i just started learning WPF as i am moving on from WinForm. At the moment i am having difficulties displaying bind data from class to tree view.
My tree view works perfectly if i use .Items.Add() method but when it comes to binding class data to TreeView this is what i see:
Here is the c# code:
public MainWindow()
{
InitializeComponent();
Search sc = new Search();
sc.query(null, "");
this.DataContext = sc;
}
Here is the xaml
<TreeView Width="400" Height="500" Name="TreeViewB" ItemsSource="{Binding getTreeResults}" Style="{StaticResource myTreeView}">
<TreeView.ItemTemplate>
<HierarchicalDataTemplate ItemsSource="{Binding Network}">
<TextBlock Text="{Binding getNetwork}"/>
</HierarchicalDataTemplate>
</TreeView.ItemTemplate>
Edited - 2 class added
Here is my class A
class Social_Searcher
{
List<Social_Network> networks = new List<Social_Network>();
public List<Social_Network> getTreeResults { get { return networks; } }
}
Here is my class B
class Social_Network
{
private string network_name;
private List<Keypair> data;
public Social_Network()
{
data = new List<Keypair>();
}
public struct Keypair
{
public void add(string _name, string _value)
{
name = _name;
value = _value;
}
public string name, value;
}
public string Network
{
get { return network_name; }
set { network_name = value; }
}
public void add(string name, string value)
{
if (name == "network")
{
network_name = value;
}
Keypair kp = new Keypair();
kp.add(name, value);
data.Add(kp);
}
public string getNetwork()
{
return network_name;
}
public List<Keypair> getData()
{
return data;
}
public string findKey_value(string key)
{
foreach (Keypair kp in data)
{
if (kp.name == key) return kp.value.ToString();
}
return "null";
}
}
You don't give much code, but getTreeResults and getNetwork look like methods, and your TextBlock will not know how to present them (normally, it would use the results of ToString(), but I don't know if that will work with a method.
If you want those methods, you can try it this way:
public string TreeResults { get { return sc.getTreeResuls(); }}
and then
<TreeView ... ItemsSource={Binding TreeResults} ... > ...
The same goes for getNetwork. I.e., you wrap each method in a public property.
If you don't want to do that, or can't, you can use an IValueConverter
There is clearly something going on in your UI, but it's hard to tell what exactly.
You will likely find a debugging tool such as Snoop useful, as it will allow you to click on items in your UI and see how they exist in the logical tree. You can modify their properties while the program is running to experiment and learn what you need to change in your source code.
I ran into this issue when converting a Windows Forms application to WPF. I know it sounds ridiculous, but make sure that your value is stored in the TreeViewItem's "Header" property, NOT the "Name" property. Once I did this, my list populated as expected.
Related
I have searched Google for a simple solution to this but no luck. I have a standard WPF combo box which I would simply like to be able to filter the list displayed according to the first 2 or 3 letters a users types when the combo box has focus. I tried some coding including some lamba expressions but the error "System.NotSupportedException" keeps getting thrown on the line where "combobox.Items.Filter" is specified. I'm not using MVVM and would just like this simple functionality available for the user. Please help! P.S. IsEditable, IsTextSearchEnabled and StaysOpenOnEdit properties are set to true but the desired functionality is not yet achieved.
I have developed a sample application. I have used string as record item, you can do it using your own entity. Backspace also works properly.
public class FilterViewModel
{
public IEnumerable<string> DataSource { get; set; }
public FilterViewModel()
{
DataSource = new[] { "india", "usa", "uk", "indonesia" };
}
}
public partial class WinFilter : Window
{
public WinFilter()
{
InitializeComponent();
FilterViewModel vm = new FilterViewModel();
this.DataContext = vm;
}
private void Cmb_KeyUp(object sender, KeyEventArgs e)
{
CollectionView itemsViewOriginal = (CollectionView)CollectionViewSource.GetDefaultView(Cmb.ItemsSource);
itemsViewOriginal.Filter = ((o) =>
{
if (String.IsNullOrEmpty(Cmb.Text)) return true;
else
{
if (((string)o).Contains(Cmb.Text)) return true;
else return false;
}
});
itemsViewOriginal.Refresh();
// if datasource is a DataView, then apply RowFilter as below and replace above logic with below one
/*
DataView view = (DataView) Cmb.ItemsSource;
view.RowFilter = ("Name like '*" + Cmb.Text + "*'");
*/
}
}
XAML
<ComboBox x:Name="Cmb"
IsTextSearchEnabled="False"
IsEditable="True"
ItemsSource="{Binding DataSource}"
Width="120"
IsDropDownOpen="True"
StaysOpenOnEdit="True"
KeyUp="Cmb_KeyUp" />
I think the CollectionView is what you are looking for.
