I have a conditional style using a StyleSelector, so that it changes the color of the playing song to green when the program loads. However, when the songIndex static variable is changed, I don't know how to make it update. I tried using the INotifyPropertyChanged interface, but am not sure how to use it properly or what I am supposed to bind to it. Here is my code....
public class HighlightStyleSelector : StyleSelector, INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected override Style SelectStyleCore(object item, DependencyObject container)
{
//List<myMediaInterface> mediaList = new List<myMediaInterface>();
if (item == MainPage.mediaList[MainPage.songIndex])
{
Style style = new Style(typeof(ListViewItem));
style.Setters.Add(new Setter(ListViewItem.BackgroundProperty, new SolidColorBrush(Colors.LightGreen)));
return style;
}
else
{
var style = Application.Current.Resources["ListViewItemStyle1"] as Style;
return null;
}
}
public int songIndex
{
get { return MainPage.songIndex; }
set
{
songIndex = MainPage.songIndex;
OnPropertyChanged(songIndex.ToString());
}
}
protected void OnPropertyChanged(String propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
Xaml:
<ListView x:Name="songlistView" SelectionMode="Extended" DoubleTapped="songlistView_DoubleTapped" HorizontalContentAlignment="Stretch" BorderThickness="1" BorderBrush="#FF616161" ScrollViewer.HorizontalScrollBarVisibility="Auto" ScrollViewer.HorizontalScrollMode="Enabled" ManipulationMode="None" UseLayoutRounding="False" VerticalContentAlignment="Stretch" Margin="2,150,0,558" Tapped="songlistView_Tapped" FontSize="14" ItemContainerStyleSelector="{StaticResource HighlightStyleSelector}" ItemsSource="{Binding MainPage.mediaList}">
Here is the code for the custom listview
namespace HelloWorld
{
public class MyListView : Control
{
public int highlightedItem;
public MyListView()
{
this.DefaultStyleKey = typeof(MyListView);
}
}
}
If I use get; and set; for hightlighted item doesn't work either. Still says the member highlightedItem is not recognized or is not accessible
Edited 5/25
this is now in MainPage.xaml.cs
public int songIndex
{
get
{
return songIndex;
}
set
{
songIndex = value;
OnPropertyChanged("songIndex");
}
}
^^ not sure if this should go with my field declarations?
public void OnPropertyChanged(String propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
Here is my code from MainPage.xaml
<ListView x:Name="songlistView" SelectedIndex="{Binding songIndex}" SelectionMode="Extended" DoubleTapped="songlistView_DoubleTapped" HorizontalContentAlignment="Stretch" BorderThickness="1" BorderBrush="#FF616161" ScrollViewer.HorizontalScrollBarVisibility="Auto" ScrollViewer.HorizontalScrollMode="Enabled" ManipulationMode="None" UseLayoutRounding="False" VerticalContentAlignment="Stretch" Margin="2,150,0,558" Tapped="songlistView_Tapped" FontSize="14" ItemsSource="{Binding MainPage.mediaList}"><!--ItemContainerStyleSelector="{StaticResource HighlightStyleSelector}"-->
<ListView.ItemsPanel>
<ItemsPanelTemplate>
<VirtualizingStackPanel/>
</ItemsPanelTemplate>
</ListView.ItemsPanel>
</ListView>
Here is my code 5/26
I'm trying to create a dependencyproperty called highlightedIndex that is identical to selectedIndex, except that it is separate.
public class MyListView : ListView
{
public int highlightedIndex
{
get { return (int)GetValue(HighlightedProperty); }
set
{
SetValue(HighlightedProperty, value);
}
}
public static readonly DependencyProperty HighlightedProperty = DependencyProperty.Register("HighlightedProperty", typeof(int), typeof(MyListView), new PropertyMetadata(0));
}
namespace HelloWorld
{
public class HighlightStyleSelector : StyleSelector
{
protected override Style SelectStyleCore(object item, DependencyObject container)
{
if (item == MainPage.mediaList[MainPage.songIndex])
{
var style = Application.Current.Resources["ListViewItemHighlighted"] as Style;
Setter setter = new Setter(ListViewItem.BackgroundProperty, new SolidColorBrush(Colors.LightGreen));
//Style style = new Style(typeof(ListViewItem));
style.Setters.Add(setter);
return style;
}
else
{
var style = Application.Current.Resources["ListViewItemStyle1"] as Style;
return style;
}
}
}
}
I'm a bit confused because of static properties on MainPage you seem to be assigning songIndex to and binding mediaList to. It would be helpful to see that code as well.
