I'm defining a list view as follows:
<ListView Grid.Row="0" Grid.Column="1" ItemsSource="{Binding MenuList}"
SelectedItem="{Binding SelectedEngine, Mode=TwoWay}" SeparatorVisibility="None">
<ListView.RowHeight>
<OnPlatform x:TypeArguments="x:Int32">
<On Platform="Android">52</On>
<On Platform="UWP">154</On>
</OnPlatform>
</ListView.RowHeight>
</ListView>
But I get an error message saying:
No property, bindable property, or event found for 'RowHeight', or mismatching type between value and property.
And if I drop the out it compiles. Does anyone know how I can fix the issue?
I am on VS for Mac v7.4.1 and XF v2.5.0.121934 your code is compiling with enabled XAMLC and working as expected. What is your setup?
Try to update to latest and greatest version of Xamarin.Forms.
Related
I am currently working on a UI for an application and I want to align the following label Text automatically horizontally, so I wanted to test, how I can align text normally.
The Label Documentation of Maui state, that I have to do it with the HorizontalTextAlignment Element. I tried it several times and it worked, but here it won't:
<CollectionView Grid.Row="1" BackgroundColor="Black">
<CollectionView.ItemsSource>
<x:Array Type="{x:Type models:MessageModel}">
<models:MessageModel Message="Hallo" Created="01.01.2001 00:00:00"/>
<models:MessageModel Message="Hey na!" Created="01.01.2001 00:00:00"/>
</x:Array>
</CollectionView.ItemsSource>
<CollectionView.ItemTemplate>
<DataTemplate x:DataType="models:MessageModel">
<Label HorizontalTextAlignment="End" TextColor="White" Text="{Binding Created}"/>
</DataTemplate>
</CollectionView.ItemTemplate>
</CollectionView>
The Output is the following (And yeah I could use one Label, but I wanted to try both ways):
Edit: adding the following Element HorizontalOptions="FillAndExpand" at the label + a Background Color:
Edit2:
I feel like I'm missing something obvious because this is so simple. Thanks in advance for the help. I'm struggling with binding the SelectedItem of a simple ListView in a Xamarin application. I'm testing on UWP and am using Prism's MVVM BindableBase base class. Here's what I'm experiencing:
The page loads and nothing in the list is selected.
I select an item in the list.
The setter of SelectedGrade is called with a value of null.
After that, selecting items does not cause the SelectedGrade setter to be called.
Here's the relevant XAML:
<ListView BackgroundColor="#7F7F7F"
CachingStrategy="RecycleElement"
IsPullToRefreshEnabled="True"
IsRefreshing="{Binding IsBusy, Mode=OneWay}"
ItemsSource="{Binding Grades, Mode=OneWay}"
SelectedItem="{Binding SelectedGrade, Mode=TwoWay}"
RefreshCommand="{Binding RefreshCommand}"
RowHeight="50">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout HorizontalOptions="FillAndExpand"
VerticalOptions="CenterAndExpand"
Orientation="Horizontal"
Padding="10">
<Label HorizontalOptions="FillAndExpand"
Text="{Binding Title}"
TextColor="#272832"/>
<Label HorizontalOptions="FillAndExpand"
Text="{Binding Score}"
TextColor="Aquamarine" />
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
Here's the ViewModel:
Grade _selectedGrade;
public Grade SelectedGrade
{
get { return _selectedGrade; }
set { SetProperty(ref _selectedGrade, value); } // this gets set to NULL the first time i select an item then never gets set again
}
Edit: I've also added an ItemSelected event listener in the code-behind and it is not being fired after the initial item is selected. The one time it is fired, the SelectedItemChangedEventArgs reveal that the ListView's SelectedItem is null. I can also see at this time that the ListView's ItemsSource has a collection of three items in it, as I would expect. I'm quite confused as to why the ListView thinks the SelectedItem is null and why it is not broadcasting when the selected item changes.
It looks like this was a bug in Xamarin. I upgraded from Xamarin.Forms 3.0.0.550146 to 3.1.0.637273 and now it works.
I have faced with the similar issue when List does not bind to view model with SelectedItem and Xamarin forms 5.0.0.2244.
It was resolved with setting default value of List property to new List() object instead null value in the view model before setting binding context . After that binding has became working.
I am trying to create a listview where users can select the list item to view the store and also be able to click on the image to take them to the product detail.
How can I add a command in the ViewCell?
<ListView ItemsSource="{Binding myData}" x:Name="myListView" SelectedItem="{Binding SelectedStore}" >
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<Grid>
<Label Text="{Binding Title}" />
<Image Source="product.png" >
<Image.GestureRecognizers>
<TapGestureRecognizer Command="{Binding ItemTapCommand}" CommandParameter="Id" />
</Image.GestureRecognizers>
</Image>
</Grid>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
public ICommand ItemTapCommand => new Command(ShowSelectedProductAsync());
private async Task ShowSelectedProductAsync()
{
//take them to view the item detail
}
The problem is that you are attempting to bind to a command that is not located on the individual item within the ListView; the BindingContext on your Image is the individual items inside your myData collection.
