I'm using Prism for MVVM pattern in my WP7 app. In my ViewModel I implemented two properties:
private IconVO _selectedIcon;
public IconVO SelectedIcon {
get {
return _selectedIcon;
}
set {
_selectedIcon = value;
SelectedIconCanvas = _selectedIcon.Icon;
RaisePropertyChanged(() => this.SelectedIcon);
}
}
private Canvas _selectedIconCanvas;
public Canvas SelectedIconCanvas {
get {
return _selectedIconCanvas;
}
set {
_selectedIcon = value;
RaisePropertyChanged(() => this.SelectedIconCanvas);
}
}
where IconVO (it stores single icon information loaded from some XML file):
public class IconVO {
public string Name { get; set; }
public Canvas Icon { get; set; }
}
SelectedIcon is currently selected IconVO from ObservableCollection<IconVO> (collection is binded to ListPicker).
SelectedIconCanvas is a property which stores Canvas from SelectedIcon.Icon.
When I execute this code, application throws the ArgumentException -> The parameter is incorrect on this line:
RaisePropertyChanged(() => this.SelectedIconCanvas);
What's wrong with this code?
Thanks, fl4izdn4g
EDIT 01-02-2012
Here is XAML as you requested:
<Border Grid.Row="1" Background="{Binding SelectedColor}" >
<ContentControl Margin="40,20,300,20" Content="{Binding SelectedIconCanvas}">
<ContentControl.ContentTemplate>
<DataTemplate>
<ContentPresenter />
</DataTemplate>
</ContentControl.ContentTemplate>
</ContentControl>
</Border>
I've tried to replace ContentControl with:
<Button Content="{Binding SelectedIconCanvas}"/>
but it didn't help.
You should not have a UI element mentioned in a view model in MVVM. Maybe you want to reference the DataContext/view model of the selected canvas?
Just put this:
private IconVO _SelectedIcon;
public IconVO SelectedIcon
{
get { return _SelectedIcon; }
set
{
_SelectedIcon = value;
SelectedIconCanvas = _SelectedIcon.Icon;
RaisePropertyChanged("SelectedIcon");
}
}
private Canvas _SelectedIconCanvas;
public Canvas SelectedIconCanvas
{
get { return _SelectedIconCanvas; }
set
{
_SelectedIconCanvas = value;
RaisePropertyChanged("SelectedIconCanvas");
}
}
Sorry I changed your Properties Names (I have the C# preference)
Related
I have a ListBox containing Name. Now I need to select multiple items from ListBox.
ViewModel.CS
private Person selectedListOfPeople_;
public Person SelectedListOfPeople
{
get
{ return selectedListOfPeople_;}
set
{ this.SetProperty(ref selectedListOfPeople_, value, nameof(SelectedListOfPeople));}
}
private ObservableCollection<Person> listOfPeople_;
public ObservableCollection<Person> ListOfPeople
{
get { return listOfPeople_; }
set
{
this.SetProperty(ref listOfPeople_, value, nameof(ListOfPeople));
}
}
public ShellViewModel()
{
ListOfPeople = new ObservableCollection<Person>
{
new Person("ABC"),new Person("DEF"),new Person("GHI"),new Person("JKL")
};
}
public class Person : Screen
{
private string personName_;
public string PersonName
{
get { return personName_; }
set { this.SetProperty(ref personName_, value, nameof(PersonName)); }
}
public Person(string personName)
{
PersonName = personName;
}
private bool isSelected_;
public bool IsSelected
{
get { return isSelected_; }
set { this.SetProperty(ref isSelected_, value, nameof(IsSelected)); }
}
}
View.XAML
<Grid Width="500" Height="500" Background="LightBlue">
<ListBox x:Name="ListOfPeople" SelectionMode="Multiple" Height="300" Width="300" Margin="120,100,80,100">
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding PersonName}" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ListBox>
in that SelectedListOfPeople is not called when the second item is selected in ListBox set to Multiple selections. How can I make sure that this event is raised every time the user makes a selection in ListBox?
One way of doing this would be to break from the convention available in that framework and bind the property manually.
