I have a CollectionView where the ItemsSource is bound with a List. The contents of this list should be displayed in the Text of the Button. To do this I use Text={Binding .}.
When the page loads, I get empty buttons with no text. If I then remove the . and retype it in the {Binding .}, the text will appear in my buttons.
Can someone explain this to me or explain what I'm doing wrong?
.xaml
<StackLayout>
<CollectionView x:Name="ItemsListView" ItemsSource="{Binding CurrentQuizItem.Answers}" SelectionMode="None">
<CollectionView.ItemTemplate>
<DataTemplate>
<StackLayout >
<Button Text="{Binding .}" Command="{Binding Source={RelativeSource AncestorType={x:Type viewmodel:TakeQuizPageViewModel}}, Path=AnswerClickedCommand}" Style="{StaticResource AnswerButton}"/>
</StackLayout>
</DataTemplate>
</CollectionView.ItemTemplate>
</CollectionView>
</StackLayout>
Related
How do I set static text as Carousal view items instead of doing data binding? Here in the below code I am trying to have Page 2 appear when the user swipes to the left. This code says The property ItemTemplate is set more than once
<StackLayout Margin="10">
<CarouselView>
<CarouselView.ItemTemplate>
<DataTemplate>
<Grid>
<Label Text="Page 1"/>
</Grid>
</DataTemplate>
</CarouselView.ItemTemplate>
<CarouselView.ItemTemplate>
<DataTemplate>
<Grid>
<Label Text="Page 2"/>
</Grid>
</DataTemplate>
</CarouselView.ItemTemplate>
</CarouselView>
</StackLayout>
If you want to set the items statically in xaml itself without data binding you can use Array markup extension of type string:
<StackLayout Margin="10">
<CarouselView>
<CarouselView.ItemsSource>
<x:Array Type="{x:Type sys:String}">
<sys:String>Page 1</sys:String>
<sys:String>Page 2</sys:String>
</x:Array>
</CarouselView.ItemsSource>
<CarouselView.ItemTemplate>
<DataTemplate>
<Grid>
<Label Text="{Binding .}" />
</Grid>
</DataTemplate>
</CarouselView.ItemTemplate>
</CarouselView>
</StackLayout>
PS: Don't forget to add the required xaml namespace:
xmlns:sys="clr-namespace:System;assembly=mscorlib"
In my XAML File after changing some code inside it and then debug on my phone, the changes I made do not reflect on my phone. It keep showing my old code.
Old code :
<ListView
ItemsSource="{Binding Allgroups}"
RowHeight="75"
IsGroupingEnabled="true">
<ListView.ItemTemplate>
<DataTemplate>
<Label Text="{Binding NameNative}"></Label>
</DataTemplate>
</ListView.ItemTemplate>
<ListView.GroupHeaderTemplate>
<DataTemplate>
<ViewCell>
<Label Text="{Binding TitleWithItemCount}" />
</ViewCell>
</DataTemplate>
</ListView.GroupHeaderTemplate>
</ListView>
new code :
<Label Text="HELOO WORLD "></Label>
I Noticed every time i run the code , it keep showing the list.I have to click the save button then the list disappear and hello world appear .
I reset VS settings and relaunched it .
worked for me
<CollectionView ItemsSource="{Binding Categoriesxx}" IsGrouped="True">
<CollectionView.ItemsLayout>
<GridItemsLayout Orientation="Vertical" Span="1" VerticalItemSpacing="5" HorizontalItemSpacing="5"></GridItemsLayout>
</CollectionView.ItemsLayout>
<CollectionView.ItemTemplate>
<DataTemplate>
<StackLayout >
<Label Text="{Binding NameNative}"></Label>
</StackLayout>
</DataTemplate>
</CollectionView.ItemTemplate>
<CollectionView.GroupHeaderTemplate>
<DataTemplate>
<StackLayout BackgroundColor="AliceBlue">
<Label Text="{Binding Name}" FontSize="Title"></Label>
<Button Image="{Binding StateIcon}"
BackgroundColor="Transparent"
BorderColor="Transparent"
BorderWidth="0"
Command="{Binding BindingContext.ExpandCommand ,Source={x:Reference ServiceListPage}}"/>
</StackLayout>
</DataTemplate>
</CollectionView.GroupHeaderTemplate>
</CollectionView>
Why can I not use a TextCell like this in a ListView item template? When I use it the rows render but they are empty.