public ObservableCollection<NdfClassViewModel> Classes
{
get { return _classes; }
}
public ICollectionView ClassesCollectionView
{
get
{
if (_classesCollectionView == null)
{
BuildClassesCollectionView();
}
return _classesCollectionView;
}
}
private void BuildClassesCollectionView()
{
_classesCollectionView = CollectionViewSource.GetDefaultView(Classes);
_classesCollectionView.Filter = FilterClasses;
OnPropertyChanged(() => ClassesCollectionView);
}
public bool FilterClasses(object o)
{
var clas = o as NdfClassViewModel;
// return true if object should be in list with applied filter, return flase if not
}
You wanna use the "ClassesCollectionView" as your ItemsSource for your Combobox
Due to architecture design specifications, I have an application that fills its views from ClassLibraries. The application itself behaves like a sort of Integrator.
Now I need to add localization resources and I can successfully achieve it by adding *.resw files but only if the control is declared inside of the Application project.
What I actually need is to being able to share those resources across the ENTIRE SOLUTION somehow.
Then, the point is to being able to translate any control's content of the solution by using localization resources, preferably using the structure explained above.
For example, I have this following view, which fills the TextBlocks' content depending on the selected language:
<ComboBox x:Name="Languages"
ItemsSource="{Binding Languages}"
SelectedItem="{Binding SelectedLanguage, Mode=TwoWay}">
<i:Interaction.Behaviors>
<iCore:EventTriggerBehavior EventName="SelectionChanged">
<iCore:InvokeCommandAction Command="{Binding ChangeLanguage}" />
</iCore:EventTriggerBehavior>
</i:Interaction.Behaviors>
<ComboBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding LanguageName}" />
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
<TextBlock Text="{Binding Model.HelloText}" FontSize="50" Foreground="Red"/>
<TextBlock Text="{Binding Model.HowAreYouText}" FontSize="50" Foreground="Red"/>
<BFview:BFView />
</StackPanel>
Where BFView is a view stored in another project (has two dummy textblocks also)
The Model of that view:
public class MainModel : TranslatableStrings
{
private string helloText, howareuText;
public string HelloText
{
get { return this.helloText; }
set { SetProperty(ref this.helloText, value); }
}
public string HowAreYouText
{
get { return this.howareuText; }
set { SetProperty(ref this.howareuText, value); }
}
}
And the base class of the Model is just a contractual class since it has no implementation, but a base type:
public abstract class TranslatableStrings : BindableBase { }
Then, the View data context is the following one:
public class MainViewModel : BaseViewModel
{
private ObservableCollection<MainViewListRscs> languages = new ObservableCollection<MainViewListRscs>();
private ICommand changeLang;
private MainModel model = new MainModel();
public MainViewModel()
{
Languages = new ObservableCollection<MainViewListRscs>()
{
new MainViewListRscs { LanguageCode = "es-ES", LanguageName = "Español" },
new MainViewListRscs { LanguageCode = "en-EN", LanguageName = "English" },
new MainViewListRscs { LanguageCode = "fr-FR", LanguageName = "Français" },
new MainViewListRscs { LanguageCode = "de-DE", LanguageName = "Deutsch" }
};
}
public ICommand ChangeLanguage
{
get { return changeLang = changeLang ?? new DelegateCommand(OnChangeLanguageRequested); }
}
public ObservableCollection<MainViewListRscs> Languages
{
get { return this.languages; }
set
{
this.languages = value;
OnPropertyChanged();
}
}
public MainViewListRscs SelectedLanguage { get; set; }
public MainModel Model
