<Button Click="MyClickMethod" /> works fine; the XAML type provider exposes MyClickMethod as a virtual method in the code-behind.
On the other hand, override this.MyDoubleClickMethod (_, _) gets the pretty red underlining for <ListBox MouseDoubleClick="MyDoubleClickMethod" />, and of course my program fails to compile.
If ListBox events aren't supported, then it sure would have been nice to know this before I got three days into coding my application. Is FsXaml well documented anywhere (and I don't mean the source code)? What's the generally accepted work-around for my problem?
EDIT : Here are my code files (minus AssemblyInfo.fs and App.* boilerplate), in Solution Explorer order:
MainViewModel.fs:
namespace MyWpf.ViewModels
open ViewModule
open ViewModule.FSharp
type MainViewModel () as self =
inherit ViewModelBase ()
let myItems = self.Factory.Backing (<# self.MyItems #>, Array.empty)
do
self.MyItems <- [| "cheeseburger"; "French fries"; "chocolate shake" |]
member this.MyItems
with get () = lock myItems (fun () -> myItems.Value)
and private set value = lock myItems (fun () -> myItems.Value <- value)
MainView.xaml.fs:
namespace MyWpf.Views
open System.Windows
type MainViewBase = FsXaml.XAML<"MainView.xaml">
type MainView () =
inherit MainViewBase ()
override this.MyDoubleClickMethod (_, _) = MessageBox.Show "click!" |> ignore
MainView.xaml:
<UserControl
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:viewModels="clr-namespace:MyWpf.ViewModels;assembly=MyWpf">
<UserControl.DataContext>
<viewModels:MainViewModel />
</UserControl.DataContext>
<Grid>
<ListBox
Name="MyList"
Width="300"
Height="224"
Margin="10,4,10,4"
HorizontalAlignment="Center"
VerticalAlignment="Center"
ItemsSource="{Binding MyItems}"
MouseDoubleClick="MyDoubleClickMethod" />
</Grid>
</UserControl>
MainWindow.xaml.fs:
namespace MyWpf.Windows
type MainWindow = FsXaml.XAML<"MainWindow.xaml">
MainWindow.xaml:
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:views="clr-namespace:MyWpf.Views;assembly=MyWpf"
Width="320"
Height="240"
ResizeMode="CanMinimize"
WindowStartupLocation="CenterScreen">
<Grid>
<views:MainView />
</Grid>
</Window>
Related
I was recently working on a user control, let's name it TestUserControl, and used two of its instances on one page.
While I was testing, I noticed, that when I type something into the values of upper TestUserControl, go to another page then go back to the first page - the second instance of TestUserControl is filled with values that had been typed into the first one (and even elements which are not part of user control of type TestUserControl are affected!).
Here are the screenshots of described behavior .
And the code of a simple project from which this screenshots come:
Landing page:
<Page x:Class="PageNavigation.Pages.Landing"
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:PageNavigation.Pages"
xmlns:controls="clr-namespace:PageNavigation.Controls"
xmlns:n="clr-namespace:PageNavigation"
mc:Ignorable="d"
d:DesignHeight="200"
d:DesignWidth="800"
Title="Landing">
<Grid Background="White"
ButtonBase.Click="Grid_Click">
<WrapPanel Margin="5">
<TextBlock Margin="0 25"
Text="I am a simple text block" />
<n:NavButton Text="Accounts"
ImageSource="/Images/Accounts.png"
NavUri="/Pages/Accounts.xaml" />
<n:NavButton Text="Bills"
ImageSource="/Images/Billing.png"
NavUri="/Pages/Bills.xaml" />
<n:NavButton Text="Employees"
ImageSource="/Images/Employees.png"
NavUri="/Pages/Employees.xaml" />
<n:NavButton Text="Setting"
ImageSource="/Images/Settings.png"
NavUri="/Pages/Setting.xaml" />
<StackPanel Orientation="Horizontal">
<TextBlock Text="User controls:" />
<controls:TestUserControl Width="150"/>
<controls:TestUserControl Width="150"/>
</StackPanel>
</WrapPanel>
</Grid>
</Page>
using System.Windows;
using System.Windows.Controls;
namespace PageNavigation.Pages
{
public partial class Landing : Page
{
public Landing()
{
InitializeComponent();
}
private void Grid_Click(object sender, RoutedEventArgs e)
{
if (e.OriginalSource is not NavButton ClickedButton)
return;
NavigationService.Navigate(ClickedButton.NavUri);
}
}
}
My testing user control:
<UserControl x:Class="PageNavigation.Controls.TestUserControl"