With other frameworks, for example, Wpf, you would simply use the RelativeSource part of binding to tell the control to look for your command on the BindingContext of another control, however this isn't possible in Xamarin Forms (RelativeSource is not supported).
What you can do is the following, but it requires your UserControl to have an x:Name:
<TapGestureRecognizer Command="{Bindind Path=BindingContext.ItemTapCommand,
Source={x:Reference MyUserControl}}"
CommandParameter="{Binding Id}" />
What this says is to use the UserControl as the source for the binding, and the property is a nested property on that UserControl composed of BindingContext.ItemTapCommand.
As a bonus, I updated the code because I felt that you probably meant to bind the value of the Id property of each record as the command parameter, and not merely to send the string "Id" as the command parameter.
I am new to Silverlight. I am trying to provide a zoom in functionality along with inkpresenter. I am using Silverlight 4, c#, asp.net. I can bind the slider to canvas and it does zoom in but i am facing problem with the scrollviewer layout which is not updating. there are allot of post that mentioned that i need to used layout transform. Can any one please let me know what i am doing wrong or any other suggestion.
<Slider x:Name="slider" Maximum="2" Minimum="0" Value="1" Width="100"/>
</StackPanel>
<ScrollViewer x:Name="scrollBar" VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto" Grid.Column="1" Margin="6,1,1,1" Grid.Row="1">
<ScrollViewer.Content>
<toolkit:LayoutTransformer Name="TheTransformer" Background="{x:Null}">
<toolkit:LayoutTransformer.LayoutTransform>
<ScaleTransform x:Name="contentScale" ScaleX="{Binding ElementName=slider,Path=Value}" ScaleY="{Binding ElementName=slider,Path=Value}" />
</toolkit:LayoutTransformer.LayoutTransform>
<toolkit:LayoutTransformer.Content>
<Canvas x:Name="cnsImageEditable" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" OpacityMask="#FFE89E9E">
<!--The following commented bit does work i can zoomin and out but scroller not updating -->
<!--<Canvas.RenderTransform>
<ScaleTransform x:Name="scale" ScaleX="{Binding ElementName=slider,Path=Value}" ScaleY="{Binding ElementName=slider,Path=Value}"/>
</Canvas.RenderTransform>-->
<InkPresenter x:Name="inkCanvas" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
<Image x:Name="imgEditableImage" HorizontalAlignment="Stretch" VerticalAlignment="Stretch"></Image>
</InkPresenter>
</Canvas>
</toolkit:LayoutTransformer.Content>
</toolkit:LayoutTransformer>
</ScrollViewer.Content>
</ScrollViewer>
any help is much appretiated thanks
Check out https://stackoverflow.com/questions/9899729/layouttransformer-in-silverlight-not-working , worked for me. Specifically:
I found that Transforms in silverlight happens after Layout, so I changed the CanvasWidth property only once till the scrollbars show, and then zooming would work perfectly,
I have a window with a TabControl that i've bind to a list of objec, I'll called MyItem :
<TabControl Name="MyTabPNL" Background="Gainsboro"
ItemsSource="{Binding MyItemList, ElementName=WatcherWindow}"
ContentTemplate="{StaticResource tabItemTemplate}">
</TabControl>
This MyItem class has an ObservableCollection, that I want to bind to a Listview, I'm doing this with a DataTemplate.
GOAL: I'd like to sort automatically this ObservableCollection in XAML. Usually i would use a CollectionViewSource, but i can't find a way to this... I've tried stuff like that:
<DataTemplate x:Key="tabItemTemplate">
<DataTemplate.Resources>
<CollectionViewSource x:Key='dayList' Source="{Binding MyDayList}">
<CollectionViewSource.SortDescriptions>
<scm:SortDescription PropertyName="MyDate" Direction="Descending" />
</CollectionViewSource.SortDescriptions>
</CollectionViewSource>
</DataTemplate.Resources>
<Grid >
<ListView ItemsSource="{Binding Source={StaticResource dayList}}" >
<ListView.View>
<GridView x:Name="gridvwDay" >
<GridViewColumn Header="MyDate"
CellTemplate="{StaticResource myCellTemplatePNLDate}"
HeaderContainerStyle="{StaticResource CustomHeaderStyleNeutral}"
Width="70" />
</GridView>
</ListView.View>
</ListView>
</Grid>
But everytime i've got the same error:
System.Windows.Data Error: 2 : Cannot
find governing FrameworkElement or
FrameworkContentElement for target
element.
BindingExpression:Path=MyDayList;
DataItem=null; target element is
'CollectionViewSource'
(HashCode=58368655); target property
is 'Source' (type 'Object')
I can't find a way to make a link between the dayList in the ListView ItemsSource, and the dayList in the CollectionRessource.
Do you guys have an idea?
FYI: pre sorting the ObservableCollection is not doable, because of the nature of the Class i'm using.
Have you tried simply,
<ListView ItemsSource="{StaticResource dayList}">
As per the doc: http://msdn.microsoft.com/en-us/library/ms750950.aspx
You don't need to bind when its just static on the page :)