WPF DataGrid - Problem Customizing a ComboBox - wpf

I have a Datagrid with a combo box bound column that works great as follows:
<tk:DataGridComboBoxColumn SelectedValueBinding="{Binding DefaultLocationID}"
SelectedValuePath="LocationID"
DisplayMemberPath="LocationName"
Header="Default Location"
ItemsSource="{Binding Source={StaticResource CustomerLocations}}">
</tk:DataGridComboBoxColumn>
Ultimately I want to customize the dropdown to show 'ID' and 'Name' together so a TemplateColumn seems to be the way to go. Starting small, I can't get the following simple example to work which should replace the standard DataGridComboBoxColumn. The dropdown appears fine, but when I 'select' a dropdown item, it does not accept and goes back to the previous value. I've tried variations on 'Mode=TwoWay' but no luck. Do I need a 'CellEditingTemplate' ?
DefaultLocationID is the foreign-key field being edited, while 'LocationID' is a column in 'CustomerLocations'.
<tk:DataGridTemplateColumn Header="Default Location">
<tk:DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<ComboBox VerticalAlignment="Top"
SelectedItem="{Binding LocationID, Mode=TwoWay}"
SelectedValue="{Binding DefaultLocationID, Mode=TwoWay}"
ItemsSource="{Binding Source={StaticResource CustomerLocations}}"
SelectedValuePath="LocationID"
DisplayMemberPath="LocationName" >
</ComboBox>
</DataTemplate>
</tk:DataGridTemplateColumn.CellTemplate>
Thanks!!

Can you post the relevant parts of your CustomerLocations resource? Can you also post the type of class that your grid is binding to?
Try removing the SelectedValuePath, DisplayMemberPath and SelectedValue from the ComboBox.
If you want to display multiple pieces of data in your combobox see the below XAML
<ComboBox ...>
<ComboBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding LocationId}"} />
<TextBlock Text=" - "/>
<TextBlock Text="{Binding LocationName}"} />
</StackPanel>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>

Related

Can't show the DataTemplate on a selected item in combobox?

Newbie question. In the following combobox, the drop-down list correctly displays the company name and phone number as per the DataTemplate. However, selecting an item from the drop-down (by mouse) resutls only in showing the object name:
Stargate_V.DataService.View_Small_Company
The selected company name and phone number is not shown. What am I doing wrong?
<ComboBox
ItemsSource="{Binding PrimaryInsurance.Companies}"
ItemTemplate="{StaticResource CompanyTemplate}"
IsEditable="True"
IsTextSearchEnabled="True"
Height="20" HorizontalAlignment="Left" Margin="375,235,0,0" VerticalAlignment="Top" Width="198" />
The CompanyTemplate is:
<DataTemplate x:Key="CompanyTemplate">
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Companyname}" Width="240"/>
<TextBlock Text="|" Width="10"/>
<TextBlock Text="{Binding Phone}" Width="80" />
</StackPanel>
</DataTemplate>
TIA
The issue that you are having is the combination of displaying a complex type (i.e. Class) with a DataTemplate and your ComboBox has IsEditable set to true. When setting IsEditable to true the ComboBox doesn't know which property to use for searching so it just calls ToString on the object and displays the results. To fix this issue you need to set the TextSearch.TextPath to the property name on the object that you would like to use for searching. Once you do that it will display that property in the selection box instead of the result of ToString. Below is what your XAML should look like if you wanted to search on the Companyname property on your object.
<ComboBox
ItemsSource="{Binding PrimaryInsurance.Companies}"
ItemTemplate="{StaticResource CompanyTemplate}"
IsEditable="True"
IsTextSearchEnabled="True"
TextSearch.TextPath="Companyname"
Height="20" HorizontalAlignment="Left" Margin="375,235,0,0" VerticalAlignment="Top" Width="198" />

