一些我最好的方法扩展(我有很多!):
public static T ToEnum<T>(this string str) where T : struct
{
return (T)Enum.Parse(typeof(T), str);
}
//DayOfWeek sunday = "Sunday".ToEnum<DayOfWeek>();
public static string ToString<T>(this IEnumerable<T> collection, string separator)
{
return ToString(collection, t => t.ToString(), separator);
}
public static string ToString<T>(this IEnumerable<T> collection, Func<T, string> stringElement, string separator)
{
StringBuilder sb = new StringBuilder();
foreach (var item in collection)
{
sb.Append(stringElement(item));
sb.Append(separator);
}
return sb.ToString(0, Math.Max(0, sb.Length - separator.Length)); // quita el ultimo separador
}
//new []{1,2,3}.ToString(i=>i*2, ", ") --> "2, 4, 6"
此外，下一个意味着能够在几乎任何情况下继续在同一行中，而不是声明新变量然后删除状态:
public static R Map<T, R>(this T t, Func<T, R> func)
{
return func(t);
}
ExpensiveFindWally().Map(wally=>wally.FirstName + " " + wally.LastName)
public static R TryCC<T, R>(this T t, Func<T, R> func)
where T : class
where R : class
{
if (t == null) return null;
return func(t);
}
public static R? TryCS<T, R>(this T t, Func<T, R> func)
where T : class
where R : struct
{
if (t == null) return null;
return func(t);
}
public static R? TryCS<T, R>(this T t, Func<T, R?> func)
where T : class
where R : struct
{
if (t == null) return null;
return func(t);
}
public static R TrySC<T, R>(this T? t, Func<T, R> func)
where T : struct
where R : class
{
if (t == null) return null;
return func(t.Value);
}
public static R? TrySS<T, R>(this T? t, Func<T, R> func)
where T : struct
where R : struct
{
if (t == null) return null;
return func(t.Value);
}
public static R? TrySS<T, R>(this T? t, Func<T, R?> func)
where T : struct
where R : struct
{
if (t == null) return null;
return func(t.Value);
}
//int? bossNameLength = Departament.Boss.TryCC(b=>b.Name).TryCS(s=>s.Length);
public static T ThrowIfNullS<T>(this T? t, string mensaje)
where T : struct
{
if (t == null)
throw new NullReferenceException(mensaje);
return t.Value;
}
public static T ThrowIfNullC<T>(this T t, string mensaje)
where T : class
{
if (t == null)
throw new NullReferenceException(mensaje);
return t;
}
public static T Do<T>(this T t, Action<T> action)
{
action(t);
return t;
}
//Button b = new Button{Content = "Click"}.Do(b=>Canvas.SetColumn(b,2));
public static T TryDo<T>(this T t, Action<T> action) where T : class
{
if (t != null)
action(t);
return t;
}
public static T? TryDoS<T>(this T? t, Action<T> action) where T : struct
{
if (t != null)
action(t.Value);
return t;
}
希望它看起来不像来自火星:)