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:PageNavigation.Controls"
mc:Ignorable="d"
d:DesignHeight="450" d:DesignWidth="800">
<StackPanel Margin="5">
<TextBox/>
<TextBox/>
<TextBox/>
<StackPanel Margin="10">
<ComboBox>
<ComboBoxItem>Item 1</ComboBoxItem>
<ComboBoxItem>Item 2</ComboBoxItem>
<ComboBoxItem>Item 3</ComboBoxItem>
</ComboBox>
</StackPanel>
<ToggleButton>Toggle me!</ToggleButton>
</StackPanel>
</UserControl>
using System.Windows.Controls;
namespace PageNavigation.Controls
{
public partial class TestUserControl : UserControl
{
public TestUserControl()
{
InitializeComponent();
}
}
}
Navigation button to another pages (these one with images):
using System;
using System.Windows;
using System.Windows.Controls.Primitives;
using System.Windows.Media;
namespace PageNavigation
{
public class NavButton : ButtonBase
{
static NavButton()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(NavButton), new FrameworkPropertyMetadata(typeof(NavButton)));
}
public static readonly DependencyProperty ImageSourceProperty = DependencyProperty.Register("ImageSource", typeof(ImageSource), typeof(NavButton), new PropertyMetadata(null));
public static readonly DependencyProperty TextProperty = DependencyProperty.Register("Text", typeof(string), typeof(NavButton), new PropertyMetadata(null));
public static readonly DependencyProperty NavUriProperty = DependencyProperty.Register("NavUri", typeof(Uri), typeof(NavButton), new PropertyMetadata(null));
public ImageSource ImageSource
{
get { return (ImageSource)GetValue(ImageSourceProperty); }
set { SetValue(ImageSourceProperty, value); }
}
public string Text
{
get { return (string)GetValue(TextProperty); }
set { SetValue(TextProperty, value); }
}
public Uri NavUri
{
get { return (Uri)GetValue(NavUriProperty); }
set { SetValue(NavUriProperty, value); }
}
}
}
One of example pages which contains back button:
<Page x:Class="PageNavigation.Pages.Employees"
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:PageNavigation.Pages"
mc:Ignorable="d"
d:DesignHeight="450"
d:DesignWidth="800"
Title="Employees">
<Grid Background="White">
<Button Content="Back"
Padding="3"
Command="NavigationCommands.BrowseBack"
BorderThickness="0"
HorizontalAlignment="Left"
VerticalAlignment="Top"
Margin="5,5,0,0" />
<Label Content="Employees"
FontSize="50"
HorizontalAlignment="Center"
VerticalAlignment="Center" />
</Grid>
</Page>
using System.Windows.Controls;
namespace PageNavigation.Pages
{
public partial class Employees : Page
{
public Employees()
{
InitializeComponent();
}
}
}
Main window:
<Window x:Class="PageNavigation.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:PageNavigation"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<Grid>
<Frame Source="/Pages/Landing.xaml" NavigationUIVisibility="Hidden"/>
</Grid>
</Window>
using System.Windows;
namespace PageNavigation
{
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
}
}
I'm using for the navigation System.Windows.Navigation.NavigationService and Frame, which seems to be important, as I couldn't reproduce this bug in a simple application that uses switching ContentControl and custom NavigationService.
When I use binding to view model in TestUserControl values, the problem seems to disappear, but what if I do not need binding, because I use elements of control to manage its internal behavior only - using for example toggle button to hide/show content of a text box field?
I was looking for an explanation for this behavior, but could not find any. I was reading about defining user controls, journal in Navigation Service, Data Context, and keeping alive pages when using Frames, but found nothing about user controls magically cloning their values to other controls.
I understand I could miss something simple or I defined all my user controls wrongly, but... this is not a behavior I would expect from a user control created in the simplest possible way.
I would appreciate it if someone could help me and answer my questions:
why is this happening? Is it a bug in WPF itself?
is this possible to create "safe" user control without necessarily using binding its values to an external source - and how to do it properly?
