使用C＃后端时，有什么方法可以加快将新元素添加到页面的速度？

Question

我有可以使用的代码，但是我发现创建页面元素的速度相当慢。

到目前为止，这就是我所拥有的。请注意，我并没有立即添加所有内容，因为我发现创建页面时甚至更慢。

    public void CreateSwitchSection(bool? selected)
    {
        Application.Current.Resources.TryGetValue("FrameBorder", out object frameBorder);
        var st = new StackLayout { Orientation = StackOrientation.Vertical, Spacing = 0 };
        st.Children.Add(AddSwitchRows(selected, App.cardSetWithWordCount.Take(20)));
        st.Children.Add(AddSwitchRows(selected, App.cardSetWithWordCount.Skip(20).Take(20)));
        st.Children.Add(AddSwitchRows(selected, App.cardSetWithWordCount.Skip(40).Take(20)));
        st.Children.Add(AddSwitchRows(selected, App.cardSetWithWordCount.Skip(60).Take(20)));
        st.Children.Add(AddSwitchRows(selected, App.cardSetWithWordCount.Skip(80).Take(20)));
        var fr = new Frame { Style = (Style)frameBorder };
        var fs = new FrameStack { };
        var ht = new HeaderTemplate()
        {
            Text = "CHOOSE CARD SETS FOR THE DECK"
        };
        fs.Children.Add(ht);
        fs.Children.Add(st);
        fs.Children.Add(new LineTemplate());
        fr.Content = fs;
        details.Children.Clear();
        details.Children.Add(fr);
    }

    private StackLayout AddSwitchRows(bool? selected, IEnumerable<CardSetWithWordCount> data)
    {
        var stack = new StackLayout
        {
            Orientation = StackOrientation.Vertical,
            Spacing = 0
        };

        foreach (var x in data)
        {
            var cell = new BadgeGridTemplate
            {
                BindingContext = x,
                Text = x.Name,
                State = selected == true ? "E" : "D",
                Message = x.TotalWordCount.ToString(),
                TapCommand = (Command)vm.SelectCardSetCmd,
                RowId = x.Id,
                Separator = true
            };
            stack.Children.Add(cell);
        }
        return stack;
    }

供参考的是我编写的BadgeGridTemplate：

<?xml version="1.0" encoding="UTF-8"?>
<t:BaseGridTemplate xmlns="http://xamarin.com/schemas/2014/forms" 
                    xmlns:t="clr-namespace:Japanese.Templates" 
                    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
                    xmlns:local="clr-namespace:Japanese;assembly=Japanese" 
                    xmlns:b="clr-namespace:Behaviors;assembly=Behaviors" 
                    xmlns:converters="clr-namespace:Japanese.Converters;assembly=Japanese" 
                    x:Class="Japanese.Templates.BadgeGridTemplate" 
                    x:Name="this" 
                    HeightRequest="{DynamicResource GridHeight}" Margin="0"
    Orientation="Vertical" Spacing="0">
    <BoxView HeightRequest="1" HorizontalOptions="FillAndExpand" IsVisible="{Binding Separator, Source={x:Reference this}}" BackgroundColor="{DynamicResource LineColor}" Margin="0" />
    <Grid Padding="20,0" VerticalOptions="CenterAndExpand">
        <Grid.ColumnDefinitions>
            <ColumnDefinition />
            <ColumnDefinition Width="Auto" />
        </Grid.ColumnDefinitions>
        <Label Grid.Column="0" Text="{Binding Text,  Source={x:Reference this}}" TextColor="{DynamicResource LabelColor}" Style="{StaticResource LabelText}" VerticalTextAlignment="Center" WidthRequest="30" />
        <t:Button Grid.Column="1" Meta="GsT" RowId="{Binding RowId, Source={x:Reference this}}" State="{Binding State, Source={x:Reference this}}" TapCommand="{Binding TapCommand, Source={x:Reference this}}" Text="{Binding Message, Source={x:Reference this}}" Theme="{Binding Theme}" WidthRequest="30" />
    </Grid>
</t:BaseGridTemplate>

Answer 1

如果顺序很重要，我还没有找到其他方法来做到这一点。如果顺序无关紧要，您可以将 StackLayout 拆分为多个 StackLayout，然后使用Task.WhenAll在异步线程中添加各个元素在异步线程中添加各个元素。

Task.WhenAll 就像让多个人同时为你工作，而不是只有 1 个人。