I have set up a ListView to manage tabs on my app. So users can drag and drop tabs to new instances of the app and reorder tabs. All goes great until I set up a ControlTemplate for the Itens at the ListView.
I used ControlTemplate because when I add a ListView.ItemTemplate directly it won`t work (it does not affect the listview item). So before adding a new item I use this:
tab.Template = (ControlTemplate)this.Resources["listViewItemTemplate"];
So the tabs is looking great, but all the functions that used to work (like drag and drop) isn't working anymore. When I remove the ControlTemplate the ListView show only one little string.
This is what is happening
My ListView Code:
<ListView x:Name="TabsListView"
CanDragItems="True"
AllowDrop="True"
DragEnter="TabsListView_DragEnter"
Drop="TabsListView_Drop"
ScrollViewer.VerticalScrollBarVisibility="Disabled
CanReorderItems="True"
DragItemsStarting="TabsListView_DragItemsStarting"
ItemClick="TabsListView_ItemClick" >
I know for sure that the issue isn't on the drag and drop method.
To create a new item I just use Add. Of course I checked every single item inside ControlTemplate to know that it is not blocking anything.
The control template is:
<ControlTemplate x:Key="listViewItemTemplate" >
<ListViewItem>
<Grid Tapped="Grid_Tapped" Width="180" Margin="-12,-12,-12,0">
<TextBlock Text="{Binding Name}" Margin="5,6,0,0"></TextBlock>
</Grid>
</ListViewItem>
</ControlTemplate>
The reason is that you are using ControlTemplate and embedding a ListViewItem in there. ListViewItems are created automatically by the control to contain the items, and ItemTemplate is a template of the contents of this container. So it should look like this:
<DataTemplate x:Key="listViewItemTemplate" >
<Grid Tapped="Grid_Tapped" Width="180" Margin="-12,-12,-12,0">
<TextBlock Text="{Binding Name}" Margin="5,6,0,0"></TextBlock>
</Grid>
</ControlTemplate>
<ListView ...
ItemTemplate="{ThemeResource listViewItemTemplate}">
...
</ListView>
Furthermore, if you want to style the ListViewItem (the container), you can create a style with TargetType="ListViewItem" and set it as ListView.ItemContainerStyle.
<Style TargetType="ListViewItem" x:Key="TabListViewItemContainerStyle">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListViewItem">
<Grid x:Name="ContentBorder">
... some template with ContentPresenter:
<ContentPresenter x:Name="ContentPresenter" ... />
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<ListView ...
ItemContainerStyle="{StaticResource TabListViewItemContainerStyle}">
...
</ListView>
You can find the default style in: C:\Program Files (x86)\Windows Kits\10\DesignTime\CommonConfiguration\Neutral\UAP\10.0.15063.0\Generic
Update
I have checked the code and found the problem. What you are actually doing is adding ListViewItems directly in code:
ListViewItem tab = new ListViewItem();
DataModel model = new DataModel();
model.Name = $"NewTab {counter}";
tab.DataContext = model;
tab.Content = model.ToString();
TabsListView.Items.Add(tab);
Unfortunately this does not work, because when ListView sees an item that is of type ListViewItem, it just adds it to the list, but ItemTemplate doesn't apply to it, because that is applied only when the items are not UIElement but rather a custom class. If you use DataModel directly, ItemTemplate will be applied as expected:
DataModel model = new DataModel();
model.Name = $"NewTab {counter}";
TabsListView.Items.Add(model);
ListView encounters DataModel, knows that just a class not a UIElement, so it internally creates a ListViewItem, applies ItemContainerStyle to it and then uses the ItemTemplate to create the UI that will be displayed inside the ListViewItem's ContentPresenter. It is better to use this approach as it gives you better decoupling as you don't have to create UI-based classes in the code-behind and you get more control (as you can change both the style of the item as well as the container).
