when entering the page with ListView for the first time, and adding items to the ListView, it works as expected, but when entering the page again, and press the add button, null reference exception is thrown.
TapGestureRecognizer not working correctly when tapping inside the DataGrid control on iOS and MacCatalyst platforms.
Workaround:
You could use CellTap or CellDoubleTap commands of the DataGrid control. Here are the links to our documentation articles: DataGrid Commands and DataGrid CellTap Command.
HI Team,
When using DynamicResource for any content inside the RadItemsControl, there are two problems:
- If I define them in ContentPage.Resources, the RadItemsControl it does not use it at all
- If I define them in App.Resources, the RadItemsControl will get the initial value, but not respond to any changes.
You can use the following code to verify, or use my attached demo
Resources (try them in both App.xaml and in ContentPage):
<Color x:Key="TitleTextColor">SlateBlue</Color>
DataTemplate
<DataTemplate x:Key="MonkeyItemTemplate">
<Grid Padding="10">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<Label Text="{Binding Name}"
FontAttributes="Bold"
TextColor="{DynamicResource TitleTextColor}"
Grid.Row="0" />
<Label Grid.Row="1"
Text="{Binding Location}"
FontAttributes="Italic"
VerticalOptions="End"
TextColor="{DynamicResource TitleTextColor}"/>
</Grid>
</DataTemplate>
View
<!-- Use CollectionView to see how it's supposed to operate -->
<CollectionView ItemsSource="{Binding Monkeys}"
ItemTemplate="{StaticResource MonkeyItemTemplate}"
SelectionMode="None"
Grid.Row="0"
Grid.Column="0"/>
<telerik:RadItemsControl ItemsSource="{Binding Monkeys}"
ItemTemplate="{StaticResource MonkeyItemTemplate}"
Grid.Row="0"
Grid.Column="1"
x:Name="ItemsControl1"/>
<Button Text="Change Colors"
Clicked="Button_OnClicked"
TextColor="{DynamicResource TitleTextColor}"
BackgroundColor="{DynamicResource SubtitleTextColor}"
Grid.Row="1"
Grid.ColumnSpan="2"/>
Code-behind
private bool isChanged;
private void Button_OnClicked(object sender, EventArgs e)
{
if (isChanged)
{
App.Current.Resources["TitleTextColor"] = Colors.SlateBlue;
}
else
{
App.Current.Resources["TitleTextColor"] = Colors.DarkRed;
}
isChanged = !isChanged;
}
<telerik:RadBusyIndicator x:Name="BusyTest"
IsBusy="{Binding IsBusy, Mode=TwoWay}"
AnimationContentColor="DodgerBlue"
AnimationContentHeightRequest="40"
AnimationContentWidthRequest="40"
VerticalOptions="Center"
HorizontalOptions="Center"
AnimationType="Animation6">
<telerik:RadBusyIndicator.Content>
<Label Text="{Binding LabelText, Mode=TwoWay}" TextColor="Blue" FontSize="16"/>
</telerik:RadBusyIndicator.Content>
<telerik:RadBusyIndicator.BusyContent>
<Label Text="{Binding LabelText, Mode=TwoWay}"
TextColor="Red" FontSize="20"/>
</telerik:RadBusyIndicator.BusyContent>
</telerik:RadBusyIndicator>Workaround:
set the text directly to the BusyContent:
<telerik:RadBusyIndicator x:Name="BusyTest"
IsBusy="{Binding IsBusy, Mode=TwoWay}"
AnimationContentColor="DodgerBlue"
AnimationContentHeightRequest="40"
AnimationContentWidthRequest="40"
VerticalOptions="Center"
HorizontalOptions="Center"
AnimationType="Animation6">
<telerik:RadBusyIndicator.Content>
<Label Text="{Binding LabelText, Mode=TwoWay}" TextColor="Blue" FontSize="16"/>
</telerik:RadBusyIndicator.Content>
<telerik:RadBusyIndicator.BusyContent>
<Label Text="Loading....."
TextColor="Red" FontSize="20"/>
</telerik:RadBusyIndicator.BusyContent>
</telerik:RadBusyIndicator>
Changing the ItemsSource property of the ListView causes it to recreate its cells. The problem is that the existing cells are never reclaimed by the garbage collector, so the memory usage grows constantly. Eventually, the application can run out of memory, if the ItemsSource is updated too many times.
