBox Text="{Binding Source={StaticResource updateNotWorking}, Path=MyObjModel.text}" Height="22"/>
</Grid>
My dependency property in this example is "MyObjModel" on the "UpdateNotWorking" dependency object which is instantiated from the xaml code.
I would appreciate any information as to why my property is not updating correctly.
Example Project

Paste this XAML into your MainWindow.
<Grid>
<Grid.Resources>
<CollectionViewSource Source="{Binding Path=List}" x:Key="myViewModel" />
<my:UpdateNotWorking x:Key="updateNotWorking" />
</Grid.Resources>
<DataGrid ItemsSource="{Binding Source={StaticResource myViewModel}}" Name="mylistbox"
SelectedItem="{Binding Source={StaticResource updateNotWorking}, Path=MyObjModel, UpdateSourceTrigger=PropertyChanged}" />
<TextBlock TextWrapping="Wrap" FontWeight="Bold" Foreground="#FF50CEFF" FontSize="24" TextAlignment="Center"
Height="75">
<Run Text="{Binding Source={StaticResource myViewModel}, Path=text}" Foreground="#FF00E200" />
</TextBlock>
<TextBox Text="{Binding Source={StaticResource updateNotWorking}, Path=MyObjModel.text, UpdateSourceTrigger=PropertyChanged}"
Height="22" />
</Grid>
What it is now doing is setting updateNotWorking's MyObjModel property based on the DataGrid's SelectedValue, with UpdatePropertyTrigger set to PropertyChanged to see the changes immediately. No longer do we need to define updateNotWorking's property through the List's CurrentItem because it is not going to change just by selecting it with a DataGrid. You can keep it set, but it is not required as we are doing all the manual labor with the DataGrid SelectedValue.

Related

WPF Binding TextBlock value to display SelectedItem in ComboBox

I have a ComboBox and a couple of TextBlock fields.
I want to display the properties of a SelectedItem from the ComboBox on those Textblock's. Image
So that when I choose one of multiple user's the properties in the TextBlock will update to those of the SelectedItem. I have found an example, although it is using silverlight, and does not work entirely.
<ComboBox Grid.Row="0"
Grid.Column="0"
VerticalAlignment="Bottom"
VerticalContentAlignment="Center"
HorizontalContentAlignment="Left"
Margin="0"
Height="40"
Name="ComboBox"
ItemsSource="{Binding UserModels}"
SelectedItem="{Binding EnteredUserModel, Mode=TwoWay}">
<ComboBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding FirstName}"
Style="{StaticResource ResourceKey=ComboBoxItemTextBlock}"/>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
</Grid>
<TextBlock Grid.Row="1"
Grid.Column="0"
Margin="0 10 0 10" >
<Run Text="{DynamicResource firstName}" />
<Run Text=": " />
<Run Text="{Binding ElementName=ComboBox, Path=SelectedItem, UpdateSourceTrigger=PropertyChanged}" />
</TextBlock>
This is what I've tried. I added Name to the ComboBox so that I can access it's SelectedItem in my TextBlock. I need to get the SelectedItem.firstname, etc. At this stage i can only access the entire objects.
Am I missing some useful binding?
In order to show the FirstName property of the SelectedItem, just use an appropriate property path, i.e. SelectedItem.FirstName:
<Run Text="{Binding ElementName=ComboBox, Path=SelectedItem.FirstName}" />
or, since SelectedItem is bound to an EnteredUserModel property in your view model:
<Run Text="{Binding Path=EnteredUserModel.FirstName}" />
Setting UpdateSourceTrigger=PropertyChanged is not necessary. It has no effect in a OneWay Binding.
You're getting the EnteredUserModel-Object, because that's the selected item of the ComboBox. If you want the displayed text you must bind to the FirstName-Property.
Alternatively you can bind to EnteredUserModel.FirstName in your TextBox

