I have an error that only showed up today. until yesterday it worked fine. in the meantime i have updated visual studio.
xamarin forms is 5.0
the error reports:
Java.Lang.IllegalStateException: 'The specified child already has a parent. You must call removeView () on the child's parent first. '
I have a scrollview which contains a variety of information (like whatsapp).
the information is contained inpublic ObservableCollection <FlowNote> FlowNoteList {get {return Get <ObservableCollection <FlowNote>> (); } set {Set (value); OnPropertyChanged (); }}
when I delete an element it generates the error.
FlowNote fn = FlowNoteList.SingleOrDefault (Predicate => Predicate.IdNota == idnote); FlowNoteList.Remove (fn);
except in case it is the last element ...
xaml è:
<ScrollView VerticalOptions="Start" Margin="0,0,0,50">
<StackLayout x:Name="FlowStackLayout" VerticalOptions="Start">
<ListView x:Name="FlowListView" ItemsSource="{Binding FlowNoteList}" IsVisible="True" HasUnevenRows="True" SeparatorVisibility="Default">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<SwipeView x:Name="swipView" SwipeStarted="SwipeView_SwipeStarted" SwipeEnded="SwipeView_SwipeEnded">
<SwipeView.LeftItems>
<SwipeItems>
<SwipeItem Text="Share"
BackgroundColor="#2196F3"
Invoked="OnShareSwipeItemInvoked" >
<SwipeItem.IconImageSource>
<FontImageSource Color="Black" Size="15" FontFamily="UserIcons" Glyph="{Static models:FontIconsClass.Share}"></FontImageSource>
</SwipeItem.IconImageSource>
</SwipeItem>
<SwipeItem Text="Edit" IsVisible="{Binding isMe, Converter={StaticResource isMeBoolInvertConverter}}"
BackgroundColor="#2196F3"
Invoked="OnEditNoteSwipeItemInvoked" >
<SwipeItem.IconImageSource>
<FontImageSource Color="Black" Size="15" FontFamily="UserIcons" Glyph="{Static models:FontIconsClass.CommentEdit}"></FontImageSource>
</SwipeItem.IconImageSource>
</SwipeItem>
</SwipeItems>
</SwipeView.LeftItems>
<SwipeView.RightItems>
<SwipeItems>
<SwipeItem Text="Delete" IsVisible="{Binding isMe, Converter={StaticResource isMeBoolInvertConverter}}"
BackgroundColor="#2196F3"
Command="{Binding Path=BindingContext.UserDeleteNotaCommand, Source={x:Reference FlowStackLayout}}" CommandParameter="{Binding IdNota}" >
<SwipeItem.IconImageSource>
<FontImageSource Color="Red" Size="15" FontFamily="UserIcons" Glyph="{Static models:FontIconsClass.Delete}"></FontImageSource>
</SwipeItem.IconImageSource>
</SwipeItem>
</SwipeItems>
</SwipeView.RightItems>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="40"/>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="40"/>
</Grid.ColumnDefinitions>
<Frame Style="{Binding isMe, Converter={StaticResource IntToFrameChatBackgroundConverter}}" Grid.Column="{Binding isMe}" Margin="5" Grid.ColumnSpan="2" >
<StackLayout Style="{Binding isMe, Converter={StaticResource IntToFrameChatBackgroundConverter}}" Grid.Column="{Binding isMe}" Margin="5" Grid.ColumnSpan="2" >
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
<ColumnDefinition Width="20"/>
</Grid.ColumnDefinitions>
<Label Text="{Binding User.Username}" TextColor="Black" IsVisible="{Binding isMe, Converter={StaticResource isMeBoolConverter}}" Margin="2" FontSize="12" HorizontalOptions="FillAndExpand" VerticalOptions="StartAndExpand"/>
<Label Text="{Binding Data, StringFormat=' {0:dd-MMM-yy HH:mm}'}" Grid.Column="1" TextColor="Black" Margin="2" FontSize="12" HorizontalOptions="EndAndExpand" VerticalOptions="StartAndExpand"/>
<Image Grid.Column="2" HorizontalOptions="Center">
<Image.GestureRecognizers>
<TapGestureRecognizer Tapped="RowMenu_tapped" CommandParameter="{Binding PathDoc}" NumberOfTapsRequired="1"></TapGestureRecognizer>
</Image.GestureRecognizers>
<Image.Source>
<FontImageSource Color="Black" Size="25" FontFamily="UserIcons" Glyph="{Static models:FontIconsClass.DotsVertical}"></FontImageSource>
</Image.Source>
</Image>
</Grid>
<Label Text="{Binding Titolo}" TextColor="Black" IsVisible="{Binding Titolo, Converter={StaticResource StringNullOrEmptyBoolConverter}}" Margin="2" FontAttributes="Bold" HorizontalOptions="FillAndExpand" VerticalOptions="StartAndExpand">
