I have a ListView with the default SeparatorVisibility. My Android project shows the Separator if there are elements in the ItemsSource and stops showing it below the last element. It's the result I want for my iOS project.
However, in my iOS project the screen is full of Separators no matter how many elements I have, even if I have no elements or only one, the Separators still being there.
Could someone give me a reason and how to fix it please? Thanks.
I think you can take a look to this post
these are some tips
First disable the default separator, this is done by adding following property to the ListView XAML
SeparatorColor="Transparent"
After this, wrap the complete ViewCell content inside a double StackLayout! I know this sounds like overkill but this way you’ll not run into any BoxView issues regarding margins inside the ViewCell… or other stuff.
The first StackLayout should have a BackgroundColor set to the colour you want your separator to be, the second StackLayout should have the same BackgroundColor as the rest of the container it is in… in our example the page and that is set to white. Be sure to also add a Margin to the bottom of this second StackLayout because that will represent the thickness of our separator!
I think you can play with this "Margin"... when your data is empty, remove the margin so you should not have the separator
<ListView x:Name="SeparatorListView"
SeparatorColor="Transparent"
ItemsSource="{Binding Persons}"
Margin="0,20,0,0"
RowHeight="60"
HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand"
BackgroundColor="White"
Grid.Row="1">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell IsEnabled="false">
<StackLayout VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand"
BackgroundColor="Black">
<StackLayout VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand"
BackgroundColor="White"
Margin="0,0,0,0.4">
<StackLayout VerticalOptions="CenterAndExpand" HorizontalOptions="FillAndExpand" Spacing="0">
<Label Text="{Binding FullName}" TextColor="Maroon" VerticalOptions="CenterAndExpand" Margin="20,0,20,0" />
<Label Text="{Binding Profession}" TextColor="Maroon" VerticalOptions="CenterAndExpand" Margin="20,0,20,0" />
</StackLayout>
</StackLayout>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
With that in place, you’ll get the same visual result as the preview image at the top right of this blog post.
As a bonus, you could omit one of the StackLayouts IF your page has a background color other than white. Because if this is the case, you can use that color as the separator color by playing with transparency inside the ListView.
Example of this, note will only work if the page itself also has a BackgroundColor set to Olive!
<ListView x:Name="SeparatorListView"
SeparatorColor="Transparent"
ItemsSource="{Binding Persons}"
Margin="0,20,0,0"
RowHeight="60"
HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand"
BackgroundColor="Olive"
Grid.Row="1">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell IsEnabled="false">
<StackLayout BackgroundColor="#f4eac3"
Padding="0,5,0,5"
HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand">
<StackLayout BackgroundColor="Transparent"
HorizontalOptions="FillAndExpand" VerticalOptions="CenterAndExpand"
Spacing="0"
Margin="20,0,20,0">
<Label Text="{Binding FullName}" TextColor="Maroon" VerticalOptions="CenterAndExpand" />
<Label Text="{Binding Profession}" TextColor="Maroon" VerticalOptions="CenterAndExpand" />
</StackLayout>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
using UIKit;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;
[assembly: ExportRenderer (typeof(ListView), typeof(CustomListViewRenderer))]
namespace yourNamespace
{
public class CustomListViewRenderer : ListViewRenderer
{
protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.ListView> e)
{
base.OnElementChanged(e);
if (e.NewElement != null)
{
var listView = Control as UITableView;
listView.SeparatorInset = UIEdgeInsets.Zero;
}
}
}
}
That is due to the implementation of the ListView on the iOS side. It renders as a UITableView which (in the case of the ListView) always takes the entire height and shows empty items. To change this type of behavior you could set the ListView height dynamically in the code-behind for your page. Another option is taking a look at Xamarin's Evolve sample app which has a few pages where it uses a CardView combined with a ListView to make it appear as it does on Android.