Still, you need to fix your property (assuming OnPropertyChanged is implemented correctly):
public int songIndex
{
get { return MainPage.songIndex; }
set
{
// set the assigned value to property backing field
MainPage.songIndex = value;
// you need to notify with the name of the property as the argument
OnPropertyChanged("songIndex");
}
}
Then you can bind to this property like any other with the only difference that the control will be notified when its value changes:
<ListView SelectedIndex="{Binding songIndex}" />
public static readonly DependencyProperty HighlightedProperty = DependencyProperty.Register("highlightedIndex", typeof(int), typeof(MyListView), new PropertyMetadata(null, propertyChanged));
private static void propertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
int newValue = (int)e.NewValue;
ListView lv = (ListView)d;
foreach (ListViewItem lvi in lv.Items)
{
if (lv.Items.IndexOf(lvi) == newValue)
{
lvi.Background = new SolidColorBrush(Colors.LightGreen);
}
else
{
lvi.Background = new SolidColorBrush();
}
}
}
Didn't need the styleselector or any binding
Related
I'm pretty new to programming with WPF and C# and I have a question regarding the possibility to automatically check all the CheckBoxes in a Listbox. I'm developing a plugin for Autodesk Revit and, after having listed all the names of the rooms in a list box, I want to check them all using the button "Check All"
I've read the thread at this page but still, I'm not able to make it work. May someone help me with my code?
Here is what I've done:
XAML:
<ListBox x:Name='roomlist'
SelectionMode='Multiple'>
<ListBox.ItemTemplate>
<DataTemplate>
<CheckBox IsChecked='{Binding IsChecked}'
Content="{Binding}" />
</DataTemplate>
</ListBox.ItemTemplate>
<ListBox.InputBindings>
<KeyBinding Command="ApplicationCommands.SelectAll"
Modifiers="Ctrl"
Key="A" />
</ListBox.InputBindings>
<ListBox.CommandBindings>
<CommandBinding Command="ApplicationCommands.SelectAll" />
</ListBox.CommandBindings>
</ListBox>
C#
public partial class RoomsDistance_Form : Window
{
UIDocument _uidoc;
Document _doc;
public RoomsDistance_Form(Document doc, UIDocument uidoc)
{
InitializeComponent();
FilteredElementCollector collector = new FilteredElementCollector(doc)
.WhereElementIsNotElementType()
.OfCategory(BuiltInCategory.OST_Rooms);
List<String> myRooms = new List<String>();
foreach (var c in collector)
{
myRooms.Add(c.Name);
}
myRooms.Sort();
roomlist.ItemsSource = myRooms;
}
private void checkAllBtn_Click(object sender, RoutedEventArgs e)
{
foreach (CheckBox item in roomlist.Items.OfType<CheckBox>())
{
item.IsChecked = true;
}
}
public class Authority : INotifyPropertyChanged
{
private bool isChecked;
public bool IsChecked
{
get { return isChecked; }
set
{
isChecked = value;
NotifyPropertyChanged();
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(string propertyName = "")
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
}
Thank you very much for your help!
In the thread you are linking to, they are setting the "IsChecked" on the data object (Authority), not the CheckBox control itself.
foreach (var a in authorityList)
{
a.IsChecked = true;
}
You have a binding to IsChecked that will update the Checkbox control when NotifyPropertyChanged() is called.
After having lost my mind in the effort i solved my problem by avoiding the Listbox.. I simply added single CheckBoxes in the StackPanel.
XAML:
<ScrollViewer Margin='10,45,10,100'
BorderThickness='1'>
<StackPanel x:Name='stack'
Grid.Column='0'></StackPanel>
</ScrollViewer>
C#:
foreach (var x in myRooms)
{
CheckBox chk = new CheckBox();
chk.Content = x;
stack.Children.Add(chk);
}
Not what i was looking for but now it works and that's the point.
Thank you for your help!
