处理多个"Is"语句的方法

Question

在我当前的代码中,我正在使用if/else if&测试对象的类型is:

public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        if (value is double)
        {
            //do something
        }
        else if (value is int)
        {
            //do something
        }
        else if (value is string)
        {
            //do something
        }
        else if (value is bool)
        {
            //do something
        }
       Type type = value.GetType();
       throw new InvalidOperationException("Unsupported type [" + type.Name + "]");
    }

而不是一个长长的清单else if,我试图凝聚所有的is使用说明Extension Method,但无济于事.

这是我的尝试Extension Method:

public static class Extensions
    {
        public static bool Is<T>(this T t, params T[] values)
        {
            return values.Equals(t.GetType());
        }
    }

和方法:

public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        if (value is double)
        {
            //do something
        }
        else if (value.Is<object>(int, string, bool))
        {
            //do something
        }

        Type type = value.GetType();
        throw new InvalidOperationException("Unsupported type [" + type.Name + "]");
  }

有谁知道为什么会失败？任何帮助将不胜感激!

Answer 1

您需要传递类型,而不是类名.您还应该使用Contains而不是Equals:

public static bool IsAny(this object obj, params Type[] types)
{
    return types.Contains(obj.GetType());
}

if(value.IsAny(typeof(SolidColorBrush), typeof(LinearGradientBrush), typeof(GradientBrush), typeof(RadialGradientBrush)))
{
}

Contains完全匹配类型,因此您可能想要IsSubclassOf或IsAssignableFrom相反

例如

return types.Any(t => t.IsAssignableFrom(obj.GetType()));