I have this application where there is a frame and I navigated the frame to a different Page where there are certain button which must be able to navigate the frame to another page but i don't know how to change the navigate property of the frame from another class somewhere. Can anyone help me out with that and also how do i change the text property of the page identifier from the another class.
Could you please try this? On button click event handler.
framename.Navigate(new Page1());
where Page1 is a xaml file to which you need to navigate to.
EDIT :
Your requirement could be easily implemented using MVVM model. The basic concept behind MVVM is that you can bind your data to properties in the view model class. So that you could easily control the properties of child classes from parent class and vice versa using instances of view model classes.
Could you try this for the time being?
((MainWindow)System.Windows.Application.Current.MainWindow).Framename.Navigate(new Page());
Also try this, to make the component as public.
For access controls in other WPF windows, you have to declare that control as a public, the default declaration of controls in WPF is public, and you can specify it with this code:
<TextBox x:Name="textBox1" x:FieldModifier="public" />
And after than you can search in all active windows in application to find than windows have that control like this:
foreach (Window window in Application.Current.Windows)
{
if (window.GetType() == typeof(Window1))
{
(window as Window1).textBox1.Text = "I change it from another windows";
}
}
Related
I've an UserControl, which basically looks like this:
You guessed, the goal is to allow the user to choose a file/folder when clicking on Browseand then display the file path in the TextBox.
I started my first fully MVVM application(Using Prism+Unity), and I have in fact an IDialogService which allows me to show a MessageBox, but also display some OpenFileDialog and SaveFileDialog.
I would like to use the implementation provided for this IDialogService in order to display to the user my dialog box once the Browse command is executed.
Since the UserControl isn't built with Unity, how to request the implementation ?
If I understand you correctly, your UserControl needs to get hold of the Unity container you're using, one way or another. If you're instantiating the UserControl yourself, you can consider adding it as a constructor parameter; if it's instantiated by the framework you could consider a Container property or a setter method. Or you could go with the container as a singleton.
Either way, assuming your UserControl has a field like so...
IUnityContainer container;
...and that you've managed to point it to the container you're using, you should be able to resolve your service the normal way:
IDialogService service = container.Resolve<IDialogService>();
service.OpenFileDialog(...);
I've created an application with many UserControls and now I need to call some function from other UserControl ViewModel, my question is how to build the ViewModels hierarchy to have an access for doing this? What is the best design pattern for this?
Let say I have:
MainUserControl which contains
UserControl_1 and ViewModel_1
UserControl_1_1 and ViewModel_1_1
UserControl_2 and ViewModel_2
so now from UserControl_1_1 I need to call some function from ViewModel_2
Any Example how to init all UserControl's DataCOntexts?
UserControl_1_1 is my TaskDetail
UserControl_2 is my Library
in my TaskDetail I have an attachment and after navigate button clicking I need to navigate to my Library usercontrol and select current attachment
For cross view model communication look into the Event Aggregator pattern (a version of Pub/Sub).
Each viewmodel takes a reference to the event aggregator and then viewmodel1 can publish a message that viewmodel2 acts on.
i faced with some problems when designing architecture of my extensible programm.
I'm using MEF, MMVM Light Toolkit and AvalonDock.
The first problem is how display view for some ViewModel imported from another assembly using MEF.
To solve it, i'm exporting ResourceDictionary where i'm defining DataTemplate's for views declared in this assembly.
Dictionary:
<ResourceDictionary
...>
<DataTemplate DataType="viewmodels:MyViewModel">
<views:MyViewForViewModel/>
</DataTemplate>
</ResourceDictionary>
And in constructor of MainWindow i'm importing all ResourceDictionaries and merging them with MainWidow.ResourceDictionary.
Is it good? It's also possible to specify 'scope' of ResourceDictionary to import it not to MainWindow, but to Application for example.
The second problem is ICommands and CommandBindings.
To populate Menu i'm exporting 'MenuItems' where i'm defining ICommand, Text and other stuff, but i don't know how to export CommandBinding, should i use RelayCommand for cases when i can't create CommandBinding?
The third problem is dialogs.
I found great article Showing Dialogs When Using the MVVM Pattern and easily adapt it to MEF. But, for example, I have an IDatabaseService which don't have any View.
The Workspace, main ViewModel, storing instance of IDatabaseService and creating menu item: Connect to Database. Using IDialogService Workspace opening some imported IConnectToDbDialog so Workspace don't know anything about it. When dialog closed, the SqlConnectionString should be passed to IDatabaseService.
So who must pass this SqlConnectionString, IConnectToDbDialog or Workspace.
The fourth problem is how to communicate with IDatabaseService correctly.