But first you would need to update the property for multiselect in the view model
private ObservableCollection<Person> selectedListOfPeople;
public ObservableCollection<Person> SelectedListOfPeople {
get { return selectedListOfPeople; }
set { this.SetProperty(ref selectedListOfPeople, value, nameof(SelectedListOfPeople)); }
}
private ObservableCollection<Person> listOfPeople;
public ObservableCollection<Person> ListOfPeople {
get { return listOfPeople; }
set { this.SetProperty(ref listOfPeople, value, nameof(ListOfPeople)); }
}
public ShellViewModel() {
ListOfPeople = new ObservableCollection<Person> {
new Person("ABC"),
new Person("DEF"),
new Person("GHI"),
new Person("JKL")
};
SelectedListOfPeople = new ObservableCollection<Person>();
}
And then bind to the desired property in the view's XAML
<ListBox x:Name="ListOfPeople" SelectionMode="Multiple"
Height="300" Width="300" Margin="120,100,80,100"
SelectedItems = "{Bining SelectedListOfPeople}"
>
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding PersonName}" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ListBox>
The convention will bind the items source or the ListBox and the manual binding of the SelectedItems will provided the desired behavior.
So I'm trying to test UI WPF application. I'm using TestStack.White framework for testing. UI has custom control DragDropItemsControl. This control inherits from ItemsControl. So how can I test this control.
<wpf:DragDropItemsControl x:Name="uiTabsMinimizedList"
Margin="0 0 0 5"
VerticalAlignment="Top"
AllowDropOnItem="False"
DragDropTemplate="{StaticResource TemplateForDrag}"
ItemDropped="uiTabsMinimizedList_ItemDropped"
ItemsSource="{Binding ElementName=uiMain,
Path=MinimizedTabs}"
ScrollViewer.HorizontalScrollBarVisibility="Disabled"
ScrollViewer.VerticalScrollBarVisibility="Disabled"
TextBlock.Foreground="{Binding RelativeSource={RelativeSource Mode=FindAncestor,
AncestorType=UserControl},
Path=Foreground}">
<wpf:DragDropItemsControl.ItemTemplate>
<DataTemplate>
<Border >
<TextBlock Cursor="Hand" Text="{Binding Panel.Label}" />
</Border>
</DataTemplate>
</wpf:DragDropItemsControl.ItemTemplate>
</wpf:DragDropItemsControl>
Can we test?
You have to create your own AutomationPeer for your DragDropItemsControl and for your custom control item then you will be able to define the AutomationId as an identifier of the your item object.
public class DragDropItemsControl : ItemsControl
{
protected override AutomationPeer OnCreateAutomationPeer()
{
return new DragDropItemsAutomationPeer(this);
}
}
The custom AutomationPeer class for your control.
public class DragDropItemsControlAutomationPeer : ItemsControlAutomationPeer
{
public DragDropItemsControlAutomationPeer(DragDropItemsControl owner)
: base(owner)
{
}
protected override string GetClassNameCore()
{
return "DragDropItemsControl";
}
protected override ItemAutomationPeer CreateItemAutomationPeer(object item)
{
return new DragDropItemsControlItemAutomationPeer(item, this);
}
}
The custom AutomationPeer class for your control items.
The important part here is the implementation of the method GetAutomationIdCore().