Related
I want use a scrollbar like ComboBox in my DropDown button, the structure actually is this:
<Controls:DropDownButton Content="Nazioni" Width="120" Margin="0, 0, 20, 0"
ScrollViewer.VerticalScrollBarVisibility="Visible"
ScrollViewer.CanContentScroll="True"
ItemsSource="{Binding Countries}"
ItemTemplate="{StaticResource CombinedTemplate}"/>
but I don't see any ScrollViewer as you can see in the image below:
The drop-down of the DropDownButton already contains a ScrollViewer (it is named "SubMenuScrollViewer"), so scrolling through its items is supported out-of-the-box. The thing is, that particular ScrollViewer is styled differently than a default ScrollViewer - assuming we're talking about vertical scrolling, it has two buttons above and below the list, responsible for scrolling up and down respectively, as shown below:
So your best bet is to make that particular ScrollViewer use the default style rather than a custom one. By inspecting the MahApps.Metro source code we can see that the ScrollViewer in question is wired to use a dynamic resource with a key value of {ComponentResourceKey ResourceId=MenuScrollViewer, TypeInTargetAssembly={x:Type FrameworkElement}}. So what you need to do is to supply a default style with that key for that control:
<Controls:DropDownButton (...)>
<Controls:DropDownButton.Resources>
<Style x:Key="{ComponentResourceKey ResourceId=MenuScrollViewer, TypeInTargetAssembly={x:Type FrameworkElement}}"
TargetType="{x:Type ScrollViewer}"
BasedOn="{StaticResource {x:Type ScrollViewer}}" />
</Controls.DropDownButton.Resources>
</Controls.DropDownButton>
This way the ScrollViewer within the drop-down will be styled with a default style shipped with MahApps.Metro.
To be certain that scrolling will behave as expected, you cannot rely on WPF to place a ScrollViewer where it should be.
As any content can be place on the dropdown, your best option is to drop a ScrollViewer straight onto the component.
This way, you can explicitly name it, and have access to its properties.
If you bind your list of countries to the lstContent box, you do away with all the messing.
<extToolkit:DropDownButton Content="Click Me" Margin="15" >
<extToolkit:DropDownButton.DropDownContent>
<ScrollViewer>
<ListBox Name="lstContent" ItemsSource="{Binding Countries}" ItemTemplate="{StaticResource CombinedTemplate}"/>
</ScrollViewer>
</extToolkit:DropDownButton.DropDownContent>
</extToolkit:DropDownButton>
Background:
I have a ListBox containing items defined by DataTemplates. Right now, if an object in the list has the property IsEditable set to true, the item's property information will be displayed inside of textboxes (via DataTemplate change), instead of textblocks (so the user can edit the content of that list item)
IsEditable is toggled on/off by a button inside of each list item. I have been told that we need to keep the state of all objects consistent, which means I can't just rebind the ItemsSource and lose everything.
Currently, I'm using this to re-render:
this.lbPoints.Dispatcher.Invoke(DispatcherPriority.Render, new Action(() => { }));
Question:
The aforementioned code snippet KIND OF does its job. By "kind of", I mean, it does eventually cause my data to become re-rendered, but only when I scroll to the bottom of the list and then scroll back up to the item i'm trying to re-render.
1) How can I re-render the data immediately without having to scroll around to get it to show up?