Visibility binding to ListboxItems inside template

I'm trying to change the Visibility of elements inside a ListBoxItem by clicking on a CheckBox outside the ListBox which contains Items, but it doesn't seem to work.
It looks like the the binding doesn't work inside the ListBoxItems.
I'm using a template for my items
XAML
<UserControl.Resources>
<local:BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter"/>
<DataTemplate x:Key="ShotTemplate">
<Grid x:Name="GridItem" Width="200">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<TextBox x:Name="ShotBox" Grid.Column="1" Text="{Binding Path=Description}" Visibility="{Binding EditMode, ElementName=EditMode, Converter={StaticResource BooleanToVisibilityConverter}}" />
<TextBlock x:Name="ShotBlock" Grid.Column="1" Text="{Binding Path=Description}" Visibility="{Binding EditMode, Converter={StaticResource BooleanToVisibilityConverter}, ConverterParameter=False }" />
</Grid>
</DataTemplate>
</UserControl.Resources>
<Grid>
<ListBox Name="ShotList" ItemsSource="{Binding AllShotsCollection}" ItemTemplate="{StaticResource ShotTemplate}"/>
<CheckBox Name="EditMode" IsChecked="{Binding EditMode}" Content="Edit Mode" HorizontalAlignment="Left" Margin="12,30,0,0" VerticalAlignment="Top"/>
</Grid>
ViewModel
private bool _editMode = true;
public bool EditMode
{
get { return _editMode; }
set { _editMode = value; RaisePropertyChanged("EditMode"); }
}
How do I change ShotBox and ShotBlock Visibility by checking or unchecking the CheckBox. I know the converter works correctly, that's not the problem it must have something to do with the binding.
The ElementName binding scope is within the template only. I would define an attached property on the ListView (not the ListViewItem) and have the Checkbox toggle that property. Within the DataTemplate, you'll be able to use RelativeSource / FindAncestor binding to find the ListView.
This line of xaml code is not working. You are trying to bind to the view element and viewmodel prop. at the same time.
<TextBox x:Name="ShotBox" Grid.Column="1" Text="{Binding Path=Description}" Visibility="{Binding EditMode, ElementName=EditMode, Converter={StaticResource BooleanToVisibilityConverter}}" />
Remove this 'ElementName=EditMode' so that it would bind properly to the viewmodel property 'EditMode'.
OR if you want to bind to the view element only use
Visibility="{Binding Path=IsChecked, ElementName=EditMode, Converter={StaticResource BooleanToVisibilityConverter}}" />

How to bind properties of one ObservableCollection of ListView to properties of SelectedItem of another ListView?

So I have a few ListViews. The first is binded to ObservaleCollection<ComPort>. All properties of ComPort may take some predefined values. Other ListViews are responsible for that properties: they show all that possible (predefined) values and SelectedItem should be the current value of that property of ComPort from the first ObservaleCollection.
I can't attach images so here is an external picture, it would make the situation clean: http://i.stack.imgur.com/ZBRRx.png
<Window.Resources>
<ResourceDictionary x:Name="rd">
<l:ComPorts x:Key="vComPorts"/>
<l:SystemPorts x:Key="vSystemPorts"/>
<l:BaudRates x:Key="vBaudRate"/>
<l:Parities x:Key="vParities"/>
<l:DataBits x:Key="vDataBits"/>
<l:StopBits x:Key="vStopBits"/>
<l:Timeouts x:Key="vTimeouts"/>
<l:ComPort x:Key="vSelectedPort"/>
</ResourceDictionary>
</Window.Resources>
...
<ListView
Name="PortsList"
Grid.Row="1"
Grid.Column="0"
Margin="5"
VerticalAlignment="Stretch"
ItemsSource="{StaticResource vComPorts}"
DataContext="{StaticResource vComPorts}"
SelectedValuePath="PortName"
SelectedValue="{Binding ElementName=SystemPortsList, Path=SelectedItem.Value}"
SelectionChanged="PortsList_SelectionChanged"
MouseDoubleClick="PortsList_MouseDoubleClick">
<ListView.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<CheckBox />
<TextBlock Margin="5,0,0,0" Text="{Binding Path=Name}" />
</StackPanel>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
<ListView
x:Name="SystemPortsList"
Margin="5"
VerticalAlignment="Stretch"
DataContext="{Binding Source={StaticResource vSelectedPort}}"
ItemsSource="{Binding Source={StaticResource vSystemPortsView}}"
SelectedItem="{Binding Source={StaticResource vSelectedPort}, Path=PortName}"
MouseEnter="SystemPortsList_Refresh"
MouseLeave="SystemPortsList_Refresh"
Grid.Row="1"
Grid.Column="1" SelectionChanged="SystemPortsList_SelectionChanged">
<ListView.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Name="tb" Margin="5,0,0,0" Text="{Binding Path=Name}" />
</StackPanel>
</ListView.ItemTemplate>
</ListView>
I've tried to make an instance of class ComPort for saving current value of selected item from the first ListView, but anyway I can't cope with it without help. How this task should be solved?
1) Instead of handling SelectionChanged on the PortsList ListView, bind your checkbox to the ListViewItemsPanel like so:
<CheckBox IsChecked={Binding IsSelected, RelativeSource=Parent/>
2) Add an x:Name to your first ListBox, say x:Name="ComPortLB";
3) Remove DataContext on SystemPortsList;
4) Fix SelectedItem on SystemPortsList like so:
SelectedValue="{Binding ElementName=ComPortLB, Path=SelectedValue.PortName}"
I haven't tested any of this code and I haven't done this kind of stuff for a while, so I apologize for errors, but it should get you closer. I've also had to make some assumptions about your classes since you don't provide enough information.