public class DragDropItemsControlItemAutomationPeer : ItemAutomationPeer
{
public DragDropItemsControlItemAutomationPeer(object item, ItemsControlAutomationPeer itemsControlAutomationPeer)
: base(item, itemsControlAutomationPeer)
{
}
protected override string GetClassNameCore()
{
return "DragDropItemsControl_Item";
}
protected override string GetAutomationIdCore()
{
return (base.Item as MyTestItemObject)?.ItemId;
}
protected override AutomationControlType GetAutomationControlTypeCore()
{
return base.GetAutomationControlType();
}
}
For the following xaml code
<local:MyItemsControl x:Name="icTodoList" AutomationProperties.AutomationId="TestItemsControl">
<local:MyItemsControl.ItemTemplate>
<DataTemplate>
<Border >
<TextBlock Cursor="Hand" Text="{Binding Title}" />
</Border>
</DataTemplate>
</local:MyItemsControl.ItemTemplate>
</local:MyItemsControl>
Init in code behind
public MyMainWindow()
{
InitializeComponent();
List<MyTestItemObject> items = new List<MyTestItemObject>();
items.Add(new MyTestItemObject() { Title = "Learning TestStack.White", ItemId="007" });
items.Add(new MyTestItemObject() { Title = "Improve my english", ItemId = "008" });
items.Add(new MyTestItemObject() { Title = "Work it out", ItemId = "009" });
icTodoList.ItemsSource = items;
}
public class MyTestItemObject
{
public string Title { get; set; }
public string ItemId { get; set; }
}
We can see in UIAVerify
Sample code to check the values
// retrieve the custom control
IUIItem theItemsControl = window.Get(SearchCriteria.ByAutomationId("008"));
if (theItemsControl is CustomUIItem)
{
// retrieve the custom control container
IUIItemContainer controlContainer = (theItemsControl as CustomUIItem).AsContainer();
// get the child components
WPFLabel theTextBlock = controlContainer.Get<WPFLabel>(SearchCriteria.Indexed(0));
// get the text value
string textValue = theTextBlock.Text;
}
I have a ListView of Button elements like this:
<ListView ItemsSource="{Binding DummyModelList}" SelectedItem="{Binding SelectedItem}">
<ListViewItem >
<Button Name="test" Grid.Row="0" Grid.Column="10" Grid.ColumnSpan="4" Grid.RowSpan="4" VerticalAlignment="Center" Background="Transparent" Command="{Binding DataContext.TestCommand, RelativeSource={RelativeSource FindAncestor, AncestorType=ListView}}">
<Button.Template>
<ControlTemplate>
<Grid RenderTransformOrigin="0.5,0.5" x:Name="bg">
<Image Source="{Binding DataContext.SlidOnOffImg , RelativeSource={RelativeSource FindAncestor, AncestorType=ListView}}"/>
</Grid>
</ControlTemplate>
</Button.Template>
</Button>
</ListViewItem >
In my ViewModel:
public class MyViewModel:BindableBase
{
private ObservableCollection<Slide> dummyModelList;
public ObservableCollection<Slide> DummyModelList
{
get { return dummyModelList; }
set
{
dummyModelList = value;
OnPropertyChanged(() => DummyModelList);
}
}
public string SlidOnOffImg { get; set; }
private int selectedItem;
public int SelectedItem //this property stores currently selected item from thumbnails list
{
get { return selectedItem; }
set
{
selectedItem = value;
OnPropertyChanged(() => SelectedItem);
}
public CompositeCommand TestCommand { get; set; }
public MyViewModel(IRegionManager regionManager, IEventAggregator eventAggregator) //constructor
{
dummyModelList = new ObservableCollection<ISlide>() { new Slide(), new Slide(), new Slide()};
TestCommand = new CompositeCommand();
TestCommand.RegisterCommand(new DelegateCommand(ChangeImage));
}
private void ChangeImage()
{
if (dummyModelList.ElementAt(selectedItem).SlideExcluded)
dummyModelList.ElementAt(selectedItem).SlideExcluded = false;
else
dummyModelList.ElementAt(selectedItem).SlideExcluded = true;
SlidOnOffImg = dummyModelList.ElementAt(selectedItem).SlideONOFFImgPath;
OnPropertyChanged(() => SlidOnOffImg);
}
}
In my model:
public class Slide : ISlide
{
public bool SlideExcluded { get; set; }
public string SlideONOFFImgPath
{
get
{
if(SlideExcluded)
return "/Assets/Visible_OFF.png";
else
return "/Assets/Visible_ON.png";
}
}
}
My goal is to have button's image to toggle between two image paths on button click. It works, but the problem is that all the buttons in the list change the image path on some button click. I want only the one that is clicked to change the image path.
How to solve this?
You need to be binding to SelectedIndex instead of SelectedItem in your XAML. SelectedIndex holds a reference to the index for the item in the list, SelectedItem holds a reference to the object in the list. Either that, or change your view model to work with the actual object rather than the index.
