我试图使用Visual Studio中的Xamarin.Forms实现Xamarin.Forms.CarouselView以便在iOS和Android上使用。它可以在Android上完美运行，但不能在iOS上运行。在iOS上，它显示了第一张幻灯片，但不允许我向右或向左滑动来更改当前幻灯片。我已经在iOS和Android项目中都安装了NuGet软件包。 XAML看起来像这样：
<cv:CarouselView ItemsSource="{Binding Slider}" x:Name="CarouselSlider">
<cv:CarouselView.ItemTemplate>
<DataTemplate>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
<!--<RowDefinition Height="Auto"/>-->
</Grid.RowDefinitions>
<Image Grid.RowSpan="1" Aspect="AspectFill" Source="{Binding ImageUrl}" />
<StackLayout BackgroundColor="#7F000000" Padding="12" VerticalOptions="Center" TranslationY="100">
<Label TextColor="White" Text="{Binding Title}" FontSize="26" HorizontalOptions="Center" VerticalOptions="CenterAndExpand"/>
<Label TextColor="White" Text="{Binding TextBody}" FontSize="16" HorizontalOptions="Center" HorizontalTextAlignment="Center" VerticalOptions="CenterAndExpand"/>
</StackLayout>
</Grid>
</DataTemplate>
</cv:CarouselView.ItemTemplate>
</cv:CarouselView>
后端看起来像这样：
public partial class MainPage : ContentPage
{
public System.Collections.ObjectModel.ObservableCollection<SliderContent> Slider { get; set; }
public MainPage()
{
InitializeComponent();
NavigationPage.SetHasNavigationBar(this, false);
Slider = new System.Collections.ObjectModel.ObservableCollection<SliderContent>
{
new SliderContent
{
Id = 1,
ImageUrl = "https://thumb9.shutterstock.com/display_pic_with_logo/1975943/561919966/stock-photo-brutal-strong-athletic-men-pumping-up-muscles-workout-bodybuilding-concept-background-muscular-561919966.jpg",
Title = "Aliquam et neque arcu",
TextBody = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nunc porttitor erat arcu, vitae accumsan odio iaculis et."
},
new SliderContent
{
Id = 2,
ImageUrl = "https://ifitlife.files.wordpress.com/2014/06/20140604-155437-57277345.jpg",
Title = "Donec lobortis sodales dui",
TextBody = "Morbi congue scelerisque vulputate. Vestibulum sit amet hendrerit justo. Nulla facilisi."
},
new SliderContent
{
Id = 3,
ImageUrl = "https://uproxx.files.wordpress.com/2013/05/dmx-black.jpg?quality=100&w=650",
Title = "Vestibulum arcu elit",
TextBody = "Aliquam in maximus ante. Suspendisse facilisis posuere nulla quis hendrerit. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas."