For example. In some View i have Button: 'Create Item In Database'. And how should i call IDatabaseService method CreateItem(ElementType elementType) when button clicked?
The problem, that there are a lot of buttons which create Items with different ElementType in database, so, i think, it's right to create some ICommand with parametr and create only one handler for this command which will invoke some method in IDatabaseService. But i don't know how.
The other solution is to send messages to IDatabaseService from ViewModel to create item.
which way better?
Try to answer your questions.
It is good. You can merge either on XAML or code behind but I prefer XAML. You can put it on MainWindow.Xaml, which is in scope of main window or on App.Xaml, which is in application scope.
I did not export views before. In my opinion, if you put CommandBindings under Menu, it does not matter when it is exported then imported if the event handler in the scope of imported environment.
It depends. Theoretically you can put the service call in either owner's view model or dialog's view model. If your dialog have a create/submit button, for instance, and you expect the dialog keeps alive until submission is successful, then put it in dialog's view model so that you can keep it open when you handle exceptions. if you do not need the dialog keeps open, then you can put the logic in owner's view model after dialog is closed.
Command is better. Considering the view model gets IDatabaseService object from IoC container, You might have one ICommand property that accepts ElementType parameter or a paramerter can map to ElementType. In the execute method you call CreateItem passing the parameter directly or from mapper. On you XAML, you put type in the command binding. Does it make sense?
Hope it can help.
I'm creating a silverlight user control that I should be able to drag and drop via blend. But this control needs to accept a map that is already on the page.
For eg.
Main.xaml contains a map control.
MapEditor.xaml contains buttons and other controls. In the .cs file, it needs to access a map control (the one in Main.xaml).
How do I go about getting this done?
I was thinking about adding a parameter in the contructor for MapEditor but how would I pass in the map as a parameter in design mode?
Thanks.
ps. I'm going to break out this control into a silverlight library so it could be used in multiple projects later.
You don't want to be giving your control a parameterised constructor, XAML will only construct types using their default constructor.
Simple Approach
The easiest approach would be to add DependencyProperty to your control to which you would assign the Map control (I'll use the type name MyMap in this example):-
public MyMap Map
{
get { return (MyMap)GetValue(MapProperty); }
set { SetValue(MapProperty, value); }
}
public static DependencyPropery MapProperty = new DependencyProperty("Map",
typeof(MyMap), typeof(MapEditor), new PropertyMetaData(null));
Now in Blend the Map property will appear in the Miscellaneous category in the Properties tab. You can then use the "Element Property" tab of the "Create Data Binding" to select the Map control to which it should bind.
Hard Core Approach
That said I would be inclined to build a proper customisable control following these guidelines Creating a New Control by Creating a ControlTemplate. With the addition that I would extend the ContentControl base class and include a ContentPresenter at the heart of the template. The control would make the assumption that the child control is a MyMap control.
This approach allows the entire appearance of the MapEditor control to be styled in Blend and it allows the Map control that is to be "edited" to be drap-drop onto the MapEditor as a child control.
Trying to implement what I thought was a simple concept. I have a user control (view) bound to a view model which provides a list of data. I have added toggle buttons to the usercontrol and would like to allow the user to use these toggle buttons to switch out which template is used to show the data. All of the templates used for the data work, and they are very different from one another so it's not just simple changes to a single template. I'd like to get this as much in XAML as possible.
Here's what I have now:
Where the data appears I have <UserControl Template="{StaticResource ListSwitchingControlTemplate}" />
In that control template I have all "sub templates" - really it's just all 3 representations with their visibility set to Collapsed. Then I use a data trigger on that control template to show the currently selected view. This works, but I noticed that all 3 representations get bound - they each act like they are active (and they are I guess).
I'd rather be able to truly switch the template at run time. I tried converting the containing user control to use a ContentTemplate for itself, but that just messes up all of the binding I have elsewhere. If only UserControls could use DataTriggers I'd be ok.
Any suggestions on how to cleanly go about getting this behavior. I have an idea that I'm just missing something simple.
Thanks,
Dave
you could do it via code?
http://www.switchonthecode.com/tutorials/wpf-tutorial-how-to-use-a-datatemplateselector ???
http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/4fd42590-8375-46d0-b7bc-6c217df0f0ba/
http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/dbbbb5d6-ab03-49a0-9e42-686fd41e0714
One way to do this would be to use a DataTemplateSelector.
Basically, you create a class that inherits from DataTemplateSelector and override its SelectTemplate virtual function. The return value from the function is the DataTemplate you want to use and in that function you have access to the object and its properties, which you can use to decide which template to select.
There is an example on MSDN here:
http://msdn.microsoft.com/en-us/library/system.windows.controls.datatemplateselector.aspx