Link textbox to combobox - not working

I have a WPF usercontrol with a combobox & textbox. I want the textbox to hold the value of the selected item in the combobox and it works fine if I use SelectedValue in the binding path. However if I try to use the Title column of the combobox (SelectedValue.Title) the value of the textbox is overwritten but nothing is displayed. Can anyone tell me what I am doing wrong? My code sample is below. I am a newbie at this so please be kind :)
<ComboBox x:Name="ComboProject" Grid.Column="4" Grid.Row="0" TabIndex="14"
ItemsSource="{Binding Source={StaticResource Projects}, XPath=./Project}"
SelectedValuePath="#Item"
Tag="Project Number"
TextSearch.TextPath="#Item">
<ComboBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text= "{Binding XPath= #Item}" Width="90" />
<TextBlock Text= "{Binding XPath= #Title}" Width="220" />
</StackPanel>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
<TextBox x:Name="loaded" Text="{Binding Path=SelectedValue.Title, NotifyOnSourceUpdated=True, ElementName=ComboProject}" Grid.Row="2" Grid.Column="4" Tag="Project Title" TabIndex="15"/>
You set SelectedValuePath="#Item", so that's what SelectedValue has right now. Try setting it to Title and binding directly to SelectedValue:
<ComboBox x:Name="ComboProject"
ItemsSource="{Binding Source={StaticResource Projects}, XPath=./Project}"
SelectedValuePath="#Title">
<ComboBox.ItemTemplate>
...
</ComboBox.ItemTemplate>
</ComboBox>
<TextBox Text="{Binding SelectedValue, ElementName=ComboProject}" />
I removed some other code for clarity of example.
EDIT :
Ok, if you want to use SelectedValue for other purposes we can bind TextBox to SelectedItem instead. If the Title is an attribute of a selected XML node, then we can access it like this:
<TextBox Text="{Binding SelectedItem.Attributes[Title].Value, Mode=OneWay, ElementName=ComboProject}" />

Multiselect ComboBox, Force it to always display the same text

I have a multiselect combobox that works fine. Except for the text. I want it to always have the same text ("Commodity Filter") regardless of what the user has selected.
If I set iseditable to true and the text to CommodityFilter it looks fine until the user makes a selection, then it is garbage (displays object type name). How can I hard code some text there? (Actually ideally i would databind it so it can change depending on whether anything is selected, but that would be a bonus at this point)
<ComboBox IsEditable="True" Text ="Commodity Filter" ItemsSource="{Binding Path=ActiveCommodities}">
<ComboBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<CheckBox IsChecked="{Binding IsSelected}"
Width="20" />
<TextBlock Text="{Binding Commodity}"
Width="100" />
</StackPanel>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
I ended up creating a custom object for populating the ComboBox (which had the IsSelected property and implemented INotifyPropertyChanged) because I was creating several comboboxes to control filtering. Once I did this is was trivial to override the tostring on the customobject and pass in the appropriate text. So the xaml did not change much.
I would have preferred to overlay with a text box but that seemed to be beyond my abilities to get a polished look in a reasonable time.
<ComboBox ItemsSource="{Binding Path=ActiveFuturesMonths}"
IsEditable="True"
IsReadOnly="True"
Text="Futures Month Filter" >
<ComboBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<CheckBox IsChecked="{Binding IsSelected}"
Width="20" />
<TextBlock Text="{Binding Text}"
Width="100" />
</StackPanel>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
Actually the crux is in setting -
IsEditable="True"
IsReadOnly="True"
Text="Futures Month Filter"
rather than creating custom object. thanks a lot it helped.

Lookup-id-control in WPF DataGrid

I am working with DataGrid. One column displays text, but the data behind this contains only an id. This id must somehow be converted to a string.
I need something like a combobox with the properties ItemsSource, DisplayMemberPath, SelectedValue and SelectedValuePath. But instead of a button displayed, there must be only a text. Is there some control for that?
That works (would like to exchange combobox with something that looks like textbox):
<DataGridTemplateColumn Header="Leistungsart" MinWidth="100">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<ComboBox ItemsSource="{Binding Source={StaticResource ResourceKey=viewModel}, Path=Leistungsarten}"
DisplayMemberPath="Bezeichnung"
SelectedValue="{Binding Path=BDELeistungsartID, Mode=OneWay, Converter={StaticResource ResourceKey=NullableInt2IntConverter}}"
SelectedValuePath="BDELeistungsartID"
IsEnabled="false"
IsEditable="False"
Height="35">
</ComboBox>
</DataTemplate>
Thanks a lot for your aswer. Yes, that with Template property worked for me:
<ComboBox ItemsSource="{Binding Source={StaticResource ResourceKey=viewModel}, Path=Leistungsarten}"
DisplayMemberPath="Bezeichnung"
SelectedValue="{Binding Path=BDELeistungsartID, Mode=OneWay, Converter={StaticResource ResourceKey=NullableInt2IntConverter}}"
SelectedValuePath="BDELeistungsartID">
<ComboBox.Template>
<ControlTemplate>
<Label Content="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=SelectedItem.Bezeichnung}"
Margin="0,0,0,0" Padding="0,0,0,0"/>
</ControlTemplate>
</ComboBox.Template>
</ComboBox>
You could use a ComboBox, but overwrite the Template property to show just a Label. You'll have to recreate the Click events too.
Easiest way would be to use a tool like Snoop or Blend and see what the default ComboBox template looks like, and modify that to what you want.