The guys commenting are right that you're going about this the wrong way... there is rarely a need to force a ListBox to re-render. You're probably causing yourself some additional grief trying to switch the DataTemplates (although it is possible). Instead of that, think about data binding the TextBox.IsReadOnly property to your IsEditable property:
<TextBox IsReadOnly="{Binding IsEditable}" Text="{Binding Text}" />
Another alternative is to use a BooleanToVisibilityConverter to show a different Grid in your DataTemplate when your IsEditable property is true. Unfortunately, that Converter doesn't have an inverse operation, so you could create an IsNotEditing property to bind to the Grid in the DataTemplate that is originally displayed. I'm not sure if that's clear... see this example:
<DataTemplate DataType="{x:Type YourPrefix:YourDataType}">
<Grid>
<Grid Visibility="{Binding IsNotEditing, Converter={StaticResource
BooleanToVisibilityConverter}}">
<!-- Define your uneditable UI here -->
</Grid>
<Grid Visibility="{Binding IsEditing, Converter={StaticResource
BooleanToVisibilityConverter}}">
<!-- Define your editable UI here -->
</Grid>
</Grid>
</DataTemplate>
You could also define your own BooleanToVisibilityConverter class that has an IsInverted property, so that you can just use the one IsEditing property. You'd need to declare two Converters still, like this:
<Converters:BoolToVisibilityConverter x:Key="BoolToVisibilityConverter" />
<Converters:BoolToVisibilityConverter x:Key="InvertedBoolToVisibilityConverter"
IsInverted="True" />
Then your XAML would be like this:
<Grid Visibility="{Binding IsEditing, Converter={StaticResource
InvertedBoolToVisibilityConverter}}">
<!-- Define your uneditable UI here -->
</Grid>
<Grid Visibility="{Binding IsEditing, Converter={StaticResource
BoolToVisibilityConverter}}">
<!-- Define your editable UI here -->
</Grid>
I have a stackpanel named "mystack" in my xaml file and I am adding buttons in it dynamically from the .cs file and want to remove the border of buttons in C# .cs file
what I really want is to populate this stackpanel with the buttons coming from a list of string
thanks in advance
xaml:
<Grid HorizontalAlignment="Left" Height="227" Margin="10,10,0,0" Grid.Row="2"
VerticalAlignment="Top" Width="530">
<ScrollViewer VerticalScrollBarVisibility="Auto">
<StackPanel Name="mystack" HorizontalAlignment="Left" Grid.Row="2"
VerticalAlignment="Top" Width="520"/>
</ScrollViewer>
</Grid>
.cs:
public List<String> Schools()
{
List<String> l = new List<string>();
l.Add("SST");
l.Add("SBE");
l.Add("SSH");
return l;
}
I agree with HighCore, you generally do not want to manipulate the UI elements in your code.
To remove the Border of the buttons you can set a Button's BorderThickness property to "0" in Xaml or to new Thickness(0) in the code-behind.
i.e.
myButton.BorderThickness = new Thickness(0);
EDIT:
Okay, I noticed your updated question. I would create a property that stores your list of schools and bind to it in a way similar to this:
public List<string> Schools
{
get { return _schools; }
set { _schools = value; }
}
Somewhere you need to set the DataContext of the control to your class containing the Schools property. If you are dynamically updating the list of Schools you'll need to implement INotifyPropertyChanged so the UI knows when to update. And then your Xaml would look something like this:
<ItemsControl ItemsSource="{Binding Schools}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Button Content="{Binding}" BorderThickness="0" />
</DataTemplate>
</ItemsControl.ItemTemplate>
<ItemsControl>
You can't remove button's border like: btn.BorderThicknes=new Thickness(0);
See this: Removing button's border
The fast Fix:
What I had to do to effectively hide the button border - and due to the button control template I believe which utilizes and changes Button border (i.e. even if you remove it it'd draw it on some trigger I believe)...
...was to set BorderBrush="Transparent" as well (I always do BorderThickness as well but I'm guessing it's not needed - only for visual/layout look'n'feel)
i.e. setting thickness alone is not enough.
I'm really not sure that's the bets way to do it, or actually I'm
quite sure there must be something smarter - but I always end up with
that.
The Right Way:
Proper way - and recommended - is to write your own Button template -
based on the Microsoft official one - or base it on it - and do what
you need w/o borders.
For the code behind/C#:
You really don't need that as per your changed question - do what others suggested already
the best way to do this is :
<Style TargetType="Button">
<Style.Resources>
<Style TargetType="{x:Type Border}">
<Setter Property="CornerRadius" Value="0"/>
</Style>
</Style.Resources>
</Style>
what I really want is to populate this stackpanel with the buttons
coming from a list of string
That's called a ListBox:
<ListBox ItemsSource="{Binding Items}">
<ListBox.ItemTemplate>
<DataTemplate>
<Button Content="{Binding}" BorderThickness="0"/>
<!-- Whatever other customizations to the button -->
</DataTemplate
</ListBox.ItemTemplate>
</ListBox>
ViewModel:
public class ViewModel
{
public ObservableCollection<string> Items {get;set;}
public ViewModel()
{
Items = new ObservablecCollection<string>();
Items.Add("String1");
Items.Add("String2");
Items.Add("String3");
}
}
You need to learn the MVVM pattern.
