The code example in this tutorial demos how to add list box items, add items to a ListBox, remove items from a ListBox, and bind a ListBox to a data source. Download attached project and open in Visual Studio and run it. Several parts of the XAML file may be commented. Uncomment the part you would like to run. The Width and Height properties represent the width and the height of a ListBox.
The Name property represents the name of the control, which is a unique identifier of a control. The Margin property tells the location of a ListBox on the parent control.
The HorizontalAlignment and VerticalAlignment properties are used to set horizontal and vertical alignments. The following code snippet sets the name, height, and width of a ListBox control. The code also sets horizontal alignment to left and vertical alignment to top.
The following code example adds a collection of items to a ListBox control. We can add items to a ListBox from the code. Let's change our UI and add a TextBox and a button control to the page.
Add method. The following code adds TextBox contents to the ListBox items. We can use ListBox. Remove or ListBox. RemoveAt method to delete an item from the collection of items in the ListBox.
The RemoveAt method takes the index of the item in the collection. Now, we modify our application and add a new button called Delete Item. The XAML code for this button looks like below.It lets you make a series of items available for selection in a list, with multiple items visible and selectable at the same time. Within this relatively simple framework, the WPF ListBox provides considerable flexibility, making it a remarkably versatile tool.
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At its most basic, the ListBox simply lists a series of text items, one above the other. When the user clicks on an item, it is highlighted, and the SelectedItem property returns that item. In the above sample, the item with the long name will fit the box. If you make the box much narrower by setting the width to something lower than pixelsor the name of the item longer, the Basic ListBox window will have scrollbars.
In order for the WPF ListBox control to be useful, of course, you need to be able to do something with the selected item. The simple way to do this is with the SelectedItem property. Then we add the TextBox, bind it to the ListBox using the name that we just gave it and tell it to display the Content the selected text itself of SelectedItem. Now when you click on an item, the text will appear in the TextBox.
Of course, as a well-trained. The options for SelectionMode are Extended which allows multiple selections using the Shift and Ctrl keysMultiple which allows multiple selections without holding down any keyand Single the default, which does not allow multiple selections. With the Extended or Multiple modes, you can either use the SelectedItem property to return the first item from those that are currently selected, or use the SelectedItems property to return all of the items currently selected in the form of a collection of the type System.
Since SelectedItems is a collection, it is considerably more complex than the SelectedItem property. They key properties to keep in mind when using SelectedItems with a ListBox are Count, which returns the number of elements, and Item, which returns the element at a specified index.
The ListBox control is part of the ItemsControl class of controls, and it inherits some important properties from ItemsControl. Among these are text formatting, and the ability to list items besides simple text strings. There are times when plain text is nice, but there are also times when you will want to format it:. Needless to say, the output of this example is not a thing of beauty, but it does show what you can do with text formatting in a ListBox.
Note that some features such as FontStretch do not apply to all fonts. A ListBox control can list graphics as well as text. In practice, you might use a StackPanel control with Horizontal orientation to place the image and accompanying text on the same line, as well as setting the size of the image.We have a list of items in an ObservableCollection so that the View updates if we modify the content of the collection.
We also have a placeholder for some command that will operate on the selected items. For completeness, here is the implementation of a basic ViewModel base class and a simple ICommand implementation. Alas, this is not currently possible. If we only care about setting the selected items from the View and operating on it when a command it executed, we can do this relatively simply.
First we need to give the ListBox a name. And then we can add a command parameter that points at the ListBox SelectedItems property. The property is an IList non-generic containing ItemPresenter references. Now our command will receive the list of selected ItemPresenter objects as a parameter and we can do as we wish with them.
Firstly, we need to add a property to ItemPresenter to store the selected state of the item. And then we have to find a way of binding that property to the View. The easiest way to do this is to create a style for a ListBoxItem and bind the IsSelected property there. There are two options available here. Firstly, we could disable virtualization on the ListBox. Posted by Mark Withall: IsSelected. Return to the main page Other me on the Internet.The WPF Way.
Some of the controls in the package require licensing and some do not. I'm passing a class item to ViewModel of type from which ListBox is bound to. The Path properties of both bindings are not specified because both controls are binding to the entire collection object.
When I make changes to the selected item, the object's Gender property is successfully updated. The WPF datagrid control supports grouping rows by their column values — making complicated tables easier to read — and this can be extended with expand and collapse functionality. But I want to use the DynamicResource extension, is it possible? Edit based on your comment.
You can try this example solution and experiment with the properties. Those templates using system brushed in order to paint background colors. A lesser-known feature of Snoop is its ability to identify data binding problems. We then specify the Loaded and SelectionChanged events. ToString for example, I would get the above dictionary. Here is a very good example on explaining the concept of binding with elementname. Then create bindings on the ListBox ItemTemplate which.
This TextBlock is bound with EmpName. This code examples are written C programming. ToString : " I have 0 selected item! Users select items in a ListBox, usually with a mouse. Text and Canvas. Now anyone who learnt WPF from a book or tutorial probably had a section all about this pair and how useful they are. How do I set ComboBox.
