Xamarin.Forms iOS 依赖服务中的触觉反馈崩溃
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【中文标题】Xamarin.Forms iOS 依赖服务中的触觉反馈崩溃【英文标题】：Haptic Feedback crashes in Xamarin.Forms iOS Dependency Service 【发布时间】：2020-08-08 07:21:04 【问题描述】：我正在尝试在 Xamarin.Forms 应用程序中使用触觉反馈来通知用户选择更改。我找到了对 ios 的引用，并为 iOS 做了一个依赖服务；但是，它总是在没有任何 C# 错误的情况下崩溃。我试过在主线程和我正在使用的线程上调用它。它甚至在 try/catch 块中崩溃。这是我的代码：
using System;
namespace App.Services
public enum HapticFeedbackType
ImpactHeavy, // Heavy impact
ImpactMedium, // Medium impact
ImpactLight, // Light impact
Selection, // To tick while scrolling through a scrollview or carousel
NotificationError, // When an in-app error notification occurs
NotificationWarning, // When an in-app warning notification occurs
NotificationSuccess // When an in-app success notification occurs
public interface IHapticFeedback
void PrepareHapticFeedback(HapticFeedbackType type);
void ExecuteHapticFeedback(HapticFeedbackType type);
using System;
using UIKit;
using Xamarin.Forms;
using App.Services;
[assembly: Dependency(typeof(App.iOS.Services.HapticFeedbackService))]
namespace App.iOS.Services
public class HapticFeedbackService : IHapticFeedback
HapticFeedbackHelper helper;
public HapticFeedbackService()
helper = new HapticFeedbackHelper();
public void PrepareHapticFeedback(HapticFeedbackType type)
helper.PrepareHapticFeedback(type);
public void ExecuteHapticFeedback(HapticFeedbackType type)
helper.ExecuteHapticFeedback(type);
//https://blog.francois.raminosona.com/add-vibrations-in-a-xamarin-ios-app/
public class HapticFeedbackHelper: IDisposable
private UIImpactFeedbackGenerator _impactHeavyFeedbackGenerator;
private UIImpactFeedbackGenerator _impactMediumFeedbackGenerator;
private UIImpactFeedbackGenerator _impactLightFeedbackGenerator;
private UISelectionFeedbackGenerator _selectionFeedbackGenerator;
private UINotificationFeedbackGenerator _notificationFeedbackGenerator;
public HapticFeedbackHelper()
_impactHeavyFeedbackGenerator = new UIImpactFeedbackGenerator(UIImpactFeedbackStyle.Heavy);
_impactMediumFeedbackGenerator = new UIImpactFeedbackGenerator(UIImpactFeedbackStyle.Medium);
_impactLightFeedbackGenerator = new UIImpactFeedbackGenerator(UIImpactFeedbackStyle.Light);
_selectionFeedbackGenerator = new UISelectionFeedbackGenerator();
_notificationFeedbackGenerator = new UINotificationFeedbackGenerator();
public void PrepareHapticFeedback(HapticFeedbackType type)
switch (type)
case HapticFeedbackType.ImpactHeavy:
_impactHeavyFeedbackGenerator.Prepare();
break;
case HapticFeedbackType.ImpactMedium:
_impactMediumFeedbackGenerator.Prepare();
break;
case HapticFeedbackType.ImpactLight:
_impactLightFeedbackGenerator.Prepare();
break;
case HapticFeedbackType.Selection:
_selectionFeedbackGenerator.Prepare();
break;
case HapticFeedbackType.NotificationError:
case HapticFeedbackType.NotificationWarning:
case HapticFeedbackType.NotificationSuccess:
_notificationFeedbackGenerator.Prepare();
break;
public void ExecuteHapticFeedback(HapticFeedbackType type)
switch (type)
case HapticFeedbackType.ImpactHeavy:
_impactHeavyFeedbackGenerator.ImpactOccurred();
break;
case HapticFeedbackType.ImpactMedium:
_impactMediumFeedbackGenerator.ImpactOccurred();
break;
case HapticFeedbackType.ImpactLight:
_impactLightFeedbackGenerator.ImpactOccurred();
break;
case HapticFeedbackType.Selection:
_selectionFeedbackGenerator.SelectionChanged();
break;
case HapticFeedbackType.NotificationError:
_notificationFeedbackGenerator.NotificationOccurred(UINotificationFeedbackType.Error);
break;
case HapticFeedbackType.NotificationWarning:
_notificationFeedbackGenerator.NotificationOccurred(UINotificationFeedbackType.Warning);
break;
case HapticFeedbackType.NotificationSuccess:
_notificationFeedbackGenerator.NotificationOccurred(UINotificationFeedbackType.Success);
break;
#region IDisposable
public void Dispose()
_impactHeavyFeedbackGenerator = null;
_impactMediumFeedbackGenerator = null;
_impactLightFeedbackGenerator = null;