Say for example I have the following type:
public class Site
{
public string Name { get; set; }
public int SiteId { get; set; }
public bool IsLocal { get; set; }
}
The above type can be assigned to be held in a Propety in a ViewModel like so assuming a corresponding backing field has been created but omitted here ofc:
public Site SelectedSite
{
get { return _selectedSite; }
set
{
_selectedSite = value;
// raise property changed etc
}
}
In my xaml a straight forward binding would be:
<TextBlock x:Name="StatusMessageTextBlock"
Width="Auto"
Height="Auto"
Style="{StaticResource StatusMessageboxTextStyle}"
Text="{Binding MessageToDisplay,
Mode=OneWay,
UpdateSourceTrigger=PropertyChanged}" />
Can you extend a binding by using the dot notation syntax? e.g:
<TextBlock x:Name="StatusMessageTextBlock"
Width="Auto"
Height="Auto"
Style="{StaticResource StatusMessageboxTextStyle}"
**Text="{Binding SelectedSite.Name,**
Mode=OneWay,
UpdateSourceTrigger=PropertyChanged}" />
Seems like a an interesting feature but my gut instinct is a no as my DC is being assigned at RunTime so at DesignTime or CompileTime, I can't see any clues that could make this feature work or not?
Correct me if have misunderstood what a complex object is, I have simplified mine down for the sake of this question.
Of course this is possible. However, WPF needs to know when any property along the path has changed. To that end, you need to implement INotifyPropertyChanged (or other supported mechanisms). In your example, both Site and the VM containing SelectedSite should implement change notification).
Here's how you could implement the functionality you specified in your question:
// simple DTO
public class Site
{
public string Name { get; set; }
public int SiteId { get; set; }
public bool IsLocal { get; set; }
}
// base class for view models
public abstract class ViewModel
{
// see http://kentb.blogspot.co.uk/2009/04/mvvm-infrastructure-viewmodel.html for an example
}
public class SiteViewModel : ViewModel
{
private readonly Site site;
public SiteViewModel(Site site)
{
this.site = site;
}
// this is what your view binds to
public string Name
{
get { return this.site.Name; }
set
{
if (this.site.Name != value)
{
this.site.Name = value;
this.OnPropertyChanged(() => this.Name);
}
}
}
// other properties
}
public class SitesViewModel : ViewModel
{
private readonly ICollection<SiteViewModel> sites;
private SiteViewModel selectedSite;
public SitesViewModel()
{
this.sites = ...;
}
public ICollection<SiteViewModel> Sites
{
get { return this.sites; }
}
public SiteViewModel SelectedSite
{
get { return this.selectedSite; }
set
{
if (this.selectedSite != value)
{
this.selectedSite = value;
this.OnPropertyChanged(() => this.SelectedSite);
}
}
}
}
And your view might look something like this (assuming a DataContext of type SitesViewModel):
<ListBox ItemsSource="{Binding Sites}" SelectedItem="{Binding SelectedSite}"/>
Below is what worked for me:
public Site SelectedSite
{
get { return _selectedSite; }
set
{
_selectedSite = value;
RaisePropertyChanged("SelectedSite");
}
}
In my xaml I was able to do:
<TextBox Name="tbSiteName"
Width="250"
Height="30"
Margin="0"
HorizontalAlignment="Left"
VerticalAlignment="Top"
IsReadOnly="True"
Style="{StaticResource MainTextBoxStyle}"
Text="{Binding SelectedSite.Name,
Mode=OneWay,
UpdateSourceTrigger=PropertyChanged}" />
This allows you to access data members off the Site Type without having to create individual properties that wrap each data member on the Site Type. Then individual controls can bind to each property declared in the VM. In a one to one fashion, this aproach can become rather verbose. The binding extension attached to the Text property of the TextBox control shown above, shows that we are not binding to a simple straight forward property but actually to a custom type. Potentially removing the need to create more public properties.
I have one main outstanding issue, I know now how to databind to lists and individual items, but there is one more problem I have with this, I need to bind a listbox to some properties that are in a Class.
For Example I have two Properties that are bound in some XAML in a class called Display:
Public Property ShowEventStart() As Visibility
Public Property ShowEventEnd() As Visibility
I can use these in my XAML but I want them to be in a ListBox/Drop-down List, how can I have my properties show in this list and be able to change their values, does it have to be a List to be in a List?
I just want to be able to modify these properties from a Drop-down list to toggle the Visibility of the ShowEventStart and ShowEventEnd Property Values using the Checkboxes in the Drop-down List.
