I am pretty new to WPF, and in order to get some knowledge I decided to make a very simple UML modeling program, that basically offers the possibility to put some classes onto a canvas, connect them and move them around.
Now to the question:
I have been thinking about letting the classes I put on the canvas being a userControl I design. In my mind it would be something like a Grid, with some textboxes to represent properties, attributes and so on. The actual question is then, is my idea possible, or should I go with something completely different? My concern right now is how to implement the grid such that it can expand (add a row) under the right heading (Attribute/property..) when I want it to, and not be expanded to a maximum from the beginning.
I hope you can understand my question, and give me an idea to whether I should continue to implement it how I thought about, or do it using some other method.
You may wish to consider a ListView control, perhaps with an Expander, something like this:
<Canvas>
<Expander Header="Stuff"
MaxHeight="900"
Canvas.Left="202"
Canvas.Top="110">
<ListView Name="MyListView">
<ListView.ContextMenu>
<ContextMenu>
<MenuItem Header="Add new thing"
Click="MenuItem_Click" />
</ContextMenu>
</ListView.ContextMenu>
<ListViewItem>
<StackPanel Orientation="Horizontal">
<Label>Name</Label>
<TextBox Text="Value" />
</StackPanel>
</ListViewItem>
<ListViewItem>Item two</ListViewItem>
<ListViewItem>Item three</ListViewItem>
</ListView>
</Expander>
</Canvas>
This will size as needed up to the max given. The list view items could contain any sort of content (not just text) as you can see above. You will want to learn a bit about Style and Control templates. WPF has IMHO a rather steep learning curve but there are a lot of learning resources on the web. Good luck.
In response to your comment, I'm adding additional information.
Anything you can do in XAML you can do in code behind (mostly XAML just calls framework objects). In this case I've added a context menu to the ListView control. This menu contains one item "Add new thing". There is a Click event for this item which is bound to the MenuItem_Click method in the code behind. I then added this method to the code:
void MenuItem_Click(object sender, RoutedEventArgs e) {
var lvi = new ListViewItem();
lvi.Content = String.Format("New thing {0}", DateTime.Now);
MyListView.Items.Add(lvi);
}
Now if you right click in the ListView you will see the "Add new thing" menu selection, left clicking it adds a new ListViewItem into the ListView (programmatically).
Related
I'm trying to find the best solution for a TabControl that both support a close button on each TabItem, and always show a "new tab button" as the last tab.
I've found some half working solutions, but i think that was for MVVM, that I'm not using. Enough to try to understand WPF =)
This is the best solution I've found so far:
http://www.codeproject.com/Articles/493538/Add-Remove-Tabs-Dynamically-in-WPF
A solution that i actually understand. But the problem is that it is using the ItemsSource, and i don't want that. I want to bind the ItemsSource to my own collection without having to have special things in that collection to handle the new tab button.
I've been search for days now but cant find a good solution.
And I'm really new to WPF, otherwise i could probably have adapted the half done solutions I've found, or make them complete. But unfortunately that is way out of my league for now.
Any help appreciated.
I have an open source library which supports MVVM and allows extra content, such as a button to be added into the tab strip. It is sports Chrome style tabs which can tear off.
http://dragablz.net
This is bit of a dirty way to achieve the Add (+) button placed next to the last TabItem without much work. You already know how to place a Delete button next to the TabItem caption so I've not included that logic here.
Basically the logic in this solution is
To bind ItemsSource property to your own collection as well as
the Add TabItem using a CompositeCollection.
Disable selection of
the Add(+) TabItem and instead perform an action to load a new tab when it
is clicked/selected.
XAML bit
<TextBlock x:Name="HiddenItemWithDataContext" Visibility="Collapsed" />
<TabControl x:Name="Tab1" SelectionChanged="Tab1_SelectionChanged" >
<TabControl.ItemsSource>
<CompositeCollection>
<CollectionContainer Collection="{Binding DataContext.MyList, Source={x:Reference HiddenItemWithDataContext}}" />
<TabItem Height="0" Width="0" />
<TabItem Header="+" x:Name="AddTabButton"/>
</CompositeCollection>
</TabControl.ItemsSource>
</TabControl>
The code behind
private void Tab1_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (e.AddedItems.Contains(AddTabButton))
{
//Logic for adding a new item to the bound collection goes here.
string newItem = "Item " + (MyList.Count + 1);
MyList.Add(newItem);
e.Handled = true;
Dispatcher.BeginInvoke(new Action(() => Tab1.SelectedItem = newItem));
}
}
You could make a converter which appends the Add tab. This way the collection of tabs in you viewmodel will only contain the real tabs.
The problem is then how to know when the Add tab is selected. You could make a TabItem behavior which executes a command when the tab is selected. Incidentally I recommended this for another question just recently, so you can take the code from there: TabItem selected behavior
While I don't actually have the coded solution, I can give some insight on what is most likely the appropriate way to handle this in a WPF/MVVM pattern.
Firstly, if we break down the request it is as follows:
You have a sequence of elements that you want to display.
