I'm currently in the process of implementing a menu navigation system for a group project. We're using Caliburn.Micro and the MVVM pattern.
The menu is located in the ShellView.xaml and is based on a List<NavigationMenuItem> that has been filtered using the Role property.
public class NavigationMenuItem
{
public IScreen ViewModel { get; set; }
public string IconPath { get; set; }
public string Role { get; set; }
public NavigationMenuItem(IScreen viewModel, string iconPath, string role)
{
ViewModel = viewModel;
IconPath = iconPath;
Role = role;
}
}
The menu is displaying just fine, but now I want to pass the ViewModel-property to a method in the ShellViewModel.cs, such that I can activate a view change. This is how the ShellView.xaml looks so far:
<Window
x:Class="P3GG.Views.ShellView"
xmlns:cal="http://www.caliburnproject.org"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:P3GG.Views"
xmlns:models="clr-namespace:P3GG.Models"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:templates="clr-namespace:P3GG.Templates"
xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
Title="Title"
Width="800"
Height="600"
WindowStartupLocation="CenterScreen"
mc:Ignorable="d">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="auto" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<ListBox Visibility="{Binding SidebarIsVisible, Converter={StaticResource BooleanToVisibilityConverter}, FallbackValue=Collapsed}"
Grid.Column="0"
Background="#333333"
x:Name="NavigationMenu">
<ListBox.ItemTemplate>
<DataTemplate DataType="models:NavigationMenuItem">
<Button cal:Message.Attach="Handle( <!-- pass content of NavigationMenuItem.ViewModel --> )" Style="{StaticResource BtnSidebar}">
<Image Margin="20" Source="{Binding IconPath}"/>
</Button>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
<ContentControl Grid.Column="1" x:Name="ActiveItem"/>
</Grid>
</Window>
The ShellViewModel.cs currently contains two Handle methods:
public void Handle(Screen screen)
public void Handle(User user)
How do I pass the ViewModel property of a given NavigationMenu to the Handle(Screen) method?
EDIT
Added Handle method per request
public void Handle(Screen screen)
{
if (screen is LoginViewModel)
{
SidebarIsVisible = false;
NotifyOfPropertyChange(() => SidebarIsVisible);
}
else
{
SidebarIsVisible = true;
NotifyOfPropertyChange(() => SidebarIsVisible);
}
ActivateItem(screen);
}
Maybe you can try something like this, as explained here:
<Button cal:Message.Attach="[Event Click] = [Action Handle($dataContext)]" Style="{StaticResource BtnSidebar}">
<Image Margin="20" Source="{Binding IconPath}"/>
</Button>
This will pass the full view model (DataContext) to your handler.
To pass a specific property of your view model, use the long syntax as indicated here:
<Button Style="{StaticResource BtnSidebar}">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Click">
<cal:ActionMessage MethodName="Handle">
<cal:Parameter Value="{Binding ViewModel}" />
</cal:ActionMessage>
</i:EventTrigger>
</i:Interaction.Triggers>
<Image Margin="20" Source="{Binding IconPath}"/>
</Button>
with i defined as
xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
You could also change the DataContext property of the Button to the property of interest, like:
<Button DataContext="{Binding ViewModel}" cal:Message.Attach="[Event Click] = [Action Handle($dataContext)]" Style="{StaticResource BtnSidebar}">
<Image Margin="20" Source="{Binding IconPath}"/>
</Button>
so only the correct property gets passed to your hendler, but this feels like a hack.
On click, this will hand-over the DataContext of the Button as parameter of your Handle method, which should be a NavigationMenuItem.
Related
I am working on my first project with WPF and as practice, have created an application that has a menu bar with two buttons on the side which are used to change the display two different views on the grid to its right. I am using the MVVM pattern. Using the ICommand interface, I am able to change the view in the grid using usercontrols for the two views from the menu bar buttons. The application is as follows:
The menu bar has buttons named View 1 and View 2, clicking any of them will open up the relevant view in the usercontrol. At startup a "defaultview" is displayed. The default view has a button which can also be used to move to View 1. Below is what I am stuck at:
I have a button in View 1 to change the display to View 2 (it calls the same command I made in the App View Model but even though it changes the variable value to which the sidegrid is bound too, the view displayed doesnt change).
