I've created a simple WPF application which has two Windows. The user fills in some information on the first Window and then clicks Ok which will take them to the second Window. This is working fine but I'm trying to incorporate both Windows into a single Window so just the content changes.
I managed to find this Resource management when changing window content which seems like it is what I'm after. However, I've search for ContentPresenter but couldn't find much help for how I need to use it. For example, if I use a ContentPresenter, where do I put the existing XAML elements that are in the two Windows? I'm guessing the first Window will go into the ContentPresenter but the second one will need to be put somewhere for when it needs to be switched in.
Any help would be great. A simple working example would be even better.
TIA
A ContentPresenter is normally used when restyling existing controls. It is the place where the Content of a control is placed. Instead you should use a ContentControl, which is simply a control that has a content element. Alternatively, you could directly set the Content of your window.
You extract the contents of your two existing windows into two UserControls. Then you create a new Window which will host the contents. Depending on your business logic, you set the content of that window (or that window's ContentControl if you want additional "master" content) to either of those two UserControls.
EDIT:
As a starting point. This is not complete working code, just to get you started. Note that this is bad architecture; you should probably use a MVVM or similar approach once you get this running!
<Window>
<ContentControl Name="ContentHolder" />
</Window>
<UserControl x:Class="MyFirstUserControl" /> <!-- Originally the first window -->
<UserControl x:Class="MySecondUserControl" /> <!-- Originally the second window -->
In code behind of Window:
// Somewhere, ex. in constructor
this.ContentHolder.Content = new MyFirstUserControl;
// Somewhere else, ex. in reaction to user interaction
this.ContentHolder.Content = new MySecondUserControl;
I use ContentPresenter for snapping in content. In the window, I put something like this:
<ContentPresenter Content="{Binding MainContent}" />
In the view model, I have a property called MainContent of type object:
public object MainContent { get { return (object)GetValue(MainContentProperty); } set { SetValue(MainContentProperty, value); } }
public static readonly DependencyProperty MainContentProperty = DependencyProperty.Register("MainContent", typeof(object), typeof(SomeViewModel), new FrameworkPropertyMetadata(null));
Whatever you set MainContent to will show up in the window.
To keep the separation between view and view model, I typically set the MainContent property to another view model and use a data template to map that view model to a view:
<DataTemplate DataType="{x:Type viewmodels:PlanViewModel}">
<views:PlanView />
</DataTemplate>
I put that data template in some central resource dictionary along with a bunch of other view-model-to-view mappers.
Related
I'm trying to set a new DataTemplate as a new Window resource in my MainWindow derived from the System.Windows.Window class. The code for the XAML is quite simple and looks like this:
<Window.Resources>
<DataTemplate DataType="{x:Type model:MyViewModel}">
<view:MyView />
</DataTemplate>
</Window.Resources>
What I exactly do here?
I try to show my data (MyViewModel) in or as a specific view (MyView). So far I do understand. Otherwise I wouldn't see the form itself, but the view model as a string with my.namespace.MyViewModel in the window.
But programmatically I do not understand, how to achieve the same. I know, that I have to add a new DataTemplate to the resources of my window. For this I have to "tell" the DataTemplate, which view to use (for the representation) and which data I want to represent, right?
So it must be something with:
DataTemplate template = new DataTemplate();
template.DataType = typeof(MyViewModel);
// Something, something ...
this.Resources.add(...);
Is this the right way to go? Or am I completely wrong?
I searched the web for solutions and also my WPF book, but there are only XAML implementations.
Why do I do that?
I have a headered content control which loads view models dynamically. The problem here is, that the user controls are sometimes dynamic and in case of data presentation I need to assign a specific (dynamic created) view to the data. So I try to load the current static user controls also in the way shown above.
Is there a way to go?
Or is there a better way to achieve the same results?
I am quite new to WPF development, and currently I am trying to use the MVVM on my application development. I have read a lot about MVVM navigation and switching views, but I can't find a solution for my current situation. Let's explain what it is:
First of all, I have my main View element, a Dockpanel, with some fixed areas, and a main "dynamic" area where the content should change, depending on actions:
<DockPanel>
<Label Content="Top Fixed element"/>
<StackPanel Orientation="Vertical" Height="auto" Width="150" DockPanel.Dock="Left">
<Label Content="SomeOptions"/>
<!-- some more elements -->
</StackPanel>
<Label DockPanel.Dock="Bottom" Content="Foot"/>
<ContentControl Content="{Binding CurrentMainViewElementViewModel}"/>
</DockPanel>
I have defined some DataTemplates that I would like to load in this ContentControl, here there is one of the Data Templates as example:
<Window.Resources>
<DataTemplate DataType="{x:Type ViewModel:FileLoaderVM}">
<View:FileLoaderView/>
</DataTemplate>
</Window.Resources>
This FileLoader (View and View Model are implemented, using the RelayCommand and the INotifyPropertyChanged) opens a dialog box after clicking a button, where after selecting a file it is opened and parsed, and show all the found elements inside a ListView with multiple selection(in this case, persons with their data).
What I want to do now is to load another user control in this ContentControl, when I click a button. This button is defined in my view model like this:
public ICommand LoadPersons
{
get { return new RelayCommand(param => this.loadSelectedPersons(), param => (SelectedPersons!=null && SelectedPersons.Any()));}
}
My question comes at this point, how can I modify the content of the ContentControl, loading another User Control instead of the current one directly from my view model (in this "this.loadSelectedPersons()")?
If this is not possible, how should I approach to solve this problem?
Next to this action, I want to show all the previously selected elements and manipulate in different possible ways (inserting in a DB, saving in another file and so on), and I have already for that the appropriate User Control, that I would like to show in my main view element in the ContentControl section, keeping the other elements as they are originally.
lets see if i get you right.
you have a mainviewmodel with a property (CurrentMainViewElementViewModel) bound to the ContentControl. your MainViewmodel set the FileLoaderVM to this Property. now you wanna show a "new/other" Viewmodel when a File is seleted in your FileLoaderVM?
why dont you simply expose a event from your FileLoaderVM and subscribe to this event in your MainViewModel? if you do so your MainViewModel can then set the "new/other" Viewmodel to the ContentControl
To change content of ContentControl you do not load another user control, but change value of CurrentMainViewElementViewModel (to which ContentControl.Content is bound) to a new ViewModel, which will load another UserControl (defined in DataTemplate same way as FileLoaderVM is).
This looks like a job for main ViewModel (where CurrentMainViewElementViewModel is located).
Easiest solution is to provide a method in that ViewModel
public Switch()
{
CurrentMainViewElementViewModel = SomeViewModel;
}
and call this method from FileLoaderVM.
I have a Window, and there are three types of content that can be displayed (they are all of UserControl type):
Login view
App view
Error reporting
What's the most appropriate way to switch between these? My thought was to pass instance of Window in the constructor and then addressing it's content.
Content = new LoginView(this);
And then change the content from LoginView,
public LoginView(Window wnd){
InitializeComponents();
wnd.Content = new MainView(wnd);
}
But this wouldn't update the Window's content. Is it caused by the caller (LoginView) being the window's current content? If that's the case, what would be the proper way to handle such situation?
Also note that the snippet provided doesn't include any logic. I just left it as simple as required to demonstrate the issue I'm facing.
Basically the connection between those controls is such:
Login view
- when the application starts
- when the application window sends a request (to the server) that returns unauthorized
App view
- handles all the application's features
Error view
- replaces app/login view in case of an error and informs user about what to do
You should maybe look at the MVVM pattern. Usually every user control / view should have its own view model, when using the MVVM pattern. So you can define different Views inside a MainView. Like the following example shows:
<Window.Resources>
<DataTemplate x:Key="LoginView" DataType="{x:Type ViewModel:LoginViewModel}">
<local:LoginView />
</DataTemplate>
<DataTemplate x:Key="AppView" DataType="{x:Type ViewModel:AppViewModel}">
<local:AppView />
</DataTemplate>
<Window.Resources>
So in your code of the MainView, you have to pass the appropriate ViewModel in a ContentControl. This will reference the right View.
<ContentControl Content="{Binding LoginViewModel}" />
So the DataTemplate will be shown, depending on the xxxViewModel that is passed.
I have a UserControl named "WorkspaceView" and its only purpose is to show other views as tabs. Call these views ViewA, ViewB etc. Which of these views to present should be determined on runtime, so I figured I needed a control that can present ... well ..stuff.
ContentControl to the rescue. Except ... I can't make it work. I'm trying to new up a usercontrol of type ViewA in the code behind and assign it to my MyContent, which is the ContentControl. I've tried:
public WorkspaceView()
{
InitializeComponent();
DataContext = new View(A); //Hoping that the DataContext will propagate down
}
Second attempt was
public WorkspaceView()
{
InitializeComponent();
var binding = new Binding {Source = new ViewA()};
MyContent.SetBinding(ContentControl.ContentProperty, binding);
}
In both cases, I see an empty box, but since I've hard wired a TextBlock into ViewA, I'd expect it to show me that text. What am I doing wrong?
Despite knowing that MVVM is the preferred way to develop WPF applications, I'd prefer to see how I can do this with code behind files. Later on, I will redo the application with MVVM, but first I need to get some basic understanding of WPF.
In response to the suggestions so far, I've tried
MyContent.Content = new ViewA();
but still I the text that is in ViewA does not appear. I've also at the bottom of this post included a screenshot of what the application renders.
WorkspaceView
Resource file
What is rendered
Have you tried simply doing this?
MyContent.Content = new ViewA();
EDIT
Try simplifying your code a bit and working from there. For instance:
public WorkspaceView()
{
InitializeComponent();
// Something better than UserControl should be used here
ObservableCollection<UserControl> views = new ObservableCollection<UserControl>();
views.Add(new ViewA());
views.Add(new ViewB());
DataContext = views;
}
<Border ..>
<TabControl x:Name="TabControl"
..
ItemsSource="{Binding}" />
</Border>
This code sets a WorkspaceView.DataContext to a collection of UserControls. When you specify {Binding} whithin WorkspaceView's XAML you are refering to the whole DataContext object (i.e. your collection.) This way you are setting the TabControl.ItemsSource to your collection of views.
Now you could create DataTemplates targeting the type of each view to control how each control is displayed in its tab within the TabControl.
I'm trying to make a window layout usable from different windows.
As you can see from image, I've got a logo, a left vertical progress bar and two control buttons in the bottom part of the window (plus menu bar and status bar).
Those parts should be always the same in different windows, and play/stop should be interacting run-time with the common parts but also with parts build in the middle of the window ("part in each window different").
I can't understand what i should use for creating a standard layout callable from each window where I need it, made in a way were I can replace for each of those windows just the middle part.
Any tips? I probably just need to understand the way to go (sad to be c# wpf newbie)!
You can use a content control and then just switch the content
Master page for regions
This link has what you need. You can put the page templates in a separate file if you will be doing lots of content switching
If you create a user control with a <ContentPresenter> where you want the variable content to be, you can inject your own controls into the user control.
The user control would look like:
<UserControl>
<Grid>
<!-- Header Stuff -->
<ContentPresenter Name="MyContentPresenter" />
<!-- Footer Stuff -->
</Grid>
</UserControl>
In your windows, you'd have:
<Window>
<Grid>
<MyUserControl>
<MyUserControl.Content>
<!-- your window specific code here -->
</MyUserControl.Content>
</MyUserControl>
</Grid>
</Window>
You will need to expose a property called Content on your user control that returns/sets the Content property of the ContentPresenter element on the user control.
In the code-behind of the user control:
public object Content
{
get { return MyContentPresenter.Content; }
set { MyContentPresenter.Content = value; }
}