I usually use CheckBoxList in the following way:
In xaml:
<ListBox ItemsSource="{Binding ListBoxItems, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"> //+some dimensional properties
<ListBox.ItemTemplate>
<DataTemplate>
<CheckBox Content="{Binding Name}" IsChecked="{Binding IsSelected, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
In xaml.cs:
public partial class MyWindow : Window
{
public ViewModel ViewModel {get; set; }
public MyWindow(ViewModel viewModel)
{
//keep all the mess in ViewModel, this way your xaml.cs will not end up with 1k lines
ViewModel = viewModel;
DataContext = ViewModel;
InitializeComponent();
}
void BtnClick_SelectAll(object sender, RoutedEventArgs e)
{
ViewModel.CheckAll();
}
}
ViewModel preparation:
public class ViewModel
{
public List<ListBoxItem> ListBoxItems { get; set; }
//InitializeViewModel()...
//UpdateViewModel()...
//other things....
public void CheckAll()
{
foreach (var item in ListBoxItems)
{
item.IsSelected = true;
}
}
public class ListBoxItem : INotifyPropertyChanged
{
public string Name { get; set; }
private bool _isSelected;
public bool IsSelected
{
get { return _isSelected; }
set
{
if (_isSelected != value)
{
_isSelected = value;
OnPropertyChanged(nameof(IsSelected));
}
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string propertyName)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
I've got ComboBox and ListBox of CheckBoxes. Depending on SelectedItem of ComboBox ItemSource of ListBox must change. I made a sample to make thing easier. Here is the code:
ViewModel
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
namespace Test
{
class Data
{
public long Id;
public object Value;
public override string ToString()
{
return Value.ToString();
}
}
class CheckedData: INotifyPropertyChanged
{
private Data myData;
public Data MyData
{
get { return myData; }
set
{
if (myData == value)
return;
myData = value;
RaisePropertyChanged(nameof(MyData));
}
}
private bool isChecked;
public bool IsChecked
{
get { return isChecked; }
set
{
isChecked = value;
RaisePropertyChanged(nameof(IsChecked));
}
}
public event PropertyChangedEventHandler PropertyChanged;
protected void RaisePropertyChanged(string propertyName)
{
var handler = PropertyChanged;
handler?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
class BindingObject: INotifyPropertyChanged
{
private ObservableCollection<Data> dataList = new ObservableCollection<Data>();
public ObservableCollection<Data> DataList
{
get { return dataList; }
set
{
dataList = value;
RaisePropertyChanged(nameof(DataList));
}
}
private Data selectedItem;
public Data SelectedItem
{
get { return selectedItem; }
set
{
if (value == selectedItem)
return;
selectedItem = value;
}
}
public event PropertyChangedEventHandler PropertyChanged;
protected void RaisePropertyChanged(string propertyName)
{
var handler = PropertyChanged;
handler?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
class ViewModel: INotifyPropertyChanged
{
public ViewModel()
{
var tmp = new Data() {Id = 1, Value = "Cat"};
Obj.DataList.Add(tmp);
Obj.SelectedItem = tmp;
Obj.DataList.Add(new Data() {Id = 2, Value = "Dog"});
Mapping[1] = new ObservableCollection<CheckedData>()
{
new CheckedData() {IsChecked = true, MyData = new Data() {Id = 1, Value = "Maine coon"}},
new CheckedData() {IsChecked = true, MyData = new Data() {Id = 2, Value = "Siberian"}}
};
}
private BindingObject obj = new BindingObject();
public BindingObject Obj
{
get { return obj; }
set
{
if (obj == value)
return;
obj = value;
RaisePropertyChanged(nameof(Obj));
}
}
private Dictionary<long, ObservableCollection<CheckedData>> mapping = new Dictionary<long, ObservableCollection<CheckedData>>();
public Dictionary<long, ObservableCollection<CheckedData>> Mapping
{
get { return mapping; }
set
{
if (mapping == value)
return;
mapping = value;
RaisePropertyChanged(nameof(Mapping));
}
}
public event PropertyChangedEventHandler PropertyChanged;
protected void RaisePropertyChanged(string propertyName)
{
var handler = PropertyChanged;
handler?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
}
View
<ComboBox x:Name="comboBox" ItemsSource="{Binding Path=Obj.DataList}" SelectedItem="{Binding Path=Obj.SelectedItem, Mode=TwoWay}"/>
<ListBox x:Name="listBox" Height="100" ItemsSource="{Binding Path=Mapping[Obj.SelectedItem.Id]}">