I want to pass data (tried with First Name) from View 1 to View 2 but I cant get binding to work.
Can someone guide me or link me to examples or material that discuss this?
App View Model
using DataBindingAndViewsTestProject.Views;
using Hotel_Management_Project_WPF.Utilities;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace DataBindingAndViewsTestProject.ViewModels
{
public class AppVM : ObservableObject
{
//Create a property that controls current view
private object _currentView;
public object CurrentView
{
get { return _currentView; }
set { OnPropertyChanged(ref _currentView, value);
}
}
//Instantiate the relaycommands, we will need to instantiate relaycommand objects for every command we need to perform.
//This means that we will need to do this for preses of all buttons
public RelayCommand View1ButtonCommand { get; private set; }
public RelayCommand View2ButtonCommand { get; private set; }
public AppVM()
{
CurrentView = new DefaultVM();
View1ButtonCommand = new RelayCommand(ShowView1, AlwaysTrueCommand);
View2ButtonCommand = new RelayCommand(ShowView2, AlwaysTrueCommand);
}
public void ShowView1(object dummy)
{
CurrentView = new View1();
}
public void ShowView2(object dummy)
{
CurrentView = new View2();
}
public bool AlwaysTrueCommand(object dummy)
{
return true;
}
}
}
Main Window.xaml
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="200"></ColumnDefinition>
<ColumnDefinition Width="600"></ColumnDefinition>
</Grid.ColumnDefinitions>
<StackPanel Grid.Column="0">
<Button x:Name="view1Button" Content="Go to View 1" Margin="10" Command="{Binding View1ButtonCommand}"></Button>
<Button x:Name="view2Button" Content="Go to View 2" Margin="10" Command="{Binding View2ButtonCommand}"></Button>
</StackPanel>
<Grid Grid.Column="1">
<ContentControl Content="{Binding CurrentView}"></ContentControl>
</Grid>
</Grid>
</Window>
View1.xaml
<UserControl x:Class="DataBindingAndViewsTestProject.Views.View1"
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"
xmlns:local="clr-namespace:DataBindingAndViewsTestProject.Views"
mc:Ignorable="d"
d:DesignHeight="450" d:DesignWidth="800"
xmlns:vm="clr-namespace:DataBindingAndViewsTestProject.ViewModels">
<UserControl.Resources>
<vm:AppVM x:Name="AppVMinView1" x:Key="AppVMinView1"></vm:AppVM>
</UserControl.Resources>
<UserControl.DataContext>
<vm:View1VM></vm:View1VM>
</UserControl.DataContext>
<Grid Background="Aqua">
<StackPanel Margin="100">
<TextBlock Text="First Name"/>
<TextBox x:Name="firstNameTextBoxView1" Text="{Binding View1InfoClass.FirstName, Mode=OneWayToSource, UpdateSourceTrigger=PropertyChanged}"></TextBox>
<TextBlock Text="Last Name"/>
<TextBox x:Name="lastNameTextBoxView1" Text="{Binding View1InfoClass.LastName, Mode=OneWayToSource, UpdateSourceTrigger=PropertyChanged}"></TextBox>
<TextBlock Text="Random Useless Number" ></TextBlock>
<TextBox x:Name="randomUselessNumberView1" Text="{Binding View1InfoClass.Number, Mode=OneWayToSource, UpdateSourceTrigger=PropertyChanged}"></TextBox>
<TextBlock Text="First Name Entered"></TextBlock>
<TextBlock Text="{Binding View1InfoClass.FirstName}"></TextBlock>
<TextBlock Text="Last Name Entered" ></TextBlock>
<TextBlock Text="{Binding View1InfoClass.LastName}"></TextBlock>
<TextBlock Text="Random Useless Number Entered"></TextBlock>
<TextBlock Text="{Binding View1InfoClass.Number}"></TextBlock>
<Button DataContext="{StaticResource AppVMinView1}" Content="Go to view2" Height="20" Width="70" Command="{Binding View2ButtonCommand}" />
</StackPanel>
</Grid>
</UserControl>
View2.xaml
<UserControl x:Class="DataBindingAndViewsTestProject.Views.View2"