<Label.GestureRecognizers>
<TapGestureRecognizer Tapped="OnTitoloTapped" NumberOfTapsRequired="2"/>
</Label.GestureRecognizers>
</Label>
<Label Text="{Binding Nota}" LineBreakMode="WordWrap" TextColor="Black" IsVisible="{Binding Nota, Converter={StaticResource StringNullOrEmptyBoolConverter}}" Margin="2" HorizontalOptions="FillAndExpand" VerticalOptions="StartAndExpand">
<Label.GestureRecognizers>
<TapGestureRecognizer Tapped="OnEditNoteTapped" NumberOfTapsRequired="2"/>
</Label.GestureRecognizers>
</Label>
<Image IsVisible="{Binding AllegatoList, Converter={StaticResource ObservableCollectionMultipleBoolConverter}}" HorizontalOptions="Start">
<Image.Source>
<FontImageSource Color="Black" Size="25" FontFamily="UserIcons" Glyph="{Static models:FontIconsClass.Attachment}"></FontImageSource>
</Image.Source>
</Image>
<StackLayout x:Name="BindableLayoutAllegati" BindableLayout.ItemsSource="{Binding AllegatoList}">
<!--https://docs.microsoft.com/en-us/xamarin/xamarin-forms/user-interface/layouts/bindable-layouts-->
<BindableLayout.ItemTemplate>
<DataTemplate>
<StackLayout HorizontalOptions="CenterAndExpand">
<Grid IsVisible="{Binding PathDoc, Converter={StaticResource IsAudioValueConverter}}" HeightRequest="60">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="60"/>
<ColumnDefinition Width="150"/>
<ColumnDefinition Width="60"/>
</Grid.ColumnDefinitions>
<Image Source="{Binding Path=BindingContext.IconAudioPlayer, Source={x:Reference ImageAllegato}}" HeightRequest="50" WidthRequest="50" VerticalOptions="Center" HorizontalOptions="Center">
<Image.GestureRecognizers>
<TapGestureRecognizer Command="{Binding Path=BindingContext.PlayAudioCommand, Source={x:Reference ImageAllegato}}" CommandParameter="{Binding PathDoc}" NumberOfTapsRequired="1"></TapGestureRecognizer>
</Image.GestureRecognizers>
</Image>
<StackLayout Grid.Column="1">
<Label Text="{Binding TicksAudioPlayer}" TextColor="White" FontAttributes="Bold" HorizontalOptions="Center" />
<Slider x:Name="SliderSongPlayDisplay" Value="{Binding PositionAudioPlayer}" HorizontalOptions="FillAndExpand" Minimum="0" Maximum="{Binding DurationAudioPlayer}" MinimumTrackColor="{StaticResource Primary}" ThumbColor="{StaticResource Primary}" />
</StackLayout>
<Image Grid.Column="2" Source="{Binding PathDoc, Converter={StaticResource URLtoThumbValueConverter}}" HorizontalOptions="Center"/>
</Grid>
<!--<Label Text="{Binding Thumb}"/>-->
<!--<Image x:Name="ImageAllegato" Source="{Binding PathDoc, Converter={StaticResource URLtoThumbValueConverter}, ConverterParameter={Binding IsLinkWeb}}" HorizontalOptions="Center">-->
<!--<Label Text="{Binding NomeDoc}" TextColor="Black" IsVisible="{Binding NomeDoc, Converter={StaticResource StringNullOrEmptyBoolConverter}}" Margin="2" FontAttributes="Bold" HorizontalOptions="FillAndExpand" VerticalOptions="StartAndExpand"/>-->
<Image x:Name="ImageAllegato" HorizontalOptions="Center">
<Image.Source>
<MultiBinding Converter="{StaticResource URLtoThumbMultiValueConverter}">
<Binding Path="PathDoc" />
<Binding Path="IsLinkWeb" />
<Binding Path="Thumb" />
</MultiBinding>
</Image.Source>
<Image.Triggers>
<DataTrigger TargetType="Image" Binding="{Binding PathDoc, Converter={StaticResource IsAudioValueConverter}}" Value="True">
<Setter Property="IsVisible" Value="False" />
</DataTrigger>
</Image.Triggers>
<Image.GestureRecognizers>
<TapGestureRecognizer Command="{Binding Path=BindingContext.ZoomPhotoCommand, Source={x:Reference ImageAllegato}}" CommandParameter="{Binding PathDoc}" NumberOfTapsRequired="2"></TapGestureRecognizer>
</Image.GestureRecognizers>
</Image>
<Label Text="{Binding NoteDoc}" TextColor="Black" IsVisible="{Binding NoteDoc, Converter={StaticResource StringNullOrEmptyBoolConverter}}" Margin="2" FontAttributes="Bold" HorizontalOptions="FillAndExpand" VerticalOptions="StartAndExpand"/>
</StackLayout>
</DataTemplate>
</BindableLayout.ItemTemplate>
</StackLayout>
</StackLayout>
</Frame>
</Grid>
</SwipeView>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
</ScrollView>
(test on Android)
Thanks...