<ListBox.ItemTemplate>
<DataTemplate>
<CheckBox IsChecked="{Binding IsChecked, Mode=TwoWay}" Content="{Binding Path=MyData.Value}" Margin="0,5,5,0"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
That is what I thought should work. ComboBox is okay, but ListBox ItemSource binding doesn't work. Only if I bind directly to list like this:
ViewModel
private ObservableCollection<CheckedData> test = new ObservableCollection<CheckedData>()
{
new CheckedData() {IsChecked = true, MyData = new Data() {Id = 1, Value = "Maine coon"}},
new CheckedData() {IsChecked = false, MyData = new Data() {Id = 2, Value = "Siberian"}}
};
public ObservableCollection<CheckedData> Test
{
get { return test; }
set
{
test = value;
RaisePropertyChanged(nameof(Test));
}
}
View
<ListBox x:Name="listBox" Height="100" ItemsSource="{Binding Path=Test}">
<ListBox.ItemTemplate>
<DataTemplate>
<CheckBox IsChecked="{Binding IsChecked, Mode=TwoWay}" Content="{Binding Path=MyData.Value}" Margin="0,5,5,0"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Everything starts working.. Except Content binding, because I can't go deeper than 1 level of property path. So I have to override ToString() method in Data.
What should I fix to make everything work? Am I able to bind ItemSource like this? Why can't I go deeper than 1 lvl property binding in CheckBox?
Am I able to bind ItemSource like this?
No, this kind of bindings are not supported in XAML:
Binding Path=Mapping[Obj.SelectedItem.Id].
You must replace Obj.SelectedItem.Id with a constant key value like 1 or bind to some other property that returns the collection of items.
Everything starts working.. Except Content binding
You can only bind to public properties so Value must be a property and not a field:
class Data
{
public long Id { get; set; }
public object Value { get; set; }
}
You can achive this easy with:
public ObservableCollection<CheckedData> SelectedData
{
get
{
return Mapping[Obj.SelectedItem.Id];
}
}
And into
public Data SelectedItem
{
get { return selectedItem; }
set
{
if (value == selectedItem)
return;
selectedItem = value;
RaisePropertyChanged(nameof(SelectedData)); // add this.
}
}
Now, in XAML, you can easy:
<ListBox x:Name="listBox" Height="100" ItemsSource="{Binding Path=Obj.SelectedData}">
I have two different objects that are pointing at each other. The first object represents a division in a company. That object has two collection: Employees, which is all the employees working in the division and Project, which is all the special projects that are in progress within that division. So the first object looks like this:
public class Division : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged = delegate { };
ObservableCollection<Employee> _employees;
ObservableCollection<Project> _projects;
public Division()
{
Employees = new ObservableCollection<Employee>();
Projects = new ObservableCollection<Project>();
}
public ObservableCollection<Employee> Employees
{
get { return _employees; }
set
{
if (_employees != value)
{
_employees = value;
PropertyChanged(this, new PropertyChangedEventArgs("Employees"));
}
}
}
public ObservableCollection<Project> Projects
{
get { return _projects; }
set
{
if (_projects != value)
{
_projects = value;
PropertyChanged(this, new PropertyChangedEventArgs("Projects"));
}
}
}
public void AddNewProject()
{
this.Projects.Add(new Project(this));
}
}
Notice that when adding a new project to the division, I pass a reference to the division into that project, which looks like this:
public class Project : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged = delegate { };
string _projectName;
DateTime _deadline = DateTime.Now;
Division _division;
ObservableCollection<Employee> _members;
public Project()
{
Members = new ObservableCollection<Employee>();
}
public Project(Division div)
{
Members = new ObservableCollection<Employee>();
Division = div;
}
public string ProjectName
{
get { return _projectName; }
set
{
if (_projectName != value)
{
_projectName = value;
PropertyChanged(this, new PropertyChangedEventArgs("ProjectName"));
}
}
}
public DateTime Deadline
{
get { return _deadline; }
set
{
if (_deadline != value)
{
_deadline = value;
PropertyChanged(this, new PropertyChangedEventArgs("Deadline"));