{
get { return this.model; }
set { this.model = value; }
}
private void OnChangeLanguageRequested()
{
Logger.Debug("MAINVIEW", SelectedLanguage.LanguageName + " selected.");
TranslateManager.UpdateStrings<TranslatableStrings>(SelectedLanguage.LanguageCode, this.Model);
}
public override Task OnNavigatedFrom(NavigationEventArgs args)
{
return null;
}
public override Task OnNavigatedTo(NavigationEventArgs args)
{
return null;
}
}
And the TranslateManager:
public class TranslateManager
{
public async static void UpdateStrings<T>(string langCode, T instance) where T : TranslatableStrings
{
//Get all the classes that implement TranslatableStrings
var currentAssembly = instance.GetType().GetTypeInfo().Assembly;
var translatableClasses = currentAssembly.DefinedTypes.Where(type => type.BaseType == typeof(T)).ToList();
//Open RESX file
ResourceLoader resx = ResourceLoader.GetForCurrentView(langCode);
foreach(var Class in translatableClasses)
{
foreach(var property in Class.DeclaredProperties)
{
string value = resx.GetString(property.Name);
var vmProp = instance.GetType().GetTypeInfo().GetDeclaredProperty(property.Name);
vmProp.SetValue(instance, value);
}
}
}
}
I have achieved changing the two TextBlocks of the MainView but not the view in another project. What I would need to do is to get a list of assemblies contained in a solution. I guess that getting just this would make everything work since I'm using a generic implementation.
Any suggestion will be much appreciated.
Thanks!
Your translation files are loaded as resources. So you can access them anywhere, even in other projects by doing something like
private ResourceLoader _resourceLoader = new ResourceLoader();
var someTranslation =_resourceLoader.GetString("your_localization_key");
Wrap this code nicely into a lib so that you can have an easy access to it from everywhere, and there you go !
i hope you can help me, because I've an very special question.
I have an View with an Datagrid. The DataContext I generate Dynamically. This is done by resolving some Interface (lets say IMyDataContext) over MEF.
This Interface has some Properties. The interesting Property for this problem is
ICollection Data {get;}
This Property is Implemented in the Backend by an ObservableCollection of an type which is known in the class which implements the Interface.
Now the Problem is, that the DataGrid don't Generate the columns. Even if I Listen to the IPropertyChanged Event of the Specific Class and then Update the Layout. Nothing changes.
So my Question is, how can I resolve this Issue?
Or is there an better Solution for my Problem?
I also tried to make the Interface Generic so that it looks like the following:
public Interface IMyDataContext<CollectionType>
{
ObservableCollection<CollectionType> Data {get;}
}
The Implementing Class Exports then with [Export(typeof(IMyDataContext<>)] or [Export(typeof(IMyDataContext<object>)]
and the class which registers the View with the DataContext via PRISM resolves them with [ImportMany(typeof(IMyDataContext<object>)] but this don't work with an ObservableCollection.
So this is why I declared the Collection as ICollection in the Interface.
Can someone explain me why it's not generating the Columns?
The Code for Binding in the View:
<DataGrid
ItemsSource="{Binding Data, UpdateSourceTrigger= PropertyChanged}"
CanUserAddRows="False"
CanUserDeleteRows="False"
AutoGenerateColumns="True"
ClipboardCopyMode="IncludeHeader" />
// Edit:
I've checked that the Data are there. And yes they are available in the View. Other ViewElements which binds also on this Data Field works perfectly. And they are directly below the Datagrid.