Sorry if I did not provide all the required information, but I don't know which information will be valuable as it seems to be a vague problem. I will try to answer any questions.
It's the frame journal which stores state for pages which have been shown.
If you don't go back to the previous page in your real app you could do:
NavigationService.RemoveBackEntry()
After you navigate.
That should remove whatever the journal just got.
You could also try giving things explicit X:Name and see if that allows the journal mechanism to differentiate.
Personally, I avoid frames and pages and I suggest you might consider using contentpresenter and usercontrols instead. I prefer viewmodel first navigation.
The discovered workaround is to bind values of controls to properties in code behind (it solves the problem) - at least visually.
I can't figure out what am I doing wrong and why my the text doesn't show up.
<Window x:Class="Test"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Test" Height="300" Width="300" x:Name="TheWindow">
<TextBlock Text="{Binding ElementName=TheWindow,Path=TestObject, Mode=OneTime}" FontSize="12"></TextBlock>
And the code behind the window:
public partial class Test : Window
{
public Test()
{
InitializeComponent();
}
public const string TestObject = "I just want to be shown";
}
}
You can only bind to properties, read some references first...
(In this case you would use x:Static, still, read the references)
I would like to know. How can I use dxb:Barbuttonitem together with caliburn micro.
I tried to write this code. But unfortunately it did not work.
<Window x:Class="WpfApplication1.ShellView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:cal="http://www.caliburnproject.org"
xmlns:dxb="http://schemas.devexpress.com/winfx/2008/xaml/bars"
xmlns:dxr="http://schemas.devexpress.com/winfx/2008/xaml/ribbon"
Title="ShellView"
Width="300"
Height="300">
<Grid>
<dxb:BarManager Name="barManager1">
<dxb:BarManager.Items>
<dxb:BarButtonItem Name="Connect" Content="barButtonItem1" />
</dxb:BarManager.Items>
<DockPanel >
<dxr:RibbonControl DockPanel.Dock="Top">
<dxr:RibbonDefaultPageCategory Name="ribbonDefaultPageCategory1" Caption="defaultCategory">
<dxr:RibbonPage Caption="Home">
<dxr:RibbonPageGroup Name="ribbonPageGroup1" Caption="Tools">
<dxb:BarButtonItemLink BarItemName="Connect" />
</dxr:RibbonPageGroup>
</dxr:RibbonPage>
</dxr:RibbonDefaultPageCategory>
</dxr:RibbonControl>
<dxr:RibbonStatusBarControl DockPanel.Dock="Bottom" />
</DockPanel>
</dxb:BarManager>
</Grid>
[Export(typeof(IShell))]
public class ShellViewModel : PropertyChangedBase, IShell
{
public void Connect()
{
MessageBox.Show(string.Format("Hello {0}!", "aaa"));
}
public bool CanConnect()
{
return false;
}
}
If I use a standard button, all works fine.
This is not supported by CM since BarButtonItem inherits from FrameworkContentElement (CM supports messages on FrameworkElement only).
The CM forum post can be found here
There's a workaround for this problem that let's you trigger actions from DX's Bar items. You can use a static bar item and put any of standard controls (or buttons) inside then trigger actions from those elements. Example:
<dxb:BarStaticItem x:Name="LoadAllBarItem">
<dxb:BarStaticItem.ContentTemplate>
<DataTemplate>
<Button Content="Load all"
cal:Message.Attach="LoadAction"/>
</DataTemplate>
</dxb:BarStaticItem.ContentTemplate>
</dxb:BarStaticItem>
I have a WPF app which I am using Blend to style.
One of my view models is of the type:
public Dictionary<DateTime, ObservableCollection<MyViewModel>> TimesAndEvents
But when I try to create some sample data in Expression Blend it simply doesnt create the XAML for this property.
Can you create a data type like this in XAML? The non-design time support is killing my productivity.
Regarding your last question: unfortunately, you cannot easily instantiate dictionaries in WPF. I believe this answer explains that part well. The book, WPF 4.5 Unleashed provides a good summary of what the linked answer states:
A common workaround for this limitation (not being able to instantiate
a dictionary in WPF's version of XAML) is to derive a non-generic
class from a generic one simply so it can be referenced from XAML...
But even then, instantiating that dictionary in xaml is again, in my opinion, a painful process. Additionally, Blend does not know how to create sample data of that type.
Regarding the implicit question of how to get design time support: there are a few ways to achieve design time data in WPF, but my preferred method at this point in time for complex scenarios is to create a custom DataSourceProvider. To give credit where it is due: I got the idea from this article (which is even older than this question).
The DataSourceProvider Solution
Create a class that implements DataSourceProvider and returns a sample of your data context. Passing the instantiated MainWindowViewModel to the OnQueryFinished method is what makes the magic happen (I suggest reading about it to understand how it works).
internal class SampleMainWindowViewModelDataProvider : DataSourceProvider
{
private MainWindowViewModel GenerateSampleData()
{
var myViewModel1 = new MyViewModel { EventName = "SampleName1" };
var myViewModel2 = new MyViewModel { EventName = "SampleName2" };
var myViewModelCollection1 = new ObservableCollection<MyViewModel> { myViewModel1, myViewModel2 };
var timeToMyViewModelDictionary = new Dictionary<DateTime, ObservableCollection<MyViewModel>>
{
{ DateTime.Now, myViewModelCollection1 }
};
var viewModel = new MainWindowViewModel()
{
TimesAndEvents = timeToMyViewModelDictionary
};
return viewModel;
}
protected sealed override void BeginQuery()
{
OnQueryFinished(GenerateSampleData());
}
}
All that you have to do now is add your data provider as a sample data context in your view:
<Window x:Class="SampleDataInBlend.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:SampleDataInBlend"
mc:Ignorable="d"
Title="MainWindow" Height="200" Width="300">
<d:Window.DataContext>
<local:SampleMainWindowViewModelDataProvider/>
</d:Window.DataContext>
<Grid>
<ListBox ItemsSource="{Binding TimesAndEvents}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Key}"/>
<ListBox ItemsSource="{Binding Value}">
<ListBox.ItemTemplate>
<DataTemplate DataType="{x:Type local:MyViewModel}">
<TextBlock Text="{Binding EventName}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
</Window>
Note: the 'd' in <d:Window.DataContext> is important as it tells Blend and the compiler that that specific element is for design time and it should be ignored when the file is compiled.
After doing that, my design view now looks like the following:
Setting up the problem
I started with 5 classes (2 were generated from the WPF project template, which I recommend using for this):
MyViewModel.cs
MainWindowViewModel.cs
MainWindow.xaml
App.xaml
MyViewModel.cs
public class MyViewModel
{
public string EventName { get; set; }
}
MainWindowViewModel.cs
public class MainWindowViewModel
{
public IDictionary<DateTime, ObservableCollection<MyViewModel>> TimesAndEvents { get; set; } = new Dictionary<DateTime, ObservableCollection<MyViewModel>>();
public void Initialize()
{
//Does some service call to set the TimesAndEvents property
}
}
MainWindow.cs
I took the generated MainWindow class and changed it. Basically, now it asks for a MainWindowViewModel and sets it as its DataContext.
public partial class MainWindow : Window
{
public MainWindow(MainWindowViewModel viewModel)
{
DataContext = viewModel;
InitializeComponent();
}
}
MainWindow.xaml
Please note the lack of the design data context from the Solution.
<Window x:Class="SampleDataInBlend.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:SampleDataInBlend"
mc:Ignorable="d"
Title="MainWindow" Height="200" Width="300">
<Grid>
<ListBox ItemsSource="{Binding TimesAndEvents}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Key}"/>
<ListBox ItemsSource="{Binding Value}">
<ListBox.ItemTemplate>
<DataTemplate DataType="{x:Type local:MyViewModel}">
<TextBlock Text="{Binding EventName}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
</Window>
App.cs
First off, remove StartupUri="MainWindow.xaml" from the xaml side as we'll be launching MainWindow from the code behind.
public partial class App : Application
{
protected override void OnStartup(StartupEventArgs e)
{
base.OnStartup(e);
var viewModel = new MainWindowViewModel();
// MainWindowViewModel needs to have its dictionary filled before its
// bound to as the IDictionary implementation we are using does not do
// change notification. That is why were are calling Initialize before
// passing in the ViewModel.
viewModel.Initialize();
var view = new MainWindow(viewModel);
view.Show();
}
}
Build and run
Now, if everything was done correctly and you fleshed out MainWindowViewModel's Initialize method (I will include my implementation at the bottom), you should see a screen like the one below when you build and run your WPF app:
What was the problem again?