}
}
}
public Division Division
{
get { return _division; }
set
{
if (_division != value)
{
if (_division != null)
{
_division.Employees.CollectionChanged -= members_CollectionChanged;
}
_division = value;
if (_division != null)
{
_division.Employees.CollectionChanged += members_CollectionChanged;
}
PropertyChanged(this, new PropertyChangedEventArgs("Division"));
}
}
}
public ObservableCollection<Employee> Members
{
get { return _members; }
set
{
if (_members != value)
{
if (_members != null)
{
_members.CollectionChanged -= members_CollectionChanged;
}
_members = value;
if (_members != null)
{
_members.CollectionChanged += members_CollectionChanged;
}
PropertyChanged(this, new PropertyChangedEventArgs("Members"));
}
}
}
public ObservableCollection<Employee> AvailableEmployees
{
get
{
if (Division != null){
IEnumerable<Employee> availables =
from s in Division.Employees
where !Members.Contains(s)
select s;
return new ObservableCollection<Employee>(availables);
}
return new ObservableCollection<Employee>();
}
}
void members_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
{
PropertyChanged(this, new PropertyChangedEventArgs("AvailableEmployees"));
}
}
The reason I'm doing it like this is, that the project could have any type of team working on it, but only from within the division. So, when building a dashboard for the division, the manager could select any of the employees to that project but without putting in an employee that is already assigned to it. So, the AvailableEmployees property in the project object always keeps track of who is not already assigned to that project.
The problem I'm having is how to translate this into a UI. The experiment I've done so far looks like this:
<UserControl x:Class="Test.Views.TestView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
xmlns:local="clr-namespace:Test.Views"
d:DesignHeight="300" d:DesignWidth="300">
<StackPanel>
<ListBox ItemsSource="{Binding Div.Projects}">
<ListBox.ItemTemplate>
<DataTemplate>
<Border Background="Transparent"
BorderThickness="0, 0, 0, 2"
BorderBrush="Black"
Margin="0, 0, 0, 5"
Padding="0, 0, 0, 5">
<StackPanel>
<TextBox Text="{Binding ProjectName}"/>
<ListBox ItemsSource="{Binding Members}">
<ListBox.ItemTemplate>
<DataTemplate>
<ComboBox ItemsSource="{Binding RelativeSource={RelativeSource AncestorType=local:TestView}, Path=DataContext.AvailableEmployees}"
DisplayMemberPath="FirstName"
Text="{Binding FirstName}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
<Button Content="Add Employee to Project"
Command="{Binding RelativeSource={RelativeSource AncestorType=local:TestView}, Path=DataContext.AddEmployeeToProject}"
CommandParameter="{Binding}"/>
</StackPanel>
</Border>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
<Button Content="Add New Project"
Command="{Binding AddNewProject}" />
</StackPanel>
The view model associated with this view is as follows:
public class TestViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged = delegate { };
private Division _div;
public TestViewModel(Division div)
{
Div = div;
AddNewProject = new DelegateCommand(OnAddNewProject);
AddEmployeeToProject = new DelegateCommand<Project>(OnAddEmployeeToProject);
}
public DelegateCommand AddNewProject { get; set; }
public DelegateCommand<Project> AddEmployeeToProject { get; set; }
public Division Div
{
get { return _div; }
set
{
if (_div != value)
{
_div = value;
PropertyChanged(this, new PropertyChangedEventArgs("Div"));
}
}
}
private void OnAddNewProject()
{
Div.AddNewProject();
}
private void OnAddEmployeeToProject(Project proj)
{
var availables = proj.AvailableEmployees;
if (availables.Count > 0)
{
proj.Members.Add(availables[0]);
}
}
}
However, I cannot get the combobox for each employee in each project to work. It seems like the selected item/value is bound to the itemssource, and each time the combobox turns out blank. I've tried to do this also with SelectedValue and SelectedItem properties for the combobox, but none worked.
How do I get these two separated. Is there anything else I'm missing here?
OK. After so many experiments the best solution I came up with was to create my own user control that is composed of both a button and a combobox that imitate the behavior I was expecting of the combobox on it own.