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"
xmlns:local="clr-namespace:DataBindingAndViewsTestProject.Views"
xmlns:vm="clr-namespace:DataBindingAndViewsTestProject.ViewModels"
mc:Ignorable="d"
d:DesignHeight="450" d:DesignWidth="800">
<UserControl.Resources>
<vm:View1VM x:Key="View1VMInView2" x:Name="View1VMInView2"></vm:View1VM>
</UserControl.Resources>
<UserControl.DataContext>
<vm:View2VM></vm:View2VM>
</UserControl.DataContext>
<Grid Background="Beige">
<StackPanel Margin="100">
<TextBlock Text="First Name"/>
<TextBox x:Name="firstNameTextBoxView2" Text="{Binding View2InfoClass.FirstName, Mode=OneWayToSource,UpdateSourceTrigger=PropertyChanged}"></TextBox>
<TextBlock Text="Last Name"/>
<TextBox x:Name="lastNameTextBoxView2" Text="{Binding View2InfoClass.LastName, Mode=OneWayToSource,UpdateSourceTrigger=PropertyChanged}"></TextBox>
<TextBlock Text="Random Useless Number"></TextBlock>
<TextBox x:Name="randomUselessNumberView2" Text="{Binding View2InfoClass.Number, Mode=OneWayToSource,UpdateSourceTrigger=PropertyChanged}"></TextBox>
<TextBlock Text="First Name Entered"></TextBlock>
<TextBlock DataContext="View1InView2" Text="{Binding View1InfoClass.FirstName}" ></TextBlock>
<TextBlock Text="Last Name Entered"></TextBlock>
<TextBlock></TextBlock>
<TextBlock Text="Random Useless Number Entered"></TextBlock>
<TextBlock ></TextBlock>
</StackPanel>
</Grid>
</UserControl>
Model (if relevant)
public class InfoClass:ObservableObject
{
private string _firstName;
public string FirstName
{
get { return _firstName; }
set {
OnPropertyChanged(ref _firstName, value);
}
}
private string _lastName;
public string LastName
{
get { return _lastName; }
set { OnPropertyChanged(ref _lastName, value); }
}
private int _number;
public int Number
{
get { return _number; }
set { OnPropertyChanged(ref _number, value); }
}
}
I'm tring to databind properties of an ObservableCollection to a ListBox (Just the Title property for example).
By clicking on one of the ListItem (with an event ), i'd like to display all the properties of the Collection into a StackPanel. After many tries, I still don't know how can I figure it out...
Here is my code behind :
public partial class TestListView : Window
{
public TestListView()
{
ObservableCollection<Programme> pgr = new ObservableCollection<Programme>();
pgr = readfile();
InitializeComponent();
}
public class Programme
{
public String Title { get; set; }
public String Date { get; set; }
public String Chaine { get; set; }
public Programme(String Title, String Date, String Chaine)
{
this.Title = Title;
this.Date = Date;
this.Chaine = Chaine;
}
}
Here is my XAML :
<Window x:Class="Test.TestListView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:Test;assembly=Test"
Title="TestListView" Height="500" Width="1000" x:Name="Window">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="249*"/>
<ColumnDefinition Width="743*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="20*"/>
<RowDefinition Height="428*"/>
<RowDefinition Height="21*"/>
</Grid.RowDefinitions>
<ListBox Name="l1" ItemsSource="{Binding pgr}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding Title}"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
<StackPanel Grid.Column="1" Grid.Row="1">
<TextBox Margin="343,0,0,0" x:Name="Recherche"></TextBox>
<Button Height="37" Margin="669,0,0,0" ></Button>
<TextBlock x:Name="t1" Margin="214,0,293,0" Height="33" />
</StackPanel>
</Grid>
</Window>
You need to bind your data to (public) properties. Also, you don't need to use ObservableCollection; any selection changes will be picked up anyhow.