You want the user to be able to remove an individual element from the sequence.
You want the user to be able to add a new element to the sequence.
Additionally, since you are attempting to use a TabControl, you are also looking to get the behavior that a Selector control provides (element selection), as well as an area to display the element (content) which is selected.
So, if we stick to these behaviors you'll be fine, since the user interface controls can be customized in terms of look and feel.
Of course, the best control for this is the TabControl, which are you already trying to use. If we use this control, it satisfies the first item.
<TabControl ItemsSource="{Binding Path=Customers}" />
Afterwards, you can customize each element, in your case you want to add a Button to each element which will execute a command to remove that element from the sequence. This will satisfy the second item.
<TabControl ...>
<TabControl.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Path=CustomerId}" />
<Button Command="{Binding Path=RemoveItemCommand, Mode=OneTime,
RelativeSource={RelativeSource FindAncestor,
AncestorType={x:Type TabControl}}"
CommandParameter="{Binding}" />
</StackPanel>
</DataTemplate>
<TabControl.ItemTemplate>
</TabControl>
The last part is a bit more difficult, and will require you to actually have to create a custom control that inherits from the TabControl class, add an ICommand DependencyProperty, and customize the control template so that it not only displays the TabPanel, but right next to it also displays a Button which handles the DependencyProperty you just created (the look and feel of the button will have to be customized as well). Doing all of this will allow you to display your own version of a TabControl which has a faux TabItem, which of course is your "Add" button. This is far far far easier said than done, and I wish you luck. Just remember that the TabPanel wraps onto multiple rows and can go both horizontally or vertically. Basically, this last part is not easy at all.
I am trying to find a best or common practice for creating a table of buttons from a database list.
For my use I am creating more of a Point of Sale type screen. Where I want the categories to load as buttons on the entry screen. The buttons would have a simple task of showing a screen of more dynamically created buttons of the actual items. Those buttons would add the items to, lets call it, a ticket.
The solutions I found were few. I am also trying to code this so others can pick it up fairly quickly. I am extremely rusty and only code once in a while. So I try to follow common ways of doing it. I had some ideas but the code becomes hard to read, mostly because of me.
I saw the below link but was not sure if a ListBox was a good container for this.
Dynamic filling WrapPanel buttons from DB, setting the event handlers
I am sure a wrappenel is what I would have to use, but do I put it in a container or use it directly. Do I put it in Xaml or code it all, for issues like spacing between buttons? I think I am overthinking it and need to skip for a little bit.
Thank you,
It sounds like you want an ItemsControl, bound to your categories, with a WrapPanel as the ItemsPanel. The Button would go in the ItemTemplate.
<ItemsControl ItemsSource="{Binding CategoriesFromDatabase}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<Button Content="{Binding}"
Command="{Binding RelativeSource={RelativeSource AncestorType=ItemsControl},Path=DataContext.AddToTicketCommand}"
CommandParameter="{Binding}" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
Here I assumed that your view model has properties "CategoriesFromDatabase" (an IEnumerable that you populate from the database), and an ICommand "AddtoTicketCommand" which takes the category as a parameter.
All,
I have searched extensively for the solution here but I have a feeling my problem stems from a basic lack of knowledge about WPF. I am new to it and have thus far hacked and Googled my way through as best I can.
Basically, I have a Ribbon dynamically interacting with a TabControl. The Ribbon tabs select a category of items, the MenuItems in the RibbonGroups then choose an item within the category. Upon clicking an item, the tabs on the TabControl need to dynamically change. Whether that is just the Headers, the tabs themselves, or the entire TabControl is fine with me. Thus far, upon clicking a MenuItem on the inside one of the RibbonGroups, I attempt to just set the Header text equal to "blah" for each tab on the TabControl. Then the Header object throws a null pointer. This is what happens whether I set the Header, the Tabs, or the TabControl itself.
Why?!?!?!?
...and how in the world do I fix it???
Thanks!
WPF is designed with data/UI separation in mind. One of the reasons you're having trouble finding a solution is because what you're trying to do is a no-no; instead of programmatically changing the UI's header text, you should be changing the underlying data instead, and allowing the WPF plumbing to update how the data is displayed.
A WPF tab control can literally contain any type of object; you could fill it with integers or strings or FooBars or whatever. There's no guarantee that any of these objects will define a Header property, and it's up to the developer to configure data bindings or templates which instruct the TabControl just how a FooBar or a whatever should be displayed.
In an ideal WPF application which adheres to the MVVM design pattern, you might have your TabControl bound to a collection of view models which each define a HeaderText property. Your view models would implement the INotifyPropertyChanged interface so that when the HeaderText property was changed on the view model then the UI would get updated.
Having said all that, if you've got an existing application it may be unrealistic to rewrite it from scratch using a different design pattern, and MVVM is not easily added on to an existing code base. If you're working with simple Designer generated UI without using any data binding, then the following code does what you ask. Sometimes.
foreach(TabItem item in tabControl.Items)
item.Header = "blah";
... but as I said before, there's no guarantee that a WPF TabControl's Items collection will contain items of type TabItem, so this code is not safe.