First, I had a really stupid mistake in the model where both lists of members Project and Division contain the same instances of Employee, which makes the AvailableEmployees property buggy. What I really needed to do is to create a list of copies of employees in the Project instead of just references.
In any case, I created a new user control and called it DynamicSourceComboBox. The XAML of this control looks like this:
<Grid>
<Button x:Name="selected"
Content="{Binding RelativeSource={RelativeSource AncestorType=local:DynamicSourceComboBox}, Path=SelectedValue}"
Click="selected_Click"/>
<ComboBox x:Name="selections"
ItemsSource="{Binding RelativeSource={RelativeSource AncestorType=local:DynamicSourceComboBox}, Path=ItemsSource}"
DisplayMemberPath="{Binding RelativeSource={RelativeSource AncestorType=local:DynamicSourceComboBox}, Path=DisplayMemberPath}"
Visibility="Collapsed"
SelectionChanged="selections_SelectionChanged"
MouseLeave="selections_MouseLeave"/>
</Grid>
I have here a few bindings from the button and the combobox to properties in my user control. These are actually dependency properties. The code-behind of my user control looks like this:
public partial class DynamicSourceComboBox : UserControl
{
public DynamicSourceComboBox()
{
InitializeComponent();
}
public object SelectedValue
{
get { return (object)GetValue(SelectedValueProperty); }
set { SetValue(SelectedValueProperty, value); }
}
public static readonly DependencyProperty SelectedValueProperty =
DependencyProperty.Register("SelectedValue", typeof(object), typeof(DynamicSourceComboBox), new PropertyMetadata(null));
public IEnumerable ItemsSource
{
get { return (IEnumerable)GetValue(ItemsSourceProperty); }
set { SetValue(ItemsSourceProperty, value); }
}
public static readonly DependencyProperty ItemsSourceProperty =
ComboBox.ItemsSourceProperty.AddOwner(typeof(DynamicSourceComboBox));
public string DisplayMemberPath
{
get { return (string)GetValue(DisplayMemberPathProperty); }
set { SetValue(DisplayMemberPathProperty, value); }
}
public static readonly DependencyProperty DisplayMemberPathProperty =
ComboBox.DisplayMemberPathProperty.AddOwner(typeof(DynamicSourceComboBox));
private void selected_Click(object sender, RoutedEventArgs e)
{
selected.Visibility = Visibility.Hidden;
selections.Visibility = Visibility.Visible;
selections.IsDropDownOpen = true;
}
private void selections_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
selections.Visibility = Visibility.Collapsed;
selected.Visibility = Visibility.Visible;
selections.IsDropDownOpen = false;
if (e.AddedItems.Count == 1)
{
var item = e.AddedItems[0];
Type itemType = item.GetType();
var itemTypeProps = itemType.GetProperties();
var realValue = (from prop in itemTypeProps
where prop.Name == DisplayMemberPath
select prop.GetValue(selections.SelectedValue)).First();
SelectedValue = realValue;
}
}
private void selections_MouseLeave(object sender, MouseEventArgs e)
{
selections.Visibility = Visibility.Collapsed;
selected.Visibility = Visibility.Visible;
selections.IsDropDownOpen = false;
}
}
These dependency properties imitate the properties with similar names in ComboBox but they are hooked up to the internal combobox and the button in a way that makes them behave together as a single complex combobox.
The Click event in the button hides it and present the combobox to make the effect of just a box that is opening. Then I have a SelectionChanged event in the combobox firing to update all the needed information and a MouseLeave event just in case the user doesn't make any real selection change.
When I need to use the new user control, I set it up like this:
<local:DynamicSourceComboBox ItemsSource="{Binding RelativeSource={RelativeSource AncestorLevel=1, AncestorType=ListBox}, Path=DataContext.AvailableEmployees}"
DisplayMemberPath="FirstName"
SelectedValue="{Binding FirstName, Mode=TwoWay}"/>
Of course, for all of it to work, I have to make a lot of hookups with PropertyChanged events in the models, so the Projects instance will know to raise a PropertyChanged event for AvailableEmployees any time a change is made, but this is not really the concern of this user control itself.
This is a pretty clunky solution, with a lot of extra code that is a bit hard to follow, but it's really the best (actually only) solution I could have come up with to the problem I had.
I know I should use the MVVM pattern but I'm trying to get step by step closer to it. So here is my Listbox:
<ListBox x:Name="BoardList" ItemsSource="{Binding notes}" >
<ListBox.ItemTemplate>
<DataTemplate>
<Grid>
<StackPanel Orientation="Horizontal" HorizontalAlignment="Right">
<TextBox IsReadOnly="True" ScrollViewer.VerticalScrollBarVisibility="Visible" Text="{Binding text}" TextWrapping="Wrap" Foreground="DarkBlue"></TextBox>
<AppBarButton Visibility="{Binding visibility}" Icon="Globe" Click="OpenInBrowser" x:Name="Link"></AppBarButton>
<AppBarButton Icon="Copy" Click="Copy"></AppBarButton>
<AppBarButton Icon="Delete" Click="Delete"></AppBarButton>
</StackPanel>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
In the Mainpage.xaml.cs I declare the following:
ObservableCollection<BoardNote> notes = new ObservableCollection<BoardNote>();
So if I understood this right I don't need to care about the "INotifyCollectionChanged" stuff because I'm using an observablecollection?
So I got for example a textbox like this:
<Textbox x:Name="UserInputNote" Placeholdertext="Type in a text for your note"></Textbox>
And a button to Add the new note to the ObservableCollection and the click event is just like this:
notes.Add(new BoardNote(UserInputNote.Text));
So now the UI should update every time the user clicks the button to save a new note. But nothing happens. What did I do wrong?
If you need it here is the BoardNote class:
class BoardNote
{
public string text
{
get; set;
}
public BoardNote(string text)
{
this.text = text;
}
public Visibility visibility
{
get
{
if (text.StartsWith("http"))
return Visibility.Visible;
else
return Visibility.Collapsed;
}
}
}
You need to implement INotifyPropertyChanged. Here's one way of doing it.
Create this NotificationObject class.
public class NotificationObject : INotifyPropertyChanged
{
protected void RaisePropertyChanged<T>(Expression<Func<T>> action)
{
var propertyName = GetPropertyName(action);
RaisePropertyChanged(propertyName);
}
private static string GetPropertyName<T>(Expression<Func<T>> action)
{
var expression = (MemberExpression)action.Body;
var propertyName = expression.Member.Name;
return propertyName;
}
private void RaisePropertyChanged(string propertyName)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
public event PropertyChangedEventHandler PropertyChanged;
}
Then your BoardNote class will inherit it this way:
class BoardNote : NotificationObject
{
private string _text
public string Text
{
get {return _text;}
set
{
if(_text == value) return;
_text = value;
RaisePropertyChanged(() => Text);
}
}
public BoardNote(string text)
{
this.text = text;
}
public Visibility visibility
{
get
{
if (text.StartsWith("http"))
return Visibility.Visible;
else
return Visibility.Collapsed;
}
}
}
I am unable figure out why the databinding is not working as expected:
I created a Listbox and set its ItemSource to my observable collection
I used this.DataContext = this
I Initialized my public Observable Collection
I filled it with objects that implement INotifyPropertyChanged
Yet, the databinding, still does not work. My Listbox:
<ListBox Height="425" ItemsSource="{Binding headers}">
<ListBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Path=HeaderInfo}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
The code behind:
public partial class cornet_controls : PhoneApplicationPage
{
public ObservableCollection<headerInfo> headers;
public cornet_controls()
{
InitializeComponent();
this.DataContext = this;
headers = new ObservableCollection<headerInfo>();
for (int x = 0; x < 100; x++)
headers.Add((new headerInfo() { HeaderInfo = x.ToString() }));
}
}
My custom class implementing INotifyPropertyChanged:
public class headerInfo : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
public headerInfo()
{}
private String _HeaderInfo;
public String HeaderInfo
{
get { return _HeaderInfo; }
set { _HeaderInfo = value; NotifyPropertyChanged("HeaderInfo"); }
}
private void NotifyPropertyChanged(String propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
You cannot bind to a NonProperty:
<ListBox Height="425" ItemsSource="{Binding headers}">
public ObservableCollection<headerInfo> headers;
you need to bind to a Property like:
public ObservableCollection<headerInfo> headers { get; set; }