Plus this must be a Silverlight 3.0 solution, I cannot figure out how to have something that can be bound in the XAML which is not a list and then bound it as a list to modify these items!
I just need a list of Checkboxes which alter the values of the Class Properties such as ShowEventStart and ShowEventEnd, there are other properties but this will be a start.
You can create a PropertyWrapper class and in you window code behind expose a property that returns a List<PropertyWrapper> and bind your ListBox.ItemsSource to it.
public class PropertyWrapper
{
private readonly object target;
private readonly PropertyInfo property;
public PropertyWrapper(object target, PropertyInfo property)
{
this.target = target;
this.property = property;
}
public bool Value
{
get
{
return (bool) property.GetValue(target, null);
}
set
{
property.SetValue(target, value, null);
}
}
public PropertyInfo Property
{
get
{
return this.property;
}
}
}
your window code behind:
public partial class Window1 : Window, INotifyPropertyChanged
{
public Window1()
{
InitializeComponent();
properties = new List<PropertyWrapper>
{
new PropertyWrapper(this, typeof(Window1).GetProperty("A")),
new PropertyWrapper(this, typeof(Window1).GetProperty("B")),
};
this.DataContext = this;
}
private List<PropertyWrapper> properties;
public List<PropertyWrapper> Properties
{
get { return properties; }
}
private bool a;
private bool b = true;
public bool A
{
get
{
return a;
}
set
{
if (value != a)
{
a = value;
NotifyPropertyChange("A");
}
}
}
public bool B
{
get
{
return b;
}
set
{
if (value != b)
{
b = value;
NotifyPropertyChange("B");
}
}
}
protected void NotifyPropertyChange(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged.Invoke(
this, new PropertyChangedEventArgs(propertyName));
}
}
public event PropertyChangedEventHandler PropertyChanged;
}
your window markup:
<ListBox ItemsSource="{Binding Path=Properties}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=Property.Name}"/>
<CheckBox IsChecked="{Binding Path=Value}" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Hope this helps
I tried to mock up something similar. See how this works for you and let me know if I misunderstood the question.
From MainPage.xaml:
<StackPanel Orientation="Horizontal">
<ListBox SelectedItem="{Binding ShowControls, Mode=TwoWay}" x:Name="VisibilityList"/>
<Button Content="Test" Visibility="{Binding ShowControls}"/>
<CheckBox Content="Test 2" Visibility="{Binding ShowControls}"/>
</StackPanel>
The code behind MainPage.xaml.cs:
public partial class MainPage : UserControl
{
VisibilityData visibilityData = new VisibilityData();
public MainPage()
{
InitializeComponent();
VisibilityList.Items.Add(Visibility.Visible);
VisibilityList.Items.Add(Visibility.Collapsed);
this.DataContext = visibilityData;
}
}
And the data class:
public class VisibilityData : INotifyPropertyChanged
{
private Visibility showControls = Visibility.Visible;
public Visibility ShowControls
{
get { return showControls; }
set
{
showControls = value;
OnPropertyChanged("ShowControls");
}
}
private void OnPropertyChanged(string p)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(p));
}
public event PropertyChangedEventHandler PropertyChanged;
}
When you run that code you should get a ListBox with the options Visible and Collapsed and when you choose an option you should see the visibility of the button and checkbox is changed to reflect your choice. Let me know if that's not what you were looking for.
After thinking about this the solution occured to me, which is to construct the List in XAML then using a Converter on the Checkboxes to convert their Boolean IsChecked to the Property Visibility Property in the Class.
You can create a list such as:
<ComboBox Canvas.Left="6" Canvas.Top="69" Width="274" Height="25" Name="Display">
<StackPanel Orientation="Horizontal">
<CheckBox IsChecked="{Binding Path=Display.EventStart,Mode=TwoWay,Converter={StaticResource VisibilityConverter}}"/>
<TextBlock Text="Event Start"/>
</StackPanel>
<StackPanel Orientation="Horizontal">
<CheckBox IsChecked="{Binding Path=Display.EventEnd,Mode=TwoWay,Converter={StaticResource VisibilityConverter}}"/>
<TextBlock Text="Event End"/>
</StackPanel>
</ComboBox>
I can then Bind to the Two Properties I want (this example from the actual application).