In Silverlight I've a page with some controls and a listbox.
I'm using MVVM and the dataContext of the listbox is defined like this. In my model I have a property ProductCommand and this ProductCommand object contains a list of product named Products.
My listbox is in a grid with the datacontext defined as the ProductCommand property. and the databinding for the listbox is set to the Products (Binding="{Product, Mode=twoWay}").
In my model class I also have a selectedProduct property, and I want to bound it to the SelectedItem property of the listbox.
How can I do that?
I have had similar problems I found this blog article by Dan Wahlin on a Data Context Proxy very helpful.
Of course in Silverlight 5 ancestor binding will also provide you a means to solve this issue.
Related
I have used exprssion blend4 edit itemcontainerstyle and increased 3 textblocks in item. NOW, i want to bind the 3 textblocks to a class. The class has 3 different properties. For example,i has a student class,student has name ,age,and major.I want to bind whole school students to listbox and each textblocks display specific information.
You should read at least the MSDN Data Binding Overview. It provides the necessary basic knowledge about data binding in WPF.
I've got a TabControl in my WPF application. The TabControl's ItemsSource is bound to an ObservableCollction of view objects. It uses a DataTemplate to populate the visual tree for the tabs from the Items in the collection.
I need to be select the current tabs in the conde-behind in response to actions the user takes on another screen in the application. When I iterate over the items in the TabControl's Items collection, I get the instances of my view models.
How do I access the actual TabItems and iterate over them, then select the one I want?
Tony
If you're using a MVVM approach you should bind your TabControl's SelectedItem property to the same object that holds your ObservableCollection of TabItems (the ViewModel). When you need to change the current tab set the SelectedItem property to the correct TabItem in the ObservableCollection.
I implemented some generic CustomControls in WPF, for instance an AutoCompleteTextBox.
Now, I'd like to implement a generic ViewModel library, in order to perform the databind of these controls.
Now I defined one attached property named CDataSource, that specifies the source of the data to bind within the control.
My question is : Is it possible, that the CustomControl passes to the ViewModel the CDataSource value? In this way the ViewModel may populate the control on the basis of the CDataSource property.
Thanks in advance
This seems like a strange request to me. You don't want any dependency on your view model from within your custom control. Instead, you would normally have a dependency property on your custom control which is the ItemsSource, and then you would set the value of this from your view in XAML.
This is how the AutoCompleteBox included in the WPF Toolkit operates.
I have a tab control where each TabItem is a UserControl. I'd like to hold the UserControls in the TabControl's ItemsSource. Does ItemsSource list go in the Window's ViewModel? If so, I feel like it's breaking MVVM since the ViewModel would now have GUI controls within it. Or do I put this list in the codebehind of the window that holds the tab control?
Any suggestions would be great!
With tab controls, more often than not the individual tabs are created statically in XAML rather than at run time by data binding. However there is no reason why you shouldn't do this. If you have a collection of views, they should definitely be stored in a view.
Bear in mind that you could also bind the ItemsSource to a list of ViewModels objects and WPF will generate a view for you with the ItemTemplate, with the ViewModel object set as the DataContext. This collection of ViewModels should be stored in a view model, although at some point a view model will obviously have to be stored in a view.
This can most likely be done in a number of ways, all which are up for debate on how "MVVM-friendly" they are.
My setup looks like the following.
My Main window has a DataContext bound to a MainWindowViewModel which contains an property
public ObservableCollection<Workspace> WorkspaceCollection{get;set;}
MainWindow has a TabControl which ItemsSource is bound to WorkspaceCollection
Workspace are all viewmodels and are bound to different views/usercontrols via DataTemplates
You might have a look at the Write sample application of the WPF Application Framework (WAF). It has a TabControl where each TabItem is a UserControl and it does this by applying the MVVM pattern.
Here's what I've done.
I created an interface that all of my controls implement, IMyAppControl, which has some information such as Title, Description, other metadata.
My Main Window has an ObservableCollection that the tab ItemsSource binds to.
HI Can any one suggest me how bind viewmodel to a usercontrol..
Also please share different way of doing that..
I have added viewmodel and view into my xaml file in namespace and in the user control resource tag.. i have defined a data template with data type as the viewmodel wh i have wrote.. inside that i have added my view (i mean the same usercontrol ih which im editing now is it possible -- please let me know).. I have used content control with content={Binding}.. and contenttemplate as a datatemplate.. in that i have reffered the property which i want to bind from viewmodel).. but its not binding as such..
My query is different ways of binding viewmodel to view in UserControlLibrary Project ?
Sdry's right, you can also set the DataContext property of your view to your ViewModel.
Also, here's a WPF databinding cheat sheet that will likely come in handy: http://www.nbdtech.com/Free/WpfBinding.pdf
Set the datacontext of your view, with an instance of your viewmodel. Throughout your view you can then bind to the properties of your viewmodel with "Path" in the binding.