}
};
Grid dotsGrid = DotsIndicator;
dotsGrid.HorizontalOptions = LayoutOptions.CenterAndExpand;
dotsGrid.ColumnDefinitions = new ColumnDefinitionCollection
{
new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) },
new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) },
new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) }
};
dotsGrid.RowDefinitions = new RowDefinitionCollection
{
new RowDefinition { Height = new GridLength(6, GridUnitType.Star) },
new RowDefinition { Height = new GridLength(2, GridUnitType.Star) },
new RowDefinition { Height = new GridLength(6, GridUnitType.Star) }
};
int counter = 0;
foreach (var i in Slider)
{
Button label = new Button();
if (Slider.First() == i)
{
label = new Button
{
BackgroundColor = Color.White,
BindingContext = i,
VerticalOptions = LayoutOptions.Fill,
WidthRequest = 20,
HeightRequest = 20,
BorderRadius = 30
};
}
else
{
label = new Button
{
BackgroundColor = Color.Gray,
BindingContext = i,
VerticalOptions = LayoutOptions.Fill,
WidthRequest = 20,
HeightRequest = 20,
BorderRadius = 30
};
}
dotsGrid.Children.Add(label, counter, 1);
counter++;
}
DotsIndicator = dotsGrid;
this.BindingContext = this;
CarouselSlider.ItemSelected += CarouselSlider_ItemSelected;
}
private void CarouselSlider_ItemSelected(object sender, SelectedItemChangedEventArgs e)
{
var item = e.SelectedItem as SliderContent;
foreach (var i in DotsIndicator.Children)
{
i.BackgroundColor = Color.Gray;
if (i.BindingContext == item)
{
i.BackgroundColor = Color.White;
}
}
return;
}
}
在iOS上使用Xamarin.Forms.CarouselView是否存在任何已知问题，或者我缺少什么？
最佳答案
我已经将Xamarin.Forms CarouselView用于各种iOS项目，它工作正常。以下是我的示例代码，请参阅my blog以获取更多详细信息。希望能帮助到你。
将CarouselView Nuget软件包安装到所有项目（PCL，Android，iOS和Windows）
-由于CarouselView位于单独的程序集中，因此请在Xaml页面的根目录中添加CarouselView的命名空间，然后像这样在您的页面中使用它；
<?xml version="1.0" encoding="UTF-8"?>
<ContentView xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="XYZ.Mobile.App.Controls.ValidationControls.Confirmation"
xmlns:valueconverters="clr-namespace:XYZ.Mobile.App.ValueConverters"
xmlns:cv="clr-namespace:Xamarin.Forms;assembly=Xamarin.Forms.CarouselView">
<StackLayout Grid.Row="1"
Orientation="Vertical">
<cv:CarouselView x:Name="ConfirmationQuestionsCarousel"
ItemsSource="{Binding ConfirmationQuestions}">
<cv:CarouselView.ItemTemplate>
<DataTemplate>
<!--You can now add other Xamarin controls in to your CarouselView-->
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="50"/>
<RowDefinition/>
<RowDefinition Height="50"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<Label Grid.Row="0"
Grid.ColumnSpan="2"
Text="SOME TEXT"
FontAttributes="Bold" />
<Label Grid.Row="1"
Grid.ColumnSpan="2"
Text="{Binding Question}"/>
<Button Grid.Row="2"
Grid.Column="0"
Text="No"
StyleId="No"
CommandParameter="false"
Command="{Binding ToggleAgree}"
Clicked="OnQuestionAnswered"
BackgroundColor="{Binding Agreed, Converter={StaticResource BoolToToggleButtonColorConverter}, ConverterParameter='Invert'}"/>
<Button Grid.Row="2"
Grid.Column="1"
Text="Yes"
StyleId="Yes"
CommandParameter="true"
Command="{Binding ToggleAgree}"
Clicked="OnQuestionAnswered"
BackgroundColor="{Binding Agreed, Converter={StaticResource BoolToToggleButtonColorConverter}}"/>
</Grid>
</DataTemplate>
</cv:CarouselView.ItemTemplate>
</cv:CarouselView>
</StackLayout>
</ContentView>
此外;当我第一次使用Xamarin.Forms的CarouselView时，在获得CarouselView项的计数时遇到了一些问题。我需要此计数信息才能正确滑动到下一个项目。每当我尝试获取ConfirmationQuestionsCarousel.Count信息时，都会出现“未知成员”错误，因此最终我使用以下代码来获取计数信息。
private void OnQuestionAnswered(object sender, EventArgs args)
{
var buttonClicked = sender as Button;
var buttonClickedAnswer = buttonClicked.StyleId;
// Ugly way to get the count
//var s = new List<object>(ConfirmationQuestionsCarousel.ItemsSource.Cast<object>()).Count;
// Better way to get the count
int count = 0;
foreach (var item in ConfirmationQuestionsCarousel.ItemsSource)
{
count++;
}
// This is to set the Carosel's Position - this is unfinished code, I put it here only as an example
ConfirmationQuestionsCarousel.Position = 3;
}
关于c# - Xamarin.Forms.CarouselView在iOS上不起作用，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/44098638/