_selectionFeedbackGenerator = null;
_notificationFeedbackGenerator = null;
#endregion
async void LikeDown(object sender, MR.Gestures.DownUpEventArgs e)
LoggingController.Info("LikeDown event started...");
if (cancelReactionShowToken?.Token != null && cancelReactionShowToken.Token.CanBeCanceled)
cancelReactionShowToken.Cancel();
cancelReactionShowToken = new CancellationTokenSource();
Task task = new Task(async delegate
await Task.Delay(800);
if (cancelReactionShowToken.Token.IsCancellationRequested)
cancelReactionShowToken = null;
return;
MainThread.BeginInvokeOnMainThread(() =>
reactionPopup = new SfPopupLayout();
reactionPopup.PopupView.ShowHeader = false;
reactionPopup.PopupView.ShowFooter = false;
reactionPopup.PopupView.AutoSizeMode = AutoSizeMode.Both;
reactionPopup.PopupView.ContentTemplate = new DataTemplate(() =>
ReactionsView view = new ReactionsView();
this.Emojis = view.Emojis;
this.ReactionTypes = view.ReactionTypes;
return view;
);
reactionPopup.ShowRelativeToView(actionsRow, RelativePosition.AlignBottom, 0, 0);
try
hapticFeedback.ExecuteHapticFeedback(Services.HapticFeedbackType.Selection);
catch (Exception ex) Console.WriteLine(ex.Message);
//needs to be canceled so other guestures know
cancelReactionShowToken.Cancel();
, cancelReactionShowToken.Token);
task.Start();
await task;
如果有人对在 Xamarin.Forms 中使用触觉反馈有任何经验，那将会很有帮助。
【问题讨论】：
Xamarin Essentials 有一个振动库，可以满足您的需求。如果没有，您需要首先确定导致崩溃的行。 振动不起作用，因为它太强大了。触觉反馈是在选择器中使用的。它非常温和，并且有不同类型的振动。每当用户在图表上滑动手指或需要对某种次要事件的反馈时，都会调用它。振动适用于主要的事情，例如电话等 【参考方案1】：您需要放置一个异常捕获点并准确查看崩溃发生的位置。您已经放置了所有代码，很难弄清楚您在哪里搞砸了。它可能只是在一些不相关的东西中。您还应该分享您的应用程序输出，以显示异常是什么。
这是 ElysiumLab.com 的 Haptic 实现示例，他们还有一个 Nuget 包，可能已实现它以供使用“Naylah”：
在您的核心/表单项目中
public class HapticFeedback
public static IHapticFeedback Instance get; set;
static HapticFeedback()
Instance = new DefaultHapticFeedback();
internal class DefaultHapticFeedback : IHapticFeedback
public void Run(HapticFeedbackType hapticFeedbackType)
//This is a default thing should not be used;
//throw new System.Exception("Not initialized in device platforms isbrubles");
public interface IHapticFeedback
void Run(HapticFeedbackType hapticFeedbackType);
public enum HapticFeedbackType
Softy,
Medium,
Heavy
iOS 实现
public class HapticFeedbackService
public static void Init()
HapticFeedback.Instance = new iOSHapticFeedback();
public class iOSHapticFeedback : IHapticFeedback
public void Run(HapticFeedbackType hapticFeedbackType)
UIImpactFeedbackGenerator impact = null;
switch (hapticFeedbackType)
case HapticFeedbackType.Softy:
impact = new UIImpactFeedbackGenerator(UIImpactFeedbackStyle.Light);
break;
case HapticFeedbackType.Medium:
impact = new UIImpactFeedbackGenerator(UIImpactFeedbackStyle.Medium);
break;
case HapticFeedbackType.Heavy:
impact = new UIImpactFeedbackGenerator(UIImpactFeedbackStyle.Heavy);
break;
impact.Prepare();
impact.ImpactOccurred();
顺便说一句，您还可以像这样为 Haptic Feedback 创建一个 android 实现：
public class HapticFeedbackService
public static void Init(Activity activity)
HapticFeedback.Instance = new AndroidHapticFeedback(activity);
internal class AndroidHapticFeedback : IHapticFeedback
private readonly Activity activity;
public AndroidHapticFeedback(Activity activity)
this.activity = activity;
public void Run(HapticFeedbackType hapticFeedbackType)
switch (hapticFeedbackType)
case HapticFeedbackType.Softy:
activity.Window.DecorView.RootView.PerformHapticFeedback(FeedbackConstants.ContextClick);
break;
case HapticFeedbackType.Medium:
activity.Window.DecorView.RootView.PerformHapticFeedback(FeedbackConstants.KeyboardPress);
break;
case HapticFeedbackType.Heavy:
activity.Window.DecorView.RootView.PerformHapticFeedback(FeedbackConstants.KeyboardPress);
break;
您可以查看详细代码here，但如果您只是在寻找iOS实现，您可以查看here。
【讨论】：
我从博客中复制的实现和这相似，但使用它并没有崩溃。而且我无法粘贴应用程序输出，因为它在 VS 中没有给我任何信息，很可能是一些低级 iOS 系统错误。 嗯，奇怪。是的，它们非常相似，我很高兴它现在起作用了！以上是关于Xamarin.Forms iOS 依赖服务中的触觉反馈崩溃的主要内容，如果未能解决你的问题，请参考以下文章
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