I'm starting a new project in WPF and am now looking into using Prism. For now I'm simply trying to set up the navigation of the application using Prism. Unfortunately, my lack of experience with the framework makes it a bit difficult to get started.
To be more precise about my first challenge I have an application with a "navigation/menu" region and a "main" region.
In "navigation/menu" region, I have several checkboxes, in this case we have four of them, which represents a sequential navigation. I.E. we've selected View 2 and View 4.
So, when the user click Start, in "main" region must appear each view selected in that order. Check the below image, View 2 is first. Then when the user press next, must show View 4.
I mean on a more structural level..
if I could only get through the first steps..
Prism support TabControl Region Adapter, navigation can be done using standard requestNavigation method.
You need add all your tab content using Region.Add method to the region in your module's init phase.
view:
<TabControl prism:RegionManger.RegionName="tabRegion" />
C# code:
IRegionManager manager;
manager.Regions["tabRegion"].Views.Add(Container.Resolve(typeof(YourViewType)));
In your viewModel, you should write you navigation command:
public void NextView() {
regionManager.RequestNavigation("tabRegion", new Uri("YourViewType", UriKind.Relative));
}
bind to your "next" button:
<Button Command="{Binding NextViewCommand}" />
If you want to control whether user can navigate to next page, you can implement INavigationAware interface.
If you don't want lost data between navigation, you can make your view model has ContainerMangedLifeCycle or implement IsNavigationTarget method to return true.
Sorry for untested code sample, but you should get the point.
Create a class named ViewVM with a property IsSelected. Must implement INotifyPropertyChanged.
Add an ObservableCollection<View> named Views to your datacontext. Populate it with new instances of ViewVM.
Put an ItemsControl in your Window, with ItemsSource set to Views. The DataTemplate for the ItemsControl items should contain a CheckBox (with IsChecked bound to IsSelected) and a Label.
Add a TabControl to your Window, with ItemSource set to Views. Add a Style for TabItem such that TabItems are only visible if IsSelected is true.
Following the above steps will give you a window containing a list of views with checkboxes, as you requested, and a TabControl displaying only the selected views. Below is the XAML (I have tested this):
<StackPanel>
<ItemsControl ItemsSource="{Binding Path=Views}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<CheckBox IsChecked="{Binding Path=IsSelected}"></CheckBox>
<TextBlock Text="{Binding Path=Title}"></TextBlock>
</StackPanel>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
<TabControl ItemsSource="{Binding Path=Views}">
<TabControl.ItemTemplate>
<DataTemplate>
<Grid>
<TextBlock Text="{Binding Path=Title}"></TextBlock>
</Grid>
</DataTemplate>
</TabControl.ItemTemplate>
<TabControl.Resources>
<Style TargetType="TabItem">
<Style.Triggers>
<DataTrigger Binding="{Binding Path=IsSelected}" Value="False">
<Setter Property="Visibility" Value="Collapsed"></Setter>
</DataTrigger>
</Style.Triggers>
</Style>
</TabControl.Resources>
</TabControl>
</StackPanel>
This addresses the structural/design aspect and should give you a good start to creating your solution - you'll also need to create a custom control to use instead of the TabControl. Instead of having tabs, your custom control should contain Next and Previous buttons to navigate between views.
I've got an ItemsControl with an ItemsSource of Hours.
I represent each item by a border (in the data template).
Now, each of those border has an hour data, and i want to retrieve that in code behind.
is it even possible?
my code example:
<ItemsControl x:Name="dayHours">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Border Name="dayHourBorder" Height="30" BorderBrush="#B0B6BE" Width="193" BorderThickness="1,0,1,1" Background="AliceBlue" Tag="{Binding Index}" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
And in the naive way, I would expect a code like:
(sender as Border).hourTime;
From your code, I am guessing that you are interested in finding the 'hourTime' in an event handler? When an ItemsControl creates an 'instance' of your DataTemplate for each item, it sets the DataContext of the template to the item itself. Therefore the following should work:
Border border = sender as Border;
MyItemType item = border.DataContext as MyItemType;
var hourTime = item.hourTime;