Is there any way bind textboxes to the row of a dataset that is selected in a combobox? For example I have a dataset with 2 columns, one called name (this is the primary key) and the other is called author. I would like to set up databinding so that when the user selects the name in the combobox the corresponding author appears in the text of a textbox.
Specifically I want to know if this can be done through databinding or if it will require code for the selecteditemchanged event, or if it should be done using a value converter.
I think it would be possible to do with a value converter, but I was hoping it could be accomplished entirely in XAML.
This turned out to be a good tutorial to follow for building the appropriate code using the visual studio wizards for all the data stuff.
http://msdn.microsoft.com/en-us/library/dd547149.aspx
Try this:
<TextBox Text="{Binding ElementName=comboboxName, Path=SelectedItem.author}" />
comboboxNameis Name attribute of your ComboBox
.author is field name
Yes you bind to ElementName and then for path SelecteItem.PropertyName. Search MSDN on .NET Binding ElementName.
Related
i've got a textbox which text is binded to a listview selecteditem as follows:
<TextBox x:Name="txtAdditional" Width="300" Text="{Binding ElementName=lstPersons, Path=SelectedItem.Additional, Mode=OneWay}" />
Now i like to implement a mechanism to add new items to the listview using this textbox to get the actual data. So i would like to bind the text of the textbox to a property of the viewmodel so it can be processed by a command.
So it the textboxes text has to be binded to the listviews selecteditem and additionally to a property of my viewmodel.
I've searched around and found some approaches but i can't help to think that there should be some simpler mechanism to archive this goal.
What I found by now:
Using MultiBindung with some kind of ValueConverter? So it seems to me that this is primary for displaying and not for updating a viewmodels property.
The use of some selfdefined custom control?
The use of an BindingProxy with in- and out-dependencyproperties like in Impossible WPF Part 1: Binding Properties?
Is there another, simpler solution to this or would i have to use one of those above?
And if one should use one of those approaches, which one whould you choose?
I can't help but thinking that this issue hasn't been given some thoughts already, using an mvvm pattern?! ;-)
yes thanks to the hint from BionicCode.
We, or better I should have to think the MVVM concept out. Of course no - or at least as little code behind as possible.
I added the property "selectedPerson" to my viewmodel and bound the SelectedItem of the listview to this property. So the object related properties were at hand directly through the "selected" object in my viewmodel and there was no need anymore to access the textbox content at all.
Thanks to BionicCode for the hint!
I'm learning WPF and am really trying to drill down on binding until I can do it like a boss. But I'm having a bit of an issue.
In xaml, I have a ListBox like so:
<ListBox Name="AccountsDisplay"
SelectedValuePath="Username"
IsSynchronizedWithCurrentItem="True"
ItemsSource="{Binding Accounts}"
/>
And I have a TextBox that's pulling "Username" from said ListBox.
<TextBox Text="{Binding ElementName=AccountsDisplay, Path=SelectedValue}"/>
Note: Accounts is both an ObservableCollection and all objects added to it are of type Account, which is purely a data class that extends INotifyPropertyChanged, and has properties such as Username, Password, etc.
The TextBox is pulling the Username property properly, and updates any time I change selection in the ListBox (which is populated with pretty lil' Account info entries, as intended), but I cannot then click on the TextBox and attempt to update the Username portion of entries in the ListBox.
My gut tells me I'm going about this TextBox the wrong way, since I won't be able to make other TextBoxes and pull any additional Account properties (thanks to SelectedValuePath already having a value), but I'm too new to WPF & XAML to see where the error is in my ways!
Am I barking up the right tree, or is there a more appropriate way to get a TextBox to synchronize with (and edit) the data in another UI Element?
Consider binding to the property of the actual DataContext of the list item selected.
I do not use SelectedValue because I am not sure of it's purpose.
Because of my ignorance regarding the use of that particular property, I just rely on SelectedItem.
I can then specify the property name that I want to bind to relative to the DataContext of the selected list item.