Accessing control between DataGridCells, dynamic cascading ComboBoxes

I have a DataGrid that two of its columns are ComboBoxes (one contains few but not this is the problem).
I want, that when the user changes the first Combo's value, the ComboBox in the other column should bind to a property of its (this property is a collection). Say the First ComboBox is Category, I want that when the user changes its value, the other CB is populated with the values of (first combo's selected category).Vendors.
How should I do it, I don't use MVVM, just simple WPF.
I don't know what should be the right way to implement it, I hope I started it right.
I think, if I could get the other ComboBox (which is located in a different DataGridCell) from the first's SelectionChangeHandler that would be the best, because then I can reset its source on each selection change of the first one.
Note that I have the capability of reaching the current (the first's) DataGridCell, I am just looking for an efficient way to access the right DataGridCell sibling and then get its child (second) combo.
Also note that the selected category should vary from row to row, and the second ComboBox should depend on this row's category.
I actually tried to implement it so that the CollectionViewSource.Source is bound to the current item (i.e. the row's DataContext) but it doesn't seem to work.
I prefer to set the second combo's CollectionViewSource (VendorsCollection) thru an Action trigger or handler at the 1st ComboBox's SelectionChange.
The other ComboBoxes in that field don't seem to make a problem as they're all bound to each other, I might use CollectionViewSource.Filter, anyway it's not a problem to access them as they are simple siblings, not like the first one which is a distant cousin located deep in another DataGridCell.
Here is what is what I tried so far:
<DataGrid>
<DataGrid.Resources>
<CollectionViewSource x:Key="CategoriesCollection" Source="{Binding Context.CategoriesList, Source={x:Static Application.Current}, IsAsync=True}" />
</DataGrid.Resources>
<DataGrid.Columns>
<DataGridTemplateColumn Header="Category">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock DataContext="{Binding Category}" Text="{Binding Title}"/>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
<DataGridTemplateColumn.CellEditingTemplate>
<DataTemplate>
<!--This is the first ComboBox-->
<ComboBox
IsSynchronizedWithCurrentItem="False"
ItemsSource="{Binding Source={StaticResource CategoriesCollection}}"
DisplayMemberPath="Title"
SelectionChanged="cbCategories_SelectionChanged"
SelectedItem="{Binding Category}"/>
</DataTemplate>
</DataGridTemplateColumn.CellEditingTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn Header="Style">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<StackPanel>
<TextBlock DataContext="{Binding Finish.Style.Vendor}" Text="{Binding Contact.Title}"/>
<TextBlock DataContext="{Binding Finish.Style}" Text="{Binding Title}"/>
<TextBlock Text="{Binding Finish.Title}"/>
</StackPanel>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
<DataGridTemplateColumn.CellEditingTemplate>
<DataTemplate>
<StackPanel>
<StackPanel.Resources>
<!--I want, that when the user selects a value in the first ComboBox,
the VendorsCollection below should be populated with the selected Category.Vendors,
or alternatively current row's data item.Category.Vendors,
I just donno how to access current row from these resources.-->
<CollectionViewSource x:Key="VendorsCollection" Source="{Binding Vendors, Source={StaticResource CategoriesCollection}}" />
<CollectionViewSource x:Key="StylesCollection" Source="{Binding Styles, Source={StaticResource VendorsCollection}}" />
<CollectionViewSource x:Key="FinishesCollection" Source="{Binding Finishes, Source={StaticResource StylesCollection}}" />
</StackPanel.Resources>
<ComboBox
IsSynchronizedWithCurrentItem="True"
ItemsSource="{Binding Source={StaticResource VendorsCollection}}"
SelectedItem="{Binding Finish.Style.Vendor}"
DisplayMemberPath="Contact.Title"/>
<ComboBox
IsSynchronizedWithCurrentItem="True"
ItemsSource="{Binding Source={StaticResource StylesCollection}}"
SelectedItem="{Binding Finish.Style}"
DisplayMemberPath="Title"/>
<ComboBox
IsSynchronizedWithCurrentItem="True"
ItemsSource="{Binding Source={StaticResource FinishesCollection}}"
SelectedItem="{Binding Finish}"
DisplayMemberPath="Title"/>
</StackPanel>
</DataTemplate>
</DataGridTemplateColumn.CellEditingTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
I just came across your questions. Did you get your problem resolved? I think your question is similar to this one I got. Hope the solution there helps you too.

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