Example (Pseudo Code):
<DataGrid ItemsSource="{Binding Data}" /> <!-- Dont work -->
<Label Content="No Data Available" IsVisible="{Binding Data, Convert={StaticResource CollectionIsEmptyToVisibleConverter}" /> <!-- Work -->
For Information:
I fill the collection at once in an other Thread. But to be Thread Safe I Use the Dispatcher like this:
var items = new List<MyItemType>(); // MyItemType is an Class. this class I want to Display in the Datagrid
// ... fill items
Application.Current.Dispatcher.Invoke(new Action(() => this.Data = new ObservableCollection<MyItemType>(items)));
// Edit 2:
Ok, here is a code Example:
The Interface which i Mean:
public interface IDataContextInterface: INotifyPropertyChanged
{
ICollection Data { get; }
// ... Some other Properties
}
An Example Implementation of the Interface (I have multiple Implementations):
[Export(typeof(IDataContextInterface))]
public class ExampleDataContext1 : IDataContextInterface
{
private ObservableCollection<MyExampleDatagridEntry> _data;
public ObservableCollection<object> Data
{
get
{
return this._data;
}
set
{
if (this._data == value)
{
return;
}
if (value == null)
{
this._data = null;
RaisePropertyChanged("Data");
return;
}
var values = value.OfType<MyExampleDatagridEntry>();
if (values != null)
{
this._data = new ObservableCollection<MyExampleDatagridEntry>(values);
}
else
{
this._data = null;
}
RaisePropertyChanged("Data");
}
}
// Will be called in an Background Thread
public void Update()
{
var data = new ObservableCollection<MyExampleDatagridEntry>();
// .. fill the data
Application.Current.Dispatcher.Invoke(new Action(() =>
this._data =data));
}
}
The Data for this Example Model looks like:
public class MyExampleDatagridEntry : INotifyPropertyChanged
{
private _exampleString1;
public string ExampleString1
{
get
{
return this._exampleString1;
}
set
{
if (this._exampleString1 != value)
{
this._exampleString1 = value;
RaisePropertyChanged("ExampleString1");
}
}
}
private _exampleString2;
public string ExampleString2
{
get
{
return this._exampleString2;
}
set
{
if (this._exampleString2 != value)
{
this._exampleString2 = value;
RaisePropertyChanged("ExampleString2");
}
}
}
// .. Some other Properties
}
The Module which import all of them and register an new View to the Region (I don't know if there is a better way):
[ModuleExport(typeof(MyViewModule))]
public class MyViewModule : IModule
{
private ObservableCollection<IDataContextInterface> _dataContextModels;
private IRegionManager _regionManager;
[ImportingConstructor]
public MyViewModule(IRegionManager regionManager)
{
this._regionManager = regionManager;
this.DataContextModels.CollectionChanged += (s, e) => this.UpdateViews();
}
[ImportMany(typeof(IDataContextInterface))]
public ObservableCollection<IDataContextInterface> DataContextModels
{
get
{
return this._dataContextModels ?? (this._dataContextModels = new ObservableCollection<IDataContextInterface>());
}
set
{
this._dataContextModels = value;
this.UpdateViews();
}
}
private void UpdateViews()
{
foreach (var dataContext in this.DataContextModels)
{
// Short version of it. Normally i check if its registered
var view = new MyViewForDataContext{ dataContext = dataContext };
this._regionManager.Regions["MyRegion"].Add(view);
}
}
}
And finally the View looks like this (Shorten to have it simpler):
<UserControl x:Class="MyViewForDataContext">
<!-- Some Other stuff here -->
<Grid>
<!-- This Datagrid don't generate the Columns -->
<DataGrid ItemsSource="{Binding Data}" AutoGenerateColumns="True" />
<!-- This one works -->
<Label Content="No Data Available" Visibility={Binding Data, Converter={StaticResource EmptyListToVisiblityConverter}} />
</Grid>
</UserControl>
// Edit 3 (Solution):
Ok I finally solved it. It was an Problem by my behavior which I bound to the Datagrid. In this Behavior I tried to refresh the Datagrid, which worked fine. But not if the ItemsSource is null of the Datagrid. For this reason i had to insert an null check of the ItemsSource.
I am trying to use the following code example from the Infragistics site and I'd like edits in the XamDataCards to be reflected in the XamDataGrid. However, my DataSource for the XamDataGrid is an ObservableCollection<Companies> in my ViewModel. How can I also bind to the card and relay updates back to my Companies object in the ViewModel?
