Hello, I made an App for Xamarin.Android using RadRadialGauge. I have a Thread that updates the indicator every 500ms based on a received value. The problem is that the longer the App runs the slower it becomes. I checked the RAM usage and it increases really fast, it reaches 200MB in a matter of a few minutes and as result the App becomes very laggy and it doesn't show a good performance. When I try to comment the indicator it works fine. I would like to ask if there is a way to reduce the RAM usage. Here is my Code: 

MainPage.xaml

<telerikGauges:RadRadialGauge StartAngle="180" SweepAngle="360">
                <telerikGauges:RadRadialGauge.Axis>
                    <telerikGauges:GaugeLinearAxis Maximum="100"
                                                       Minimum="0"
                                                       ShowLabels="False"
                                                       StrokeThickness="0" />
                </telerikGauges:RadRadialGauge.Axis>
                <telerikGauges:RadRadialGauge.Ranges>
                    <telerikGauges:GaugeRangesDefinition Offset="0">
                        <telerikGauges:GaugeRange Color="#DDDDDD"
                                                      From="0"
                                                      To="100" />
                    </telerikGauges:GaugeRangesDefinition>
                </telerikGauges:RadRadialGauge.Ranges>
                <telerikGauges:RadRadialGauge.Indicators>
                    <telerikGauges:GaugeBarIndicator x:Name="Needle1" EndCap="Oval"
                                        Fill="#a13127"
                                        StartCap="Oval"
                                        Offset="0"
                                        Value="0.45" />
                </telerikGauges:RadRadialGauge.Indicators>
            </telerikGauges:RadRadialGauge>
            <Label x:Name="GaugeLabel" FontSize="44"
                           HorizontalTextAlignment="Center"
                           Text="120"
                           TextColor="#a13127"
                           VerticalTextAlignment="Center" />

MainPage.xaml.cs

Thread t = new Thread(new ThreadStart(() =>
                {
                    while (true)
                    {
                       
                        Device.BeginInvokeOnMainThread(() =>
                        {
                            Needle1.Value = Val; // if I comment this line here RAM usage is normal
                            GaugeLabel.Text = Val.ToString("0.00");
                           
                        });
                        Thread.Sleep(500);
                    }

                }));
                t.Start();

Hi,

can i use the Zipfile Class from Windows Forms in xamarin forms ?

I need the extract method to unzip a file in a directory! if yes how can i include it ?

the ExtractToDirectory Method from .NET throw a IO Exception[Invalid Paramater] ! but it execute succesfully

Thanks in advance

Also posted here:

https://feedback.telerik.com/Project/168/Feedback/Details/258349-ios-datagrid-causes-nullreferenceexception-when-navigating-away

And here:

https://github.com/xamarin/Xamarin.Forms/issues/4178

Looks like there was a regression sometime between Xamarin.Forms 3.2.0.839982 and version 3.3.0.912540 with the DataGrid. After a DataGrid becomes visible on a page (or just on a page that becomes visible, even if the DataGrid itself is set to IsVisible = false), a NullReferenceException occurs if you navigate away or switch tabs in a RadTabView. Seems to only happen on iOS, and started happening when I upgraded from Xamarin.Forms from 3.2.0.839982 to version 3.3.0.912540. Possibly a Xamarin.Forms bug and not a Telerik bug.

In case anyone else has the same issue, the workaround for me is just to go back to Xamarin.Forms 3.2.0.839982 (not sure if the issue occurs in the other 3.2.* version in between). 

We have a list and by choosing a value, we hide some list items. The items become invisible, there is no problem but occupied places by items stay still after we set invisible. We use MVVM and this part works fine and we bind a property for IsVisible and it seems it works too. Only problem here, the list does not invalidate/refresh itself to re-arrange the view.

 I do not know why but I cannot attached the pictures..

So here is the my list

https://i.imgur.com/3wGJi3i.png

and here, after we made some invisible items..

https://i.imgur.com/SPzaE3s.png

I realize something.. After we set Invisible, the height of the custom control is still 37, and HeightRequest and MinimumHeightRequest are -1. I tried to change -1 to 0 but nothing changed.

Here is our listview Code and binding.,

Normally ListView from Xamarin.Forms has a property HasUnevenRows. I believe that It may work but RadListView has not this property.

Thank you in advance.

I am follow the documentation setting a theme. When I start debug the iOS Project, I got an exception:

Unhandled Exception:
Xamarin.Forms.Xaml.XamlParseException: Position 18:37. Type TelerikThemeStyles not found in xmlns clr-namespace:Telerik.XamarinForms.Chart;assembly=Telerik.XamarinForms.Chart

How do I fix this exception?