<Image
x:Name="btnThickness"
BackgroundColor="Transparent"
Source="width"
HorizontalOptions="CenterAndExpand"
VerticalOptions="CenterAndExpand"
WidthRequest="40"
HeightRequest="40">
<Image.GestureRecognizers>
<TapGestureRecognizer Tapped="TappedBehaviourEvent"></TapGestureRecognizer>
<TapGestureRecognizer BindingContext="{x:Reference widthPicker}" Command="{Binding OpenCommand}"></TapGestureRecognizer>
</Image.GestureRecognizers>
</Image>
I have written an xaml file which have an image with two tap gesture recogniser: First TapGesture is to set the other view's visible to false and the second tap gesture is to show a selected view. On Android, it works fine and able to call the TappedBehaviourEvent and the second command whereas on IOS it only call the second line of the TapGesture not the first one.
Is there something need to be added to have it work...
Is there a possibility to use the Surface-keyboard to alter text in a normal textbox?
I'm creating a textbox and add the text in code behind. And now I want that the user can change the text if he touches the text.
<Grid x:Name="TextContainer" Margin="0,0,0,0" Background="Transparent" Height="66" Width="66">
<TextBlock x:Name="contentTextBlock" Margin="0" Text="NodeDesign_X" VerticalAlignment="Center" d:LayoutOverrides="Width" HorizontalAlignment="Center" Foreground="White" TextTrimming="CharacterEllipsis" TextWrapping="WrapWithOverflow" />
</Grid>
I didn't find possibilities to alter the SurfaceTextBox in the way my TextBlock locks now.
Thanks in advance!
Use a TextBox instead of TextBlock then the user can change the text. If you are in Surface Mode the Keyboard will be automatic popup if the TextBox gets the focus.
I have a listbox bound to a view model property called Choices. Each choice has a label and an index. I need to bind the buttons in the list to a command on the same view model. So far Ive figured out this much:
<ListBox Grid.Row="1" ItemsSource="{Binding Choices}" SelectedIndex="{Binding SelectedChoice, Mode=TwoWay}" >
<ListBox.ItemTemplate>
<DataTemplate>
<Grid HorizontalAlignment="Stretch" Margin="1">
<Button Content="{Binding Caption}" Height="24" HorizontalAlignment="Stretch"
Command="{Binding RelativeSource={RelativeSource ???},
Path=SelectChoice}" CommandParameter="{Binding}"/>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
I cant figure out what RelativeSource to use for the command and I'm not sure the CommandParameter is correct.
This seems a really simple thing to do but it's obviously too simple for my poor old brain. Can anyone help please?
Thanks
Sorted:
<ItemsControl Grid.Row="1" ItemsSource="{Binding Choices}" >
<ItemsControl.ItemsPanel >
<ItemsPanelTemplate >
<StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
</StackPanel>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<Button Content="{Binding Caption}" Height="24" HorizontalAlignment="Stretch" Margin="0,0,4,0"
Command="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type ItemsControl}}, Path=DataContext.SelectChoice}"
CommandParameter="{Binding}"/>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
I have a popup within a user control. The popup uses a TextBox to show a textual preview of data produced by the control.
How do I make the popup size itself to the user control it's inside of? With code as shown below, I find that the text box is sized according to its content, and the popup is sized according to the textbox.
It works fine if I use fixed sizes in my row and column definitions, but I would like to popup to resize itself to match the user control (which in turn matches the browser).
<UserControl
<!-- usual stuff here -->
>
<Grid>
<!-- layout for the user control here -->
<!-- and after that my popup: -->
<Popup Name="MyPopup">
<Border BorderBrush="Black" BorderThickness="2" >
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="22"></RowDefinition>
<RowDefinition Height="*"></RowDefinition>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"></ColumnDefinition>
</Grid.ColumnDefinitions>
<TextBlock Grid.Row="0" Text="Preview:" Margin="5" ></TextBlock>
<TextBox
Grid.Row="1"
Name="MyTextBox"
IsReadOnly="True"
HorizontalScrollBarVisibility="Visible"
VerticalScrollBarVisibility="Visible"
TextWrapping="Wrap"
Margin="5"
>
</TextBox>
</Grid>
</Border>
</Popup>
</Grid></UserControl>
The C# code to do this would be something like:
textBox1.Width = UserControl.Width;
textBox1.Height = UserControl.Height;
textBox1.Margin = UserControl.Margin;
The key here is resetting the margin. I know this works in WPF to, say, fill a Window with a TextBox. Give it a try, see if it works.