Here's a working sample, with layout and other bits and pieces changed to make it compile for me:
public partial class MainWindow
{
public IList<Programme> pgr { get; }
public MainWindow()
{
pgr = new List<Programme>
{
new Programme("First", "FirstDate", "FirstChaine"),
new Programme("Second", "SecondDate", "SecondChaine"),
new Programme("Third", "ThirdDate", "ThirdChaine"),
};
InitializeComponent();
}
public class Programme
{
// No changes
}
}
...and the XAML:
<Window
x:Name="self"
x:Class="WpfApplication1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:WpfApplication1"
mc:Ignorable="d"
Title="MainWindow"
Height="350"
Width="525">
<StackPanel DataContext="{Binding ElementName=self}" Orientation="Horizontal">
<ListBox Name="l1" ItemsSource="{Binding pgr}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding Title}"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
<StackPanel Orientation="Vertical">
<TextBox Margin="10" Text="{Binding ElementName=l1,Path=SelectedItem.Title}" />
<Button Height="37" Margin="0" Content="{Binding ElementName=l1,Path=SelectedItem.Date}"></Button>
<TextBlock Margin="10" Height="33" Text="{Binding ElementName=l1,Path=SelectedItem.Chaine}" />
</StackPanel>
</StackPanel>
</Window>
Note the bindings that reference the selected item:
Text="{Binding ElementName=l1,Path=SelectedItem.Title}"
I've created an example based on MVVM
Main window XAML:
<Window x:Class="LearnMVVM.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:LearnMVVM"
xmlns:System="clr-namespace:System;assembly=mscorlib"
Title="MainWindow" Height="350" Width="525">
<Window.DataContext>
<local:ViewModel />
</Window.DataContext>
<Window.Resources>
<ObjectDataProvider x:Key="operationTypeEnum" MethodName="GetValues" ObjectType="{x:Type System:Enum}">
<ObjectDataProvider.MethodParameters>
<x:Type TypeName="local:OperationType"/>
</ObjectDataProvider.MethodParameters>
</ObjectDataProvider>
<DataTemplate DataType="{x:Type local:SomeUserControlViewModel}">
<local:SomeUserControl />
</DataTemplate>
</Window.Resources>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition Width="25"/>
<ColumnDefinition/>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="25"/>
<RowDefinition Height="25"/>
<RowDefinition />
</Grid.RowDefinitions>
<TextBox Grid.Column="0" Grid.Row="0" Margin="2" Text="{Binding Path=A, Mode=TwoWay}"/>
<TextBlock Grid.Column="1" Grid.Row="0" Text="+" TextAlignment="Center" VerticalAlignment="Center" Height="16" Margin="0,4,0,5"/>
<TextBox Grid.Column="2" Grid.Row="0" Margin="2" Text="{Binding Path=B, Mode=TwoWay}"/>
<Button Grid.Column="3" Grid.Row="0" Margin="2" Content="Посчитать" Command="{Binding ClickCommand}"/>
<TextBox Grid.Column="4" Grid.Row="0" Margin="2" IsReadOnly="True" Text="{Binding Path=Summa, Mode=TwoWay}"/>
<ComboBox Grid.Column="2" Grid.Row="1" SelectedItem="{Binding Path=SomeUserControl.Operation, Mode=TwoWay}" ItemsSource="{Binding Source={StaticResource operationTypeEnum}}" />
<ContentControl Grid.Column="2" Grid.Row="2" BorderThickness="3" BorderBrush="Black" Content="{Binding Path=SomeUserControl}" />
</Grid>
</Window>
XAML of the SomeUserControl:
<UserControl x:Class="LearnMVVM.SomeUserControl"
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"
xmlns:learnMvvm="clr-namespace:LearnMVVM"
xmlns:diag="clr-namespace:System.Diagnostics;assembly=WindowsBase"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<UserControl.DataContext>
<learnMvvm:SomeUserControlViewModel />
</UserControl.DataContext>
<DockPanel>
<TextBox DockPanel.Dock="Top" Margin="10" Text="{Binding Path=A, Mode=TwoWay, diag:PresentationTraceSources.TraceLevel=High}" />