Hello, can anyone else confirm me that the RadCalendar has a bug on the height ?
(I'm using the CalendarViewMode.Week view mode)

Exemple : a Calendar inside a grid vs a calendar inside a stacklayout. With a row set to Auto, it should behave the same. But it seems that the Calendar is taking all the available height like if the row's height was a star instead of auto.

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>
    <ti:RadCalendar NativeControlLoaded="RadCalendar_NativeControlLoaded" Grid.Row="0" />
    <v:MeetingsDayInfoView  Grid.Row="1"/>
    <ListView BackgroundColor="LightSkyBlue" Grid.Row="2" />
</Grid>

<StackLayout>
    <ti:RadCalendar NativeControlLoaded="RadCalendar_NativeControlLoaded" />
    <v:MeetingsDayInfoView />
    <ListView BackgroundColor="LightSkyBlue" VerticalOptions="FillAndExpand" />
</StackLayout>

Finally, if I don't set the height of the calendar to HeightRequest="100", the calendar seems to keep the first height it had when loading the month CalendarViewMode.

When calling TrySetViewMode(CalendarViewMode.Week) from code behind, it should refresh the height IMHO.

I hate to set height and width on element which doesn't need. The height should be dynamic and depends on the label fontsize etc.

 I've attached a picture of the 3 behaviors.

Any suggestion would be nice.
Thanks !

Hello all together,

in my RadDataGrid I have a label as DataTemplate. I'm setting the labels text color according to it's binding value "IsSelected" to white or black. I works very well. It is the same solution as for highlighting a tree item in the RadTreeView https://www.telerik.com/forums/highlighting-selected-treeview-item

The problem is, the whole RadDataGrid is flickering when the labels text colors are changing after an item tap, and the RadTreeView is not.

What's the problem with RadDataGrid?

Thank you,

best regards

Martin

Xaml to highlight the selected RadDataGrid-Item:

Hello,

is there any possibility for setting rounded corners on the outer buttons on Android and UWP like seen on iOS?

From Telerik segmented control overview

here phone number 3:

From Telerik Docs

Thank you,

regards Martin

When I use RadCalendar in Xamarin forms in Simulator.

The error {System.Reflection.CustomAttributeFormatException: Could not find a property with name ParameterBlockProxy } pop up

I found that if I remove all Calendars in my app, it can work in Simulator.

But once I include it in Xamarin forms. The error exists.

Remarks: I can run the app in physical devices.

/Versions/11.12.0.4/src/Xamarin.iOS/Foundation/NSObject2.cs:497   at Foundation.NSObject..ctor (Foundation.NSObjectFlag x) [0x00006] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.12.0.4/src/Xamarin.iOS/Foundation/NSObject2.cs:116 

  at TelerikUI.TKCalendarDataSource..ctor () [0x00000] in <80266520e2ec48e69365daef99f55ad3>:0 
  at Telerik.XamarinForms.InputRenderer.iOS.CalendarAdapter.UpdateAppointmentsSource (Telerik.XamarinForms.Input.RadCalendar sourceOwner, TelerikUI.TKCalendar targetOwner, System.Boolean immediate) [0x0001c] in <0a8c5773e2e74216b75b8301a18ed2de>:0 
  at Telerik.XamarinForms.InputRenderer.iOS.CalendarAdapter.UpdateCore (Telerik.XamarinForms.Input.RadCalendar sourceOwner, TelerikUI.TKCalendar targetOwner, System.String propertyName) [0x00043] in <0a8c5773e2e74216b75b8301a18ed2de>:0 
  at Telerik.XamarinForms.Common.FacadeAdapterBase`2[S,T].Update (System.Object sourceOwner, System.Object targetOwner, System.String propertyName, System.Object sourceOwnerRoot, System.Object 
…

I want to show a content in the center of the indicator. I tried to manipulate the margin but did not work

<telerikBusyIndicator:RadBusyIndicator x:Name="BusyIndicator"
                                       AnimationContentHeightRequest="100"
                                       AnimationContentWidthRequest="100"
                                      AnimationType="Animation3"
                                       IsBusy="True">
                <telerikBusyIndicator:RadBusyIndicator.Content>
                    <Label Text="This is the content of the RadBusyIndicator control displayed when the indicator is not busy." TextColor="Black" />
                </telerikBusyIndicator:RadBusyIndicator.Content>
                <telerikBusyIndicator:RadBusyIndicator.BusyContent>
                    <Label HorizontalOptions="Center"
               Text="Loading..."
               VerticalOptions="Center"
                           Margin="0,0,0,50"/>
                </telerikBusyIndicator:RadBusyIndicator.BusyContent>
            </telerikBusyIndicator:RadBusyIndicator>

I actually want to show an image (filled) in the center of the indicator as follows: