A WPF Combo Box with Multiple Selection. This combo box supports multiple selection, two way binding on the Selected. Items property, and inplace editing of the Items. Source property. Introduction. The combo box that ships with WPF does not support selecting multiple items. Furthermore, the WPF list box, while it does support multiple selection, does not allow binding in XAML to the Selected. Items property. This article describes a WPF combo box that supports both. It also describes a list box, which the combo box inherits from, that supports binding to the Selected. Items property. Requirements and Design Considerations. A Bindable List Box. I'll start by describing the bindable list box, since the combo box is based on it. The name of the control is Bindable. List. Box. While System. Subscribe How do I separate out resources into multiple files in WPF? May 27, 2006 WPF allows you to define pieces of Xaml as resources, and use them in multiple. I have resource dictionary files (MenuTemplate.xaml, ButtonTemplate.xaml, etc) that I want to use in multiple separate applications. I could add them to the. Windows. Controls. List. Box has a Selected. Items dependency property, it is readonly, which means that you cannot bind to it in XAML. But what would it mean if you could? There are a number of possibilities, which makes the whole thing rather ambiguous, and which is most likely why Microsoft doesn't do it. But in the real world, it often comes up as one of those "wouldn't it be nice if" things that would work nicely for your specific situation, but just isn't supported. The reason I mention this is to highlight the importance of defining exactly what a "bindable" Selected. Items property does. Here is how I define it: When the property is set by the client, the client's store should reflect all changes. In other words, the property type is IList and it has a public setter (yes, Fx. Recently I’ve been writing a small WPF application for work where the goal is to be able to allow its users to download a single.exe file onto a server machine. I have a.ico file that is embedded as a resource (build action set to resource). I am trying to create a NotifyIcon. How can I reference my icon? notifyIcon = new. WPF Chart, Winform Webform.Net Chart, ActiveX Chart, C++ Charting Component Library, for C#, MFC, VB. Ideal for Financial, Engineering, Science, Business, Real-Time. The WPF Application Framework (WAF) is a lightweight Framework that helps you to create well structured WPF Applications. It supports you in applying a Layered. This combo box supports multiple selection, two way binding on the SelectedItems property, and inplace editing of the ItemsSource property. Cop issues a warning, but I want to be able to edit the client's list directly.) When an item is selected or unselected - either through the UI or programmatically - the underlying store should remain synchronized with the visual display. Finally, if (and only if) the underlying store supports the INotify. Collection. Changed interface, and its contents are modified from outside, the changes should be reflected in the UI. This follows a pattern used by Microsoft in other places, for example, the Items. Source property of List. Box, as we'll see below.) Another consideration is the public interface. Assuming Multi. List. Box inherits from List. Box (it does), then there are basically two choices for the selected item property: define an entirely new property to hold the bound selected items list, or keep the interface unchanged from the base class by hiding the (non virtual) List. Box. Selected. Items. Property with a "new" property of the same name. I chose the latter, because I like the idea of keeping the interface the same as the base class interface. A derived class "hides" a member of the base class when it defines a method or property or field that has the same name and signature as that base class member, and the base class member is not marked virtual. The "new" keyword is used to indicate intent to hide a base class member.) /p>. With these two decisions in place, the implementation is relatively straight forward. A Bindalbe. List. Box is simply a List. Box that has hidden the base class's Selected. Items with a property of its own. The change is transparent to the user. There is no need for any XAML, it suffices to inherit all of the default visuals from List. Box. The Multiple Selection Combo Box. It seems fairly intuitive to me how a combo box with multiple selection should behave. It should behave like a list box with multiple selection, except for the drop down. Unlike the single select Combo. Box, the drop down should remain open when a value is selected (or unselected) providing the user the opportunity to select as many items as desired without having to constantly re- open the drop down. The drop down should close when the user clicks anywhere outside the control or on the drop down button (like Combo. Box). Also, I want to support a single select mode. When in single select mode, Multi. Combo. Box should behave just like Combo. Box. One of the first questions to ask when designing a combo box that supports multiple selection is what should it inherit from? Is it a Control, a Multi. Selector, a Combo. Box or a List. Box? If Control it would still be necessary to embed one of the other three or else plan on doing a lot of extra work. Multi. Selector might be a good choice, but, for one thing, I couldn't find any examples of how to use it, and for another you would probably end up duplicating a lot of functionality found in List. Box or Combo. Box. It might seem obvious at first to inherit from Combo. Box. However, since Combo. Box doesn't allow multiple selection, you'd still have to embed a List. Box to get that functionality, and it would still be necessary to override the default Template. Multi. Combo. Box is a List. Box because with List. Box we get both multiple selection and single selection modes along with all the standard properties that List. Box and Combo. Box have in common, like Items. Source, Selected. Item, etc. This shows the power of WPF, to be making a combo box that is really a list box masquerading as a combo box. There are a couple of other features I need to implement for my use case, one that the Selected. Items property be bindable in XAML, which is why Multi. Combo. Box inherits from Bindable. List. Box and not List. Box. The other is a little more involved and outside the normal scenario for a combo box, but is needed by my application. This is the ability to add an item to the combo box's items list, while the combo box itself is open. What I need to be able to do, in the drop down itself, is click on a button that says "Create New Item" and have a text box show up where I can enter the new item's text. Then, with the click of an "Ok" button the new text is added to the Items. Source of the combo box, and is automatically selected. Here is an image taken from the sample app that comes with this article: Implementation. Implementing Bindable. List. Box entails keeping the base class's Selected. Items and the derived class's Selected. Items synchronized with each other. Other than one or two caveats, it is fairly straight forward and I don't intend to go into it here. If you are interested, please, download the code. Multi. Combo. Box inherits the ability to select multiple items and to bind to those items in XAML from Bindable. List. Box. So what is needed to make it a combo box? Mainly, it needs the drop down. There are two dependency properties that Combo. Box exposes that support the behavior of the drop down: the Is. Drop. Down. Open and Max. Drop. Down. Height dependency properties. These can be added to Multi. Combo. Box using the Add. Owner method of the Dependency. Property class (i. Combo. Box. Max. Drop. Down. Height. Add. Owner(..) which has the benefit of providing a default value. Once these two properties are in place, much of the work is done in the control's template./code /> Although Multi. Combo. Box inherits from List. Box I want it to look like a combo box, so I begin the process of creating the Template by studying the template for Combo. Box. (To do this, I use . NET reflector in conjunction with the BAMLViewer plugin, which allows me to examine the XAML of the resources defined inside the . NET assembly Presentation. Framework. Aero. dll)The XAML for Multi. Combo. Box is surprisingly similar to the XAML for Combo. Box. The main difference is what is used to display the text for the selected items. In Combo. Box this is a Content. Presenter that is bound to the Selection. Box. Item property. I chose to use a Stack. Panel and populate its children property in code, when the selection changes. The other main difference, of course, is the part which houses the buttons and text box used for adding a new item to the Items. Source collection. This assembly basically just gets tacked on to the bottom of the Popup. Its Visibility property is Collapsed by default, then set to Visible in a Trigger, when Is. Create. New. Enabled becomes true. Showing and hiding the drop down (a Popup work the same here as with a Combo. Box. Both the toggle button and the popup are bound to the control's Is. Drop. Down. Open property. When the toggle button is checked, Is. Drop. Down. Open becomes true, which causes the popup to open. And vice- versa. I had to use Event. Triggers with Story. Board animation for showing and hiding the enter new item assembly when the buttons are clicked. This gets a little messy, but it is possible to set Visibility in an event trigger, using a Discrete. Object. Key. Frame inside an Object. Animation. Using. Key. Frames collection. Here is the complete template: < Control. Templatex: Key="Multi. Select. Combo. Box. Read. Only. Template"Target. Type="{x: Type local: Multi. Combo. Box}"> < Grid> < Toggle. Button. Name="toggle. Button"Is. Tab. Stop="False"Background="{Template. Binding Background}"Border. Brush="{Template. Binding Border. Brush}"Border. Thickness="{Template. Binding Border. Thickness}"Template="{Static. Resource Multi. Select. Combo. Box. Toggle. Button. Template}"Is. Checked="{Binding Relative. Source=. {Relative. Source Templated. Parent}. Path=Is. Drop. Down. Open, Mode=Two. Way}"> < Stack. Panel. Name="PART_label. Content. Panel"Is. Hit. Test. Visible="False"Margin="4,0,5,0"Orientation="Horizontal"Horizontal. Alignment="{Template. Binding Horizontal. Content. Alignment}"/> < /Toggle. Button> < Popup. Name="PART_popup"Stays. Open="False"Allows. Transparency="True"Placement="Bottom"Is. Open="{Binding Relative. Source={Relative. Source Templated. Parent}. Path=Is. Drop. Down. Open}"Popup. Animation="Slide"> < theme: System. Drop. Shadow. Chrome. Name="Shadow"Color="Transparent"Max. Height="{Template. Binding Max. Drop. Down. Height}"Min. Width="{Template. Binding Actual. Width}"> < Border. Border. Brush="{Template. Binding Border. Brush}"Border. Thickness="{Template. Binding Border. Thickness}"Background="{Template. Binding Background}"> < Stack. Panel> < Scroll. Viewer. Max. Height="{Template. Binding Max. Drop. Down. Height}"> < Items. Presenter. Margin="{Template.
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