<igDP:XamDataGrid x:Name="dgCompanies" Theme="IGTheme" DataSource="{Binding Companies}" SelectedDataItemsScope="RecordsOnly">
<igDP:XamDataGrid.FieldSettings>
<igDP:FieldSettings CellClickAction="SelectCell" AllowEdit="True"/>
</igDP:XamDataGrid.FieldSettings>
</igDP:XamDataGrid>
<igDP:XamDataCards x:Name="XamDataCards1"
Grid.Row="1"
DataSource="{Binding Path=SelectedDataItems, ElementName=dgCompanies}"
Theme="IGTheme">
Edit: Added ViewModel
public class CompanyMgmtViewModel : ViewModelBase
{
private ObservableCollection<Object> _Companies = null;
public ObservableCollection<Object> Companies
{
get { return _Companies; }
set
{
if (_Companies != value)
{
_Companies = value;
RaisePropertyChanged(GetPropertyName(() => Companies));
}
}
}
public CompanyMgmtViewModel()
{
this.LoadData();
}
public void LoadData()
{
ObservableCollection<Object> records = new ObservableCollection<Object>();
var results = from res in AODB.Context.TCompanies
select res;
foreach (var item in results)
if (item != null) records.Add(item);
Companies = records;
}
}
The Model/Context code is just EF Database First generated.
You would need to bind your XamDataGrid's SelectedDataItems property to a property of type object[] ie. SelectedCompanies in your ViewModel and bind to that for your XamDataCards' datasource.
The accepted answer in this thread has a sample that shows how to do this, albeit with a ListBox instead of XamDataCards:
http://www.infragistics.com/community/forums/t/89122.aspx
Just replace that ListBox with your XamDataCards control, it works and updates the XamDataGrid. The ViewModel in the example is contained in the MainWindow code-behind, so it is MVVM like you want.
more info:
http://help.infragistics.com/Help/Doc/WPF/2014.1/CLR4.0/html/xamDataGrid_Selected_Data_Items.html
IG's SelectedDataItems is an object[] :
http://help.infragistics.com/Help/Doc/WPF/2014.1/CLR4.0/html/InfragisticsWPF4.DataPresenter.v14.1~Infragistics.Windows.DataPresenter.DataPresenterBase~SelectedDataItems.html
I couldn't have gotten to this answer without Theodosius' and Ganesh's input - so thanks to them, they both had partial answers.
I first tried to bind the SelectedDataItems of the XamDataGrid to the XamDataCards by way of a property on the ViewModel as Theodosius suggested, but that wasn't enough. Thanks to Ganesh, I implemented INotifyPropertyChanged on my model objects, by inheriting from ObservableObject in MVVMLight (how did I not know the Model needed this?).
Below are the relevant pieces of code to make it work.
I also implemented PropertyChanged.Fody as documented here; that's where the TypedViewModelBase<T> and removal of RaisePropertyChanged() comes from.
I'm also creating my Model objects by using a LINQ/Automapper .Project().To<T>() call which can be found here.
Model
public class Company : ObservableObject
{
public Company() { }
public int id { get; set; }
public string strName { get; set; }
public string strDomicileCode { get; set; }
}
ViewModel
public class CompanyMgmtViewModel : TypedViewModelBase<Company>
{
private ObservableCollection<Object> _Companies = null;
private Object[] _selectedCompany = null;
public Object[] Company
{
get { return _selectedCompany; }
set
{
if (_Company != value)
{
_selectedCompany = value;
}
}
}
public ObservableCollection<Object> Companies
{
get { return _Companies; }
set
{
if (_Companies != value)
{
_Companies = value;
}
}
}
public CompanyMgmtViewModel()
{
this.LoadData();
}
public void LoadData()
{
ObservableCollection<Object> records = new ObservableCollection<Object>();
var results = AODB.Context.TCompanies.Project().To<Company>();
foreach (var item in results)
if (item != null) records.Add(item);
Companies = records;
}
}
View
<igDP:XamDataGrid x:Name="dgCompanies"
Theme="IGTheme"
DataSource="{Binding Companies, Mode=OneWay}"
SelectedDataItemsScope="RecordsOnly"
SelectedDataItems="{Binding Company}">
...
<igDP:XamDataCards x:Name="XamDataCards1"
Grid.Row="1"
DataSource="{Binding ElementName=dgCompanies, Path=SelectedDataItems}"
Theme="IGTheme">
I'm new to WPF and trying to wrap my head around the preferred way to handle data. I found this link that explains the databinding for a tree view. I have tried to create my code in a similar way, but I can't see why that code runs fine and mine doesn't.