While RogerN's answer is probably a better answer, here is a code sample that changes the text that appears on a tab:
XAML:
<Grid>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<TabControl Name="MyTabControl">
<TabItem Header="Tab One">
<TextBlock Text="This is tab #1." />
</TabItem>
<TabItem Header="Tab Two">
<TextBlock Text="This is tab #2." />
</TabItem>
<TabItem Header="Tab Three">
<TextBlock Text="This is tab #3." />
</TabItem>
</TabControl>
<Button Grid.Row="1" Content="Change Tab" Name="ChangeButton" Click="ChangeButton_Click" />
</Grid>
Code behind:
public partial class MainWindow : Window {
public MainWindow() {
InitializeComponent();
}
private void ChangeButton_Click(object sender, RoutedEventArgs e) {
((TabItem)MyTabControl.Items[0]).Header = "Changed!";
}
}
Try binding it to a list in the code like so:
private List<TabItem> TabItems = new List<TabItem>()
{
"Item1",
"Item2",
"Item3"
};
tabcontrol1.ItemSource = TabItems;
Then rebind it any time you want to change the items in the tabcontrol. This way you can dynamically change names and add more tab items. In doing this you'll have to programmatically add controls using the TabItem.Content property.
I have the following code that adds a context menu to a textbox on the UI. The user is supposed to be able to bring up the context menu and select a new units to be used. So the method CurrentUnits in my view model is bound to the textbox. I want a context menu populated by all the potential units. So the method Units in my view model returns a string[] of unit options; such as inches, cm, feet, meters, etc. When the user selects one the method NewUnits_Click is invoked. All works fine, however the contextmenu does not go away when the user selects a menu option. Pressing somewhere else on the screen like the application menu bar will then clear it. Has anyone else seen this problem, or see something wrong with the code below. It seems to have something to do with the ItemTemplate/DataTemplate I have, as creating an set of menu items by hand works fine.
<TextBlock Width="100" Text="{Binding CurrentUnits}" TextAlignment="Right">
<toolkit:ContextMenuService.ContextMenu>
<toolkit:ContextMenu ItemsSource="{Binding Units}">
<toolkit:ContextMenu.ItemTemplate>
<DataTemplate>
<toolkit:MenuItem Header="{Binding}" Click="NewUnits_Click" />
</DataTemplate>
</toolkit:ContextMenu.ItemTemplate>
</toolkit:ContextMenu>
</toolkit:ContextMenuService.ContextMenu>
</TextBlock>
If you aren't using MVVM when working with WPF, I highly suggest you to start doing so. And even if you are not, I suggest that instead of binding to Click you instead bind on the Command property which wants something that implements ICommand. I think that the behavior you are getting is intended, buttons and menu items in WPF are intended to bind to Commands, it's not just WinForms 2.0.
Another solution would be to hide the Context menu in the code-behind. Perhaps this resource will help you in achieving that.
I'm looking for a way to create an application layout for a little tool that looks like the ESET Antivirus UI:
I thought, that I take a TabControl and do a complete Restyling on this whole thing. I created a basic tab layout:
<Grid Background="White" Grid.Row="1" >
<TabControl TabStripPlacement="Left">
<TabItem Header="Dashboard">
<Grid>
</Grid>
</TabItem>
<TabItem Header="Projects">
<Grid>
</Grid>
</TabItem>
<TabItem Header="Settings">
<Grid>
</Grid>
</TabItem>
<TabItem Header="Help & Info">
<Grid>
</Grid>
</TabItem>
</TabControl>
</Grid>
However, I don't have the slightest clue how to get the tabs the way I'd like them to be. I tried a lot with Blend to get the Tabs look the image above, but I don't get it. The triangle would be a nice to have, but the highlighting should be adapted.
Any advice?
Whenever you are having trouble with trying to make WPF UI elements look exactly the way you want, you should go find the default <style> XAML from microsoft and try modifying that directly in your project until you get the desired result.
In case that wasn't clear, you you need to do is follow the links below, copy the style from the pages and put them into the Resources section of your window (or App.xaml, its really up to you). Then fiddle with them until you get it to look the way you want.
The two styles you'll need to play with are TabControl and TabItem
I'd think to a MVVM approach, instead.
Before all, shape the model of the data, as well as the business layer (commands, functions, etc.).
Then, you can "wear" your model (by leveraging a ViewModel) with a ListBox, for the left selector, and a simple ContentControl for the main part.
The selected item of the ListBox should be fed into the content of the body, and a DataTemplateSelector (for instance) will choose the proper visual fragment.
It's just a suggestion. Personally, I've found a bit tricky the TabControl and I seldom use it.
Cheers
An old trick is to have 2 different sets of images - one for clicked and one for passive (maybe one for mouseover) but clicked image will have the triangle in it.
This uses static images for buttons, which is very easy to use, but hard to modify on the fly.