Xamarin XamlParseException

Question

我尝试为Android发布时遇到此异常。我在构建iPhone版本时没有任何问题。

Xamarin.Forms.Xaml.XamlParseException: Position 10:5. Type convertor:NotConverter not found in xmlns clr-namespace:Comca.Helpers.Convertors;assembly=Comca.Helpers.Convertors

我试过了：

namespace:Comca;assembly=Comca.Helpers.Convertors 

和此：

namespace:Comca.Helpers.Convertors;assembly=Comca

继续在此处收到错误。

<?xml version="1.0" encoding="utf-8"?>
<Application xmlns="http://xamarin.com/schemas/2014/forms" 
    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
    xmlns:convertor="clr-namespace:Comca.Helpers.Convertors;assembly=Comca.Helpers.Convertors"
    x:Class="Comca.App">

这是班级：

using System;
using System.Globalization;
using Xamarin.Forms;

namespace Comca.Helpers.Convertors
{
public class NotConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return !(bool)value;
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return !(bool)value;
    }
  }
}

我完全迷失了。 谢谢你的帮助。