How to: Bind to a Collection and Display Information Based on Selection
ItemsSource property? I don't see the way to do it in code and not in XAML. As long as your entities properly implement the IEquatable interface, the bindings work properly. NET Framework 3 or higher. As a result, it displays the returned collection based on the myTaskTemplate DataTemplate.
Manually defining items for the ListBox makes for a fine first example, but most of the times, your ListBox controls will be filled with items from a data source using data binding.The best way to learn a technology is to write some code with it, so I have begun working on a project of my own, which I hope to complete by end-March in spite of being working full bore on a project for a client. Once you get the logic, things flow pretty naturally. One of my recent stumbling blocks was binding with a collection.
Now that I got it to work, it seems trivial, but maybe this will help some other WPF beginner on the path to enlightenment! Imagine that your model contains a list of persons, and that you want to display two things:.
For the sake of simplicity, in this example we will not separate the Model and ViewModel.
Selecting an item in a list with WPF and M-V-VM
Our first task is to build a view to display the ModelView. This will allow the View to have access to data from the ViewModel. Note that the ViewModel knows nothing about the View. We want the ListBox to fill from the collection in the ViewModel. To do this, add the following code to the ListBox:. The second part declares that the data should be displayed calling the LastName property on the items in the list.
First part is done; if you run the app, you should see the ListBox display the names of some fine people. We could do this by setting the selection through code in the view, working with the DataContext, or firing events.
Rather, we will use binding again, and bind the SelectedItem property on the ListBox to the SelectedPerson property in the ViewModel, by adding this code:. Et voila! If you run the application, the list should be populated, and whenever you select a person in that list, it will update the selected person in the View Model, and display the first and last name in the view. Have a comment or a question? Ping me on Twitteror use the comments section! Figuring things out, one model at a time.
Now the ItemsSource works fine and I get a list of Rule objects with their names displayed in lbRules. I tried binding a textblock's text property to SelectedRule but it is always null. The error I'm seeing in the output window is: BindingExpression path error: 'SelectedRule' property not found. Can anyone help me with this binding - I can't see why it shouldn't find the SelectedRule property.
I then tried changing the textblock's text property as bellow, which works. First off, you need to implement INotifyPropertyChanged interface in your view model and raise the PropertyChanged event in the setter of the Rule property.
Otherwise no control that binds to the SelectedRule property will "know" when it has been changed. Inside the DataTemplate you're working in the context of a Rulethat's why you cannot bind to SelectedRule. Name -- there is no such property on a Rule. To bind to the original data context which is your ViewModel you can write:. Here is my full test app:. To access the parents DataContextyou can also consider using a RelativeSource in your binding:.
For me, I usually use DataContext together in order to bind two-depth property such as this question. Or, I prefer to use ElementName because it achieves bindings only with view controls. Learn more. Asked 10 years, 9 months ago. Active 2 years, 8 months ago. Viewed k times. Kjartan Oli Baylis Oli Baylis 1 1 gold badge 3 3 silver badges 4 4 bronze badges.
Active Oldest Votes. That's it, silly me, I hadn't implemented the interface on that view model. Been banging my head against a wall all morning on that one! Thanks very much for your help. Also thanks very much to everyone else, especially Yacoder, for taking the time to have a look at this. Thanks from me as well.The ListBox control is the next control in line, which adds a bit more functionality. One of the main differences is the fact that the ListBox control actually deals with selections, allowing the end-user to select one or several items from the list and automatically giving visual feedback for it.
This is as simple as it gets: We declare a ListBox control, and inside of it, we declare three ListBoxItem's, each with its own text. This gives us full control of the content as well as the text rendering, as you can see from the screenshot, where different colors have been used for each of the numbers.
From the screenshot you might also notice another difference when comparing the ItemsControl to the ListBox: By default, a border is shown around the control, making it look like an actual control instead of just output. Manually defining items for the ListBox makes for a fine first example, but most of the times, your ListBox controls will be filled with items from a data source using data binding.
By default, if you bind a list of items to the ListBox, their ToString method will be used to represent each item. This is rarely what you want, but fortunately, we can easily declare a template that will be used to render each item. Here's the example:. All the magic happens in the ItemTemplate that we have defined for the ListBox.
In there, we specify that each ListBox item should consist of a Grid, divided into two columns, with a TextBlock showing the title in the first and a ProgressBar showing the completion status in the second column. To get the values out, we use some very simple data binding, which is all explained in the data binding part of this tutorial. The default content alignment for a ListBox item is Leftwhich means that each item only takes up as much horizontal space as it needs.
The result? Well, not quite what we want:. By using the Stretch alignment, each item is stretched to take up the full amount of available space, as you can see from the previous screenshot. As mentioned, a key difference between the ItemsControl and the ListBox is that the ListBox handles and displays user selection for you.
Therefore, a lot of ListBox question revolves around somehow working with the selection. To help with some of these questions, I have created a bigger example, showing you some selection related tricks:. As you can see, I have defined a range of buttons to the right of the ListBox, to either get or manipulate the selection.
I've also changed the SelectionMode to Extendedto allow for the selection of multiple items.