<ListView ItemsSource="{Binding Courses}">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Vertical">
<TextCell Text="{Binding Title}" Detail="{Binding SubTitle}"></TextCell>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
When using a Label I can see the text contents in each row:
<ListView ItemsSource="{Binding Courses}">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Vertical">
<Label Text="{Binding Title}"></Label>
<Label Text="{Binding SubTitle}"></Label>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
Is there anyway I can use the TextCell inside the list item template? I am trying to build a more complext layout inside the StackLayout and it would be greatly simplified if I could re-use the Title/Detail structure of the TextCell.
According to the Xamarin.Forms Cell Reference, cells are only designed to be added to ListViews or TableViews. In particular, it says:
However Cell is not a visual element, it just describes a template for
creating a visual element.
So it cannot be added directly to the children of a StackLayout. You will have to create a ViewCell with a custom template for that.. You can probably look at the source code on Github to find out the proper spacing that a TextCell uses between it's Text and TextDetail labels, to keep it consistent.
You Can Use Stack Layout in a text cell!
Here is the way for using it.
<TextCell>
<TextCell.BindingContext>
<StackLayout Orientation="Horizontal" >
<Label Text="{Binding Name}"
HorizontalOptions="CenterAndExpand" TextColor="Black"/>
<Label Text="{Binding Description}"
HorizontalOptions="CenterAndExpand" TextColor="Black"/>
<Label Text="{Binding Price}"
HorizontalOptions="CenterAndExpand" TextColor="Black"/>
</StackLayout>
</TextCell.BindingContext>
</TextCell>
I want to have some space around the Image cell items of a ListView:
<StackLayout>
<ListView ItemsSource="{Binding Items}" HasUnevenRows="True">
<ListView.ItemTemplate>
<DataTemplate>
<ImageCell Text="{Binding Title}" ImageSource="{Binding Image}" TextColor="Black" DetailColor="Gray"/>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
but there's no Margin property available for the ImageCell?
EDIT
I did what cvanbeek suggested before posting the question:
<DataTemplate>
<StackLayout Padding="5">
<ImageCell Text="{Binding Title}" ImageSource="{Binding Image}" TextColor="Black" DetailColor="Gray"/>
</StackLayout>
</DataTemplate>
but I got this exception:
Unhandled Exception:
System.InvalidCastException: Specified cast is not valid.
in the OnCreate method in MainActivity.cs
DataTemplate definition
Only View can be put inside DataTemplate, however StackLayout is Layout.
Use a ViewCell instead , it is more flexible and controllable.
<ListView >
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Padding="20" Orientation="Horizontal" >
<Label Margin="20" Text="123"/>
<Image Source="Assets/StoreLogo.png"/>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
<ListView
ItemsSource="{Binding Messages}"
Grid.ColumnSpan="2"
HeightRequest="100">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<ViewCell.View>
<StackLayout>
<Label
Text="{Binding When}"
XAlign="Center"/>
<StackLayout
BackgroundColor="Gray"
Orientation="Vertical"
VerticalOptions="Center">
<Label
Text="{Binding Message}"
XAlign="Start"/>
<Label
Text="{Binding Sender}"
XAlign="Start"
TextColor="Red"/>
</StackLayout>
</StackLayout>
</ViewCell.View>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
I am rendering a custom ListView in Xamarin.Forms application. The StackLayout which contains two Labels (to which "Message" and "Sender" has been bound), currently displays only one child. With the code above, it displays only "Message". If I change code to be
<StackLayout
BackgroundColor="Gray"
Orientation="Vertical"
VerticalOptions="Center">
<Label
Text="{Binding Sender}"
XAlign="Start"
TextColor="Red"/>
<Label
Text="{Binding Message}"
XAlign="Start"/>
</StackLayout>
it displays only sender. In short it is displaying only first child. What have I done wrong here ?
Issue was similar to what #Grisha had pointed out. RowHeight was proving to be lesser, and the second StackLayout was getting clipped.
The solution was to set HasUnevenRows property of the ListView to be TRUE. Thus, RowHeight was calculated automatically.