Anyway, I've defined some class for artists/albums/songs
class LibArtist
{
public string Name { get { return mName; } }
string mName;
public ObservableCollection<LibAlbum> Albums;
public LibArtist(string name)
{
mName = name;
Albums = new ObservableCollection<LibAlbum>();
}
}
class LibAlbum
{
public string Name { get { return mName; } }
public string Artist { get { return mArtist.Name; } }
public uint Year { get { return mYear; } }
public ObservableCollection<LibSong> mSongs = new ObservableCollection<LibSong>();
uint mYear;
LibArtist mArtist;
string mName;
public LibAlbum(string pName, LibArtist pArtist, uint pYear)
{
mName = pName;
mArtist = pArtist;
mYear = pYear;
}
}
class LibSong
{
public string Title { get { return mName; } }
public string Artist { get { return mArtist; } }
public string Album { get { return mAlbum; } }
public string Location { get { return mLocation; } }
public uint Year { get { return mYear; } }
string mName;
uint mYear;
string mAlbum;
string mArtist;
string mLocation;
public LibSong(string pSongLocation)
{
mLocation = pSongLocation;
TagLib.File lFile = TagLib.File.Create(pSongLocation);
mAlbum = lFile.Tag.Album;
mName = lFile.Tag.Title;
mArtist = lFile.Tag.AlbumArtists.Length > 0 ? lFile.Tag.AlbumArtists[0] : "???";
//use tag lib to fill the data if this file exists
mYear = lFile.Tag.Year;
}
public override bool Equals(object obj)
{
LibSong temp = obj as LibSong;
if (temp == null)
return false;
if (temp.Location == this.Location)
return true;
if (temp.Artist == this.Artist && temp.Album == this.Album && temp.Year == this.Year)
return true;
return false;
}
}
And these sit in a library class:
class Library
{
public SortedDictionary<string, List<string>> mArtistsToAlbums;
SortedDictionary<string, List<LibSong>> mAlbumsToSongs;
public List<LibSong> mSongList;
public ObservableCollection<LibSong> mSongList2;
public ObservableCollection<LibAlbum> mAlbumList;
public ObservableCollection<LibArtist> mArtistList;
...
}
In my main window, I set the data context of my treeview to the library object:
public MainWindow()
{
mPlayer = new izPlayer(0);
InitializeComponent();
libraryTreeView.DataContext = mLibrary;
mLibrary = new Library();
mLibrary.CreateTestData();
In my xaml, I define the treeview like so:
<TreeView Name="libraryTreeView"
HorizontalAlignment="Left"
ItemsSource="{Binding mArtistList}"
Height="443" Margin="10,50,0,0" VerticalAlignment="Top" Width="344" MouseDoubleClick="libraryTreeView_MouseDoubleClick"
>
<TreeView.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Name}" />
</DataTemplate>
</TreeView.ItemTemplate>
</TreeView>
And when I run this, I don't get anything displayed in the treeview. As I said, I'm not sure why this is different from the example code, or why it isn't displaying the data inside mArtistList.
Any help would be appreciated!
Specifically for the TreeView Dennis' answer is a great resource. If you're not getting any items even in at the top level thought, it may be due to invalid binding sources. It looks like Library is declaring public fields
public ObservableCollection<LibArtist> mArtistList;
In order to use binding in the XAML these sources need to be public properties
public ObservableCollection<LibArtist> mArtistList { get; set; }
This is totally different from example code (I mean XAML difference).
The main concept for the data-bound TreeView in WPF is that you must describe hierarchical data templates for your nodes, because you want to display hierarchical data.
Your XAML should look like this:
<TreeView.Resources>
<HierarchicalDataTemplate DataType="{x:Type yourNamespace:LibArtist}" ItemsSource="{Binding Albums}">
<!-- the template tree for displaying artist's data -->
</HierarchicalDataTemplate>
<HierarchicalDataTemplate DataType="{x:Type yourNamespace:LibAlbum}" ItemsSource="{Binding Songs}">
<!-- the template tree for displaying song's data -->
</HierarchicalDataTemplate>
<!-- and so on -->
</TreeView.Resources>