The problem was that nothing was showing in the design view.
My Initialize() method
public void Initialize()
{
TimesAndEvents = PretendImAServiceThatGetsDataForMainWindowViewModel();
}
private IDictionary<DateTime, ObservableCollection<MyViewModel>> PretendImAServiceThatGetsDataForMainWindowViewModel()
{
var myViewModel1 = new MyViewModel { EventName = "I'm real" };
var myViewModel2 = new MyViewModel { EventName = "I'm real" };
var myViewModelCollection1 = new ObservableCollection<MyViewModel> { myViewModel1, myViewModel2 };
var timeToMyViewModelDictionary = new Dictionary<DateTime, ObservableCollection<MyViewModel>>
{
{ DateTime.Now, myViewModelCollection1 }
};
return timeToMyViewModelDictionary;
}
Any more I've gone the route of creating a Design Time Instance of my Viewmodel in my Locator that I reference as #ChrisW suggested above:
d:DataContext="{Binding Source={StaticResource Locator}, Path=DesignTimeVM}"
So I can have some hard-coded values to populate my lists, comboboxes, etc. Makes styling everything that much easier.
I use MVVM Light and so in my ViewModel's constructor I use a pattern like this:
if(IsInDesignMode)
{
ListUsers = new List<User>();
.
.
.
}
The code will only execute at Design Time, and you will have your Xaml UI bound to actual data.
Since Xaml 2009 support generic types, is possible write a loose xaml(can not be compiled in wpf project) like this to represent a dictionary.
Data.xaml
<gnrc:Dictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:sys="clr-namespace:System;assembly=mscorlib"
xmlns:gnrc="clr-namespace:System.Collections.Generic;assembly=mscorlib"
xmlns:om="clr-namespace:System.Collections.ObjectModel;assembly=System"
x:TypeArguments="sys:DateTime,om:ObservableCollection(x:String)">
<om:ObservableCollection x:TypeArguments="x:String">
<x:Key>
<sys:DateTime>2017/12/31</sys:DateTime>
</x:Key>
<x:String>The last day of the year.</x:String>
<x:String>Party with friends.</x:String>
</om:ObservableCollection>
<om:ObservableCollection x:TypeArguments="x:String">
<x:Key>
<sys:DateTime>2018/1/1</sys:DateTime>
</x:Key>
<x:String>Happy new year.</x:String>
<x:String>Too much booze.</x:String>
</om:ObservableCollection>
<om:ObservableCollection x:TypeArguments="x:String">
<x:Key>
<sys:DateTime>2018/1/10</sys:DateTime>
</x:Key>
<x:String>Just another year.</x:String>
<x:String>Not much difference.</x:String>
</om:ObservableCollection>
</gnrc:Dictionary>
But it is not support by designers like Blend or Visual Studio. If you put it into a xaml that associated with a designer, you will get dozens of errors. To solve this, we need a markup extension to provide value from Data.xaml by using XamlReader.Load method.
InstanceFromLooseXamlExtension.cs
public class InstanceFromLooseXamlExtension : MarkupExtension
{
public Uri Source { get; set; }
public override object ProvideValue(IServiceProvider serviceProvider)
{
if (Source == null)
{
throw new ArgumentNullException(nameof(Source));
}
Uri source;
if (Source.IsAbsoluteUri)
{
source = Source;
}
else
{
var iuc = serviceProvider?.GetService(typeof(IUriContext)) as IUriContext;
if (iuc == null)
{
throw new ArgumentException("Bad service contexts.", nameof(serviceProvider));
}
source = new Uri(iuc.BaseUri, Source);
}
WebResponse response;
if (source.IsFile)
{
response = WebRequest.Create(source.GetLeftPart(UriPartial.Path)).GetResponse();
}
else if(string.Compare(source.Scheme, PackUriHelper.UriSchemePack, StringComparison.Ordinal) == 0)
{
var iwrc = new PackWebRequestFactory() as IWebRequestCreate;
response = iwrc.Create(source).GetResponse();
}
else
{
throw new ArgumentException("Unsupported Source.", nameof(Source));
}
object result;
try
{
result = XamlReader.Load(response.GetResponseStream());
}
finally
{
response.Close();
}
return result;
}
}
This markup extension has a Uri type Source property to let user specify which xaml file to load. Then finally, use the markup extension like this.