TextBoxes not synchronized after introducing CollectionViewSource

I'm having trouble with some TextBoxes which are to be synchronized with the current element selected in a ListBox. E.g. I have the following TextBoxes:
<TextBox Style="{StaticResource IdTextboxStyle}" Grid.Row="2" Grid.Column="1" Text="{Binding Path=ID, UpdateSourceTrigger=PropertyChanged}" />
<TextBox Style="{StaticResource TextboxStyle}" Grid.Row="3" Grid.Column="1" Text="{Binding Path=CodeName, UpdateSourceTrigger=PropertyChanged}" />
I also have the following ListBox:
<ListBox Name="ListOfAgentsBox" Margin="20, 5, 5, 5" Grid.Row="2" Grid.Column="2" Grid.RowSpan="4"
IsSynchronizedWithCurrentItem="True" ItemsSource="{Binding Source={StaticResource AgentsViewSource}}"
SelectedIndex="{Binding Path=CurrentIndex, UpdateSourceTrigger=PropertyChanged}">
Which contains the current elements in a collection named Agents, which is a collection of Agent elements.
My problem is, before introducing the following CollectionViewSource:
<CollectionViewSource x:Key="AgentsViewSource"
Source="{StaticResource Agents}">
<CollectionViewSource.SortDescriptions>
<componentModel:SortDescription PropertyName="ID" />
</CollectionViewSource.SortDescriptions>
</CollectionViewSource>
Everything seemed to work fine - I could click the different elements in the ListBox and edit them just fine in the TextBoxes. However, the TextBoxes and the ListBox are no longer syncrhonized, and I have no idea why.

WPF - Select ComboBox value by typing when using DataTemplate

I have a combobox in wpf which is binded to some property (another object). Because I need to show two properties of that object i used DataTemplate inside combobox. Now when combobox is in focus I can't select some value by typing few starting letters (without DataTemplate it is possible).
<ComboBox Height="23" HorizontalAlignment="Left" Margin="104,14,0,0" Name="tipDokumentaCombo" VerticalAlignment="Top" Width="241" TabIndex="0" ItemsSource="{Binding Path=TipoviDokumenta}" SelectedValue="{Binding Path=Potvrda.Tip}" SelectedValuePath="Tip" SelectionChanged="tipDokumentaCombo_SelectionChanged">
<ComboBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=Tip}" />
<TextBlock Text=" (" />
<TextBlock Text="{Binding Path=OpisDokumenta}" />
<TextBlock Text=")" />
</StackPanel>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
Set TextSearch.TextPath to the property that should be searched.
Update
Because the abvove solution seems not to work for you, try to set the search text manually for the container:
<ComboBox.ItemContainerStyle>
<Style TargetType="{x:Type ComboBoxItem}">
<Setter Property="TextSearch.Text" Value="{Binding Tip}" />
</Style>
</ComboBox.ItemContainerStyle>
Add DisplayMemberPath to the property on which lookup should work on.
Setting DisplayMemberPath worked for me even when itemtemplate is present.
Based on the comment discussion, the solution that works is to add both IsTextSearchEnabled="True" and TextSearch.TextPath="Tip" in the ComboBox tag.
For example (re-writting the question code sample - removing some not useful to the example code to reduce complexity)
<ComboBox Name="tipDokumentaCombo" TabIndex="0" ItemsSource="{Binding Path=TipoviDokumenta}" SelectedValue="{Binding Path=Potvrda.Tip}" SelectedValuePath="Tip" SelectionChanged="tipDokumentaCombo_SelectionChanged" IsTextSearchEnabled="True" TextSearch.TextPath="Tip">
<ComboBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=Tip}" />
<TextBlock Text=" (" />
<TextBlock Text="{Binding Path=OpisDokumenta}" />
<TextBlock Text=")" />
</StackPanel>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
Disclaimer: I am not the original author. This answer is fabricated from the existing comments. Attribution should be given to #mersadk who post, most of this answer's details in the comments. I test it and verified that this works in my (similar) environment - issue.

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