<Label DockPanel.Dock="Top" Content="{Binding Path=Operation, diag:PresentationTraceSources.TraceLevel=High}" />
<TextBox DockPanel.Dock="Top" Margin="10" Text="{Binding Path=B, Mode=TwoWay, diag:PresentationTraceSources.TraceLevel=High}" />
<Button DockPanel.Dock="Top" Content="=" Margin="20" Command="{Binding CalculateOperationComamnd, Mode=TwoWay, diag:PresentationTraceSources.TraceLevel=High}" />
<Label DockPanel.Dock="Top" Margin="10" Content="{Binding Path=Result, diag:PresentationTraceSources.TraceLevel=High}" />
</DockPanel>
</UserControl>
ViewModel of the SomeCustomUserControl:
using System;
using System.ComponentModel;
using System.Windows.Input;
namespace LearnMVVM
{
public enum OperationType
{
Sum,
Sub,
Div,
Mul
}
public class SomeUserControlViewModel : INotifyPropertyChanged
{
public double A { get; set; }
public double B { get; set; }
//Команды
private ICommand calculateOperationCommand;
public ICommand CalculateOperationComamnd
{
get
{
return calculateOperationCommand;
}
set
{
if (calculateOperationCommand != value)
{
calculateOperationCommand = value;
OnPropertyChanged("CalculateOperationComamnd");
}
}
}
private OperationType operation;
public OperationType Operation
{
get
{
return operation;
}
set
{
if (operation != value)
{
operation = value;
switch (operation)
{
case OperationType.Sum:
CalculateOperationComamnd = new RelayCommand(arg => OperationSum());
break;
case OperationType.Sub:
CalculateOperationComamnd = new RelayCommand(arg => OperationSub());
break;
case OperationType.Div:
CalculateOperationComamnd = new RelayCommand(arg => OperationDiv());
break;
case OperationType.Mul:
CalculateOperationComamnd = new RelayCommand(arg => OperationMul());
break;
}
OnPropertyChanged("Operation");
}
}
}
private void OperationSum()
{
Result = A + B;
}
private void OperationSub()
{
Result = A - B;
}
private void OperationDiv()
{
Result = A/B;
}
private void OperationMul()
{
Result = A*B;
}
private double result;
public double Result
{
get { return result; }
set
{
if (Math.Abs(result - value) > 0.0001)
{
result = value;
OnPropertyChanged("Result");
}
}
}
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
}
Problem: the custom control does not change, when i'm changing selected item from the combo box and the "calculate button has no effect.
Actually all properties within of SomeCustomControlViewModel are updated as expected, but there is no effect in the main windows.
Have i missed something?
Operation is not a property of SomeUserControl. It is a property of SomeUserControl's viewmodel -- reachable as the control's DataContext. Try binding ComboBox.SelectedItem like so:
SelectedItem="{Binding Path=SomeUserControl.DataContext.Operation, Mode=TwoWay}"
The change is that I added DataContext to the path.
This is why you don't use viewmodels with custom controls, if you really want to use them as controls. You write a control class deriving from Control, and give it dependency properties. Operation should be a dependency property of a class derived from Control, not a notifying property on a viewmodel. Then you define UI for it by applying a ControlTemplate via a default Style.
What you've got here is really a child viewmodel. With that type of arrangement, ordinarily the parent viewmodel would provide an instance of the child viewmodel, and bind it to the child control itself. Then anybody who wanted to use a property of the child viewmodel would bind ChildVM.WhateverProperty.
I have an application that has a Navigation Menu that uses Commands to go from page to page.