MainWindow.xaml
<Window x:Class="WpfApp.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:WpfApp"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<ListBox ItemsSource="{local:InstanceFromLooseXaml Source=/Data.xaml}">
<ListBox.ItemTemplate>
<DataTemplate>
<Expander Header="{Binding Key}">
<ListBox ItemsSource="{Binding Value}"/>
</Expander>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Window>
In this case, I place Data.xaml in application folder, so 'Source=/Data.xaml' will be OK. Every time the designer reloaded(a rebuild will ensure it), the contents in loose xaml will be applied. The result should look like
The loose xaml can contain almost everything, like a ResourceDictionary or something with UiElements. But both Blend or Visual Studio will not check it correctly for you. In the end, hope this is enough for an answer.
I want to use MVVM approach to achieve something like below:
I have a MainWindow where i have a 3 Buttons like: a)Customers b) Orders c) Sales
By clicking on button, it should open its respective window/usercontrol xaml with customers details,orders details,sales details.
I have tried everything but culdnt able to do so.
How to achieve this using MVVM pattern. Kindly provide the solution?
Thanks
The answer depends on how you want your Customers, Orders and Sales views displayed. If you want them displayed in the same view, simply add a content control bound to a property in your main ViewModel.
For example, if you're using the MVVM Light Toolkit, your MainPage.xaml might look like...
<UserControl x:Class="MvvmLight2.MainPage"
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"
Height="300"
Width="300"
DataContext="{Binding Main, Source={StaticResource Locator}}">
<UserControl.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Skins/MainSkin.xaml" />
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</UserControl.Resources>
<StackPanel Orientation="Vertical">
<StackPanel Orientation="Horizontal">
<Button Content="Customers" Command="{Binding DisplayView}" CommandParameter="Customers" Margin="10" />
<Button Content="Orders" Command="{Binding DisplayView}" CommandParameter="Orders" Margin="10" />
<Button Content="Sales" Command="{Binding DisplayView}" CommandParameter="Sales" Margin="10" />
</StackPanel>
<ContentControl Content="{Binding CurrentView}" IsTabStop="False" Margin="10" />
</StackPanel>
</UserControl>
And your MainPageViewModel would be...
using System.Windows.Controls;
using GalaSoft.MvvmLight;
using GalaSoft.MvvmLight.Command;
namespace MvvmLight2.ViewModel
{
public class MainViewModel : ViewModelBase
{
public MainViewModel()
{
DisplayView = new RelayCommand<string>(DisplayViewCommandExecute);
}
#region Commands
public RelayCommand<string> DisplayView { get; private set; }
#endregion
#region CurrentView Property
public const string CurrentViewPropertyName = "CurrentView";
private UserControl _currentView;
public UserControl CurrentView
{
get { return _currentView; }
set
{
if (_currentView == value)
return;
_currentView = value;
RaisePropertyChanged(CurrentViewPropertyName);
}
}
#endregion
private void DisplayViewCommandExecute(string viewName)
{
switch (viewName)
{
case "Customers":
CurrentView = new CustomersView();
break;
case "Orders":
CurrentView = new OrdersView();
break;
case "Sales":
CurrentView = new SalesView();
break;
}
}
}
}
This all assumes that you have created views and view models for Customers, Orders, and Sales, and modified the ViewModelLocator to include them.
At this point, if you need to display specific information in your child views, you can create a dependency property in them, and set that from your MainViewModel before you display the view.
You may want to look into the mediator pattern . Common implementations are the Messenger class in the MVVM Light Toolkit and Event Aggregation in PRISM.
One basic workflow using this pattern... Command is called on viewmodel1. Viewmodel1 registers some message with the mediator. Viewmodel2 subscribes to that message and does something in response (like creates new view2 or changes visual state of the view2).
I tried this using Sliverlight Naviagtion Application and MVVM
http://garfoot.com/blog/2010/09/silverlight-navigation-with-the-mvvm-pattern/
Pretty simple example. No frameworks involved as such.
But using a MVVM framework makes life easier for future use.
For MVVM and Prism framework check this link..
http://blog.roboblob.com/2010/10/24/introducing-prism-navigation-framework-for-silverlight-mvvm-applications/