<TextBox Text="{Binding ElementName=AccountsDisplay, Path=SelectedItem.Username}"/>
I have a ChildWindow that has a Listbox. I have an enum for checking which table I want to load. I am basically reusing this child window to load many different tables from my Entity model via a CollectionViewSource. I am using the ItemTemplate and cannot bind simply to the Text property due to the dynamic field name of the various tables. I used to just set the DisplayMemberPath or set the Text via binding when using one table. How do I achieve this with Binding inside of the ItemTemplate? Can I make a property in code-behind and then just set that property, then bind to this property. I am not sure what the syntax would be for this kind of binding and not sure how to search for it. Thanks...
VS 2010, Silverlight 5.0
I have a WPF Data Grid bound to an observable collection, which is working as intended.
What I am trying to do now is add text below it to say: "Number of selected rows: {count goes here}"
What's the proper way to do this? I could add a new property in the View Model called SelectedCount or something similar and bind to that, but it doesn't feel right. It seems redundant. Also, I could set the label text dynamically in the code behind, but I'm not sure if that's the "right" place to do this either.
Here's an example below.
EDIT:
Please pretend there's a checkbox column header whose intention is to provide check/uncheck all functionality. The state of this header checkbox should not count towards the final count.
You could use element binding to declaratively bind to the SelectedItems.Count property in XAML:
<TextBlock Text="{Binding ElementName=MyDataGrid,
Path=SelectedItems.Count, StringFormat=Number of selected rows: {0}}" />
Update
Presumably you're using MVVM, so adding a SelectedXCount property to your view model is a perfectly reasonable application of the view model. The advantage of having it in the view model is that you could unit test based on the number of selected items. E.g. if you want to check that the user can only progress (a CanNext property returns true) if the user has selected some items.
The SelectedItems property is not a DependencyProperty so can't be bound to, but there are many articles online that get around the issue when using the DataGrid in MVVM. Most of the solutions involve using a mechanism for calling a view model command on the invocation of the DataGrid's SelectionChanged event.
I am trying to develop a filtering functionality for WPF DataGrid (from the WPF Toolkit). I want a user to right-click any cell and select Filter from its CcontextMenu, and then the grid should be filtered by the cell's value.
I am trying the M-V-VM pattern. My windows's datacontext is MainWindowViewModel which has a property Transactions. This property returns ObservableCollection<TransactionViewModel>, and the data grid uses this collection as its items source. So basically each row is bounded to TransactionViewModel (as you can guess, this grid lists transactions). MainWindowsViewModel has ICollectionView which is used for filtering and tracking the currently selected row. The DataGrid has its property IsSynchronizedWithCurrentItem set to "true", so myCollectionView.CurrentItem gives me the currently selected TransactionViewModel.
The only thing I still need to know is by which column I need to filter. This depends on where the user clicked the context menu. So I am trying to pass this information using CommandProperty of the context menu item. And here I have a real problem. I tried this:
CommandParameter="{Binding Column.Binding.Path.Path,
RelativeSource={RelativeSource FindAncestor,
AncestorType={x:Type tk:DataGridCell}}}" />
This is really ugly, but this works for DataGridTextColumns. Unfortunately, I have also DataGridTemplateColumns, and they don't work (the path is different there, because I need to reach the actual cell template)...
So how can I implement this functionality? Perhaps the whole way is wrong? I didn't find any valuable example on that. The only thing I found is the WPF DataGrid autofilter implementation on the Codeproject which doesn't work at all for some reason...
Thank you.
I'm not 100% sure if this would help but...
DataGrid has CurrentCell so you could bind it in TwoWay mode in your MainWindowViewModel.
Then every "row" could point to DoFilter command defined in MainWindowViewModel. It's not a beauty solution (because viewmodel has to know DataGrid Cell type) but it should work.
Why not just pass the cell as a parameter like this:
CommandParameter=
"{Binding RelativeSource={RelativeSource FindAncestor,tk:DataGridCell,1}}" />
and let your command's Executed event handle all the hard part of finding the actual column name? That way you can write all the special-case code you need.