The Navigation Menu has been created in Xaml and i have it stored in Navigation.xaml see below
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:vm="clr-namespace:Cirdan.Wpf.Navigation"
xmlns:infrastructure="clr-namespace:Cirdan.Wpf.Infrastructure">
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="/Cirdan.Wpf;component/Resources/Styles/Stylesheet.xaml" />
</ResourceDictionary.MergedDictionaries>
<DataTemplate x:Key="Navigation" >
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="4*"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<UniformGrid Grid.Row="0" Columns="1">
<Button DataContext="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type vm:NavigationViewModelBase}}}" Visibility="{Binding ElementName=Menu, Path=IsChecked, Converter={StaticResource VisibilityConverter}}" Command="{Binding ViewerPageCmd}" >Viewer Screen</Button>
<Button DataContext="{Binding NavigationViewModel, Source={x:Static infrastructure:MainWindow.LocatorX}}" Visibility="{Binding ElementName=Menu, Path=IsChecked, Converter={StaticResource VisibilityConverter}}" Command="{Binding}" >Acquisition Screen</Button>
<Button DataContext="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type vm:NavigationViewModelBase}}}" Visibility="{Binding ElementName=Menu, Path=IsChecked, Converter={StaticResource VisibilityConverter}}" Command="{Binding WorklistPageCmd}" >Worklist Screen</Button>
</UniformGrid>
<ToggleButton Grid.Row="1" Style="{StaticResource ToggleBtnToolStyle}" x:Name="Menu" IsChecked="true" Background="Transparent" BorderThickness="0" >
<StackPanel Orientation="Horizontal">
<ContentPresenter Margin="5" Height="50" Content="{StaticResource MenuIcon}"></ContentPresenter>
<Viewbox>
<TextBlock Margin="5" Style="{StaticResource TxtToolStyle}">Menu</TextBlock>
</Viewbox>
</StackPanel>
</ToggleButton>
</Grid>
</DataTemplate>
The ViewModel that I am trying to Bind these Button Commands to is called NavigationViewModelBase.cs
using GalaSoft.MvvmLight;
using GalaSoft.MvvmLight.Command;
using GalaSoft.MvvmLight.Messaging;
namespace Cirdan.Wpf.Navigation
{
public abstract class NavigationViewModelBase : ViewModelBase
{
private List<DicomMetadataModel> _dicomMetadata;
//Navigation Cmd
public ICommand AcquisitionPageCmd { get; private set; }
public ICommand ManualEntryWindowCmd { get; private set; }
public ICommand SessionWindowCmd { get; private set; }
public ICommand SettingsWindowCmd { get; private set; }
public ICommand StudyInfoPageCommandCmd { get; private set; }
public ICommand ViewerPageCmd { get; private set; }
public ICommand WorklistPageCmd { get; private set; }
protected NavigationViewModelBase()
{
AcquisitionPageCmd = new RelayCommand(() => Messenger.Default.Send(new GoToPageMessage(Pages.AcquisitionScreen)));
ManualEntryWindowCmd = new RelayCommand(() => Messenger.Default.Send(new ShowDialogMessage(Pages.ManualEntry, DicomMetadata)));
SessionWindowCmd = new RelayCommand(() => Messenger.Default.Send(new ShowDialogMessage(Pages.Session)));
SettingsWindowCmd = new RelayCommand(() => Messenger.Default.Send(new ShowDialogMessage(Pages.Settings)));
ViewerPageCmd = new RelayCommand(() => Messenger.Default.Send(new GoToPageMessage(Pages.Viewer)));
WorklistPageCmd = new RelayCommand(() => Messenger.Default.Send(new GoToPageMessage(Pages.Worklist)));
}
}
}
On each page i then use the following code to add the Navigation
<ContentControl Grid.Column="2" Grid.Row="2" ContentTemplate="{StaticResource Navigation }" />
At the moment I'm not getting any errors, and when I have set the DataContext in one of my buttons above, when I go to bind my commands i can see all the properties of that Viewmodel so that bit is working correctly, However when i run the program and click on these buttons nothing is happening.