Note: It is possible the memory leak is caused by the bindings holding objects longer than necessary. Similar memory leaks can be reproduced with the .NET MAUI CollectionView as well. Here are a few GitHub issues for the CollectionView that might be related:
- CollectionView leaks memory when ItemsSource has changed
- Massive memory leak in CollectionView while scrolling
- Memory leaks EVERYWHERE
When I register the pages and controls using AddTransient it works but when I use AddSingleton it doesn't.
System.InvalidOperationException: PlatformView cannot be null here [mono-rt] at Microsoft.Maui.Handlers.ViewHandler`2[[Microsoft.Maui.ILayout, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[Microsoft.Maui.Platform.LayoutViewGroup, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].get_PlatformView() in ViewHandlerOfT.cs:line 36 [mono-rt] at Telerik.Maui.Handlers.RadMaskedEntryHandler.GetTextInputFromNativeVisualTree() [mono-rt] at Telerik.Maui.Handlers.RadMaskedEntryHandler.UpdateNativeTextInput() [mono-rt] at Telerik.Maui.Handlers.RadMaskedEntryHandler.NativeView_ChildViewRemoved(Object sender, ChildViewRemovedEventArgs args)
Header Text, group header text, do not display some languages characters like Chinese, Thai, etc.
The root reason for this is the fact that the Skia APIs used to draw the text does not support automatic character fallback.
Workaround:
for header text:
<telerik:DataGridTextColumn.HeaderContentTemplate>
<DataTemplate>
<Label Text="your text"></Label>
</DataTemplate>
</telerik:DataGridTextColumn.HeaderContentTemplate>group header text
<telerik:RadDataGrid.GroupHeaderTemplate>
<DataTemplate>
<Label Text="{Binding Group.Key}"/>
</DataTemplate>
</telerik:RadDataGrid.GroupHeaderTemplate>column:
<telerik:DataGridTextColumn HeaderText="Name" >
<telerik:DataGridTextColumn.CellContentTemplate>
<DataTemplate>
<Label Text="{Binding Name}"/>
</DataTemplate>
</telerik:DataGridTextColumn.CellContentTemplate>
</telerik:DataGridTextColumn>
Hi,
I'am testing Telerik .NET MAUI controls for windows and android. FontFamily property of columns (both for xaml and app.xaml) not working. If an embedded font is choosen for whole application, DataGrids look different from other parts of the application
here is my xaml, "fnt_bold" is a MauiFont in resources. All other ui components are shown in my font
<telerik:RadDataGrid x:Name="dataGrid" AutoGenerateColumns="False" UserEditMode="None" UserGroupMode="Disabled" SelectionMode="Single" SelectionUnit="Row" >
<telerik:RadDataGrid.Columns>
<telerik:DataGridTextColumn PropertyName="ID" HeaderText="RefID" Width="60" SizeMode="Fixed">
<telerik:DataGridTextColumn.CellContentStyle>
<telerik:DataGridTextCellStyle FontFamily="fnt_bold" FontSize="12.25"/>
</telerik:DataGridTextColumn.CellContentStyle>
</telerik:DataGridTextColumn>
<telerik:DataGridTextColumn PropertyName="CODE" HeaderText="Code" Width="80" SizeMode="Fixed">
<telerik:DataGridTextColumn.CellContentStyle>
<telerik:DataGridTextCellStyle FontFamily="fnt_bold" FontSize="12.25"/>
</telerik:DataGridTextColumn.CellContentStyle>
</telerik:DataGridTextColumn>
<telerik:DataGridTextColumn PropertyName="NAME" HeaderText="Name" Width="250" SizeMode="Fixed">
<telerik:DataGridTextColumn.CellContentStyle>
<telerik:DataGridTextCellStyle FontFamily="fnt_regular" FontSize="12.25"/>
</telerik:DataGridTextColumn.CellContentStyle>
</telerik:DataGridTextColumn>
</telerik:RadDataGrid.Columns>
</telerik:RadDataGrid>I have attached a screenshot from my test app.
I also checked the sample telerik android app (Telerik UI for .NET MAUI Controls). DataGrid components in Telerik Sample app also dont use the expected font unlike all other ui components.
Just one of the DataGrid samples of one column in the sample app has the correct fontfamily property. I have attached that screenshot also. I couldn't figure out how to implement it.
Am i missing something?
Thanks in advance.