Thanks for any help
Ancestor Binding will only work for element in visualtree/view or simply elemnts in your page. A viewModel is not anywhere in the page as a control. So in place of viewModel give the type of view which has NavigationViewModelBase as datacontext.write binding As below (if your view/control is NavigationView the binding will be). and in path write the property of vm:NavigationViewModelBase
class :
<Button DataContext="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type v:NavigationView}}, path= PropertyYouWantToBind}"
just make sure if you have not defined DataContext for any other control in hierarchy, Button will be getting same DataContext as view, then you just have to bind the command. which you have already done correctly.
if you have not given the DataContext to any control in your view then just give that to you contentControl or Grid. simply as
<Grid>
<Grid.DataContext>
<vm:NavigationViewModelBase />
</Grid.DataContext>
<Grid.RowDef.......
and then use simple binding for command.
RelativeSource FindAncestor looks for ancestors in VisualTree.
VisualTree can look like:
Window
Grid
TextBlock
TextBox
Button
ViewModels are not in visual three
For example ancestors of Button are Grid and Window in this case.
How to do it then?
well, create custom UserControl instead ContentControl with ContentTemplate in ResourceDictionary.
In the usercontrol set DataContext to the class that inherits from NavigationViewModelBase.
then the binding will be simple:
<UniformGrid Grid.Row="0" Columns="1">
<Button Command="{Binding ViewerPageCmd}">Viewer Screen</Button>
<Button Command="{Binding AcquisitionPageCmd}">Acquisition Screen</Button>
<Button Command="{Binding WorklistPageCmd}" >Worklist Screen</Button>
</UniformGrid>
I have a ComboBox in ItemsControl .I use WPF and MVVM, I have problem to figure out the binding to ComboBox, would someone give me a hand for this. XAML and VM as following:
<Window x:Class="OutageManagement.Views.MarketAssignmentsView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
Title="Market Selection"
WindowStartupLocation="CenterOwner"
Width="700" Height="850"
DataContext="{Binding MarketAssignmentsVM, Source={StaticResource Locator}}" >
<Grid>
<ItemsControl ItemsSource="{Binding USMarket}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition></ColumnDefinition>
<ColumnDefinition></ColumnDefinition>
</Grid.ColumnDefinitions>
<Label Content="{Binding MarketName}" Height="28"
HorizontalAlignment="Left" Name="lblUSMarketName"
VerticalAlignment="Center" />
<ComboBox Grid.Column="1" Height="23" HorizontalAlignment="Left"
Name="cbUSUsers" VerticalAlignment="Center" MinWidth="140"
ItemsSource="{Binding RelativeSource={RelativeSource
AncestorType=Window}, Path=UserList}"
DisplayMemberPath="UserName"
SelectedValue="{Binding SelectedUserID}"
SelectedValuePath="UserID"/>
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</Grid>
</Window>
ViewModel :
public class MarketAssignmentsViewModel : ViewModelBase
{
#region Data
ObservableCollection<NOCUserViewModel> _userList;
ObservableCollection<MarketAssignmentViewModel> _usMarket;
ObservableCollection<MarketAssignmentViewModel> _caMarket;
#endregion
#region Constructor
public MarketAssignmentsViewModel()
{
GetUserList();
GetMarketAssignments();
}
#endregion
#region Properties
public ObservableCollection<NOCUserViewModel> UserList
{
get { return _userList; }
}
public ObservableCollection<MarketAssignmentViewModel> USMarket
{
get { return _usMarket; }
}
public ObservableCollection<MarketAssignmentViewModel> CAMarket
{
get { return _caMarket; }
}
#endregion
.
.
.
}
The problem is that you're trying to access the UserList as a property of the Window, instead of a property of the Window's DataContext...
Modify the ItemsSource like this:
<ComboBox ItemsSource="{Binding RelativeSource={RelativeSource FindAncestor
AncestorType=Window}, Path=DataContext.UserList}" ... />
I recommend always looking in the Output window when you have binding problems, you probably would have seen something like this:
System.Windows.Data Error: 40 : BindingExpression path error: 'UserList' property not found on 'object' ''MarketAssignmentsView' (Name='')'.