Ender
Having this setup:
<telerikDataGrid:DataGridTemplateColumn HeaderText="Age"
CanUserSort="True">
<telerikDataGrid:DataGridTemplateColumn.CellContentTemplate>
<DataTemplate>
<Label Text="{Binding Age}" />
</DataTemplate>
</telerikDataGrid:DataGridTemplateColumn.CellContentTemplate>
<telerikDataGrid:DataGridTemplateColumn.SortDescriptor>
<telerikCommon:PropertySortDescriptor PropertyName="Age" SortOrder="Descending" />
</telerikDataGrid:DataGridTemplateColumn.SortDescriptor>
</telerikDataGrid:DataGridTemplateColumn>
When applying SortDescriptor to the Template column, the column is not initially sorted.
A line going through the clear button of the RadEntry control. The behavior is reproduced on Android 9.0
Error: BindingExpression path error: 'HandleIconPath' property not found on 'Telerik.Maui.Controls.Compatibility.DataControlsRenderer.UWP.ExtendedListViewItem'. BindingExpression: Path='HandleIconPath' DataItem='Telerik.Maui.Controls.Compatibility.DataControlsRenderer.UWP.ExtendedListViewItem'; target element is 'Microsoft.UI.Xaml.Controls.BitmapIcon' (Name='PART_ReorderHandle'); target property is 'UriSource' (type 'Uri')
windows device with touch capabilities/monitor with touch -> the listview swipes and shows the swipe template, however pressing the button in the swipe or attempting to close the swipe makes the swipe content disappear and the entry to remain in the swiped position.Also multiple swipes are allowed. The swipe cannot be ended, etc.
Using the mouse - > swiping works as expected.
The bug can be reproduced quite easily with the SDK examples. Choose any ListView example from the LoadOnDemand category that uses LoadOnDemandMode set to Automatic, e.g. ListView/LoadOnDemand/LoadOnDemandEvent. Remove the initial items from the ItemsSource:
public ViewModel()
{
this.Source = new ObservableCollection<string>();
//for (int i = 0; i < 14; i++)
//{
// this.Source.Add(string.Format("Item {0}", i));
//}
this.LoadItemsCommand = new Command(this.LoadItemsCommandExecute);
}Run the example to observe the exception almost immediately.
DataGrid is added inside pages that can be accessed through shell flyout menu.
And the exact steps to reproduce the issue:
Go to page GridOne page in flyout menu.Enter any element by double tap. this navigates to another page - SubGridPage
On SubGridPage again double tap any element. this navigates to another page - InnerModel
When you are in InnerModel page select from flyout menu GridTwo page
On GridTwoPage double tap any element, this navigates to another page - SubGridPage
On SubGridPage double tap any element. this navigates to another page - InnerModel
When you land on InnerModel page go back to Grid One on flyout menu.
When you are in the GridOne InnerModel, press the back arrow.
It navigates to the SubGridPage. but the DataGrid is not visualized.
I don't have definitive proof on when it started but I did update my Telerik.UI.for.Maui NuGet package from Trial to an official licensed version and that is when I started to see bizarre behavior for the ButtonToolbarItem control. Suddenly, NO FONT ICONS show! Also, in my log file, I see this:
Unable to load font 'TelerikFont'.
I don't have this font installed in my Maui Resources\Fonts folder nor do I load it in my MauiProgram ConfigureFonts extension method for the MauiApp builder. It was working until two days ago.
I turned on BLAST mode in my debugger where I was seeing exceptions being thrown all over the place with regard to loading fonts. I am up against a crucial investor funding demo so I do not have the time to dig down to the core of this issue at the moment. This issue I am logging is there for you to ask me questions on things I can verify so we can work on this together.
What are some of the things you need me to do or look at to report back... The fact that NONE of my FontImageSource icons are being displayed in my RadToolBar ButtonToolbarItems is suspect. The reporting of the TelerikFont is even more suspect. I wasted a TON of valuable time today trying to find a workaround, but none could be found. GitHub Copilot and ChatGPT kept giving me bogus answers for properties on your controls that don't exist which only exacerbated my frustration. I tried to use PNG files as the icon, but your ButtonToolbarItem image source only allows font image sources which I think is a very bad design decision on your behalf. What if a font does not provide the correct image I wish to display? You really should allow png images to be used on these buttons!!!
Like I said, it was working up until several days ago...
Thanks, Steve