/// <summary>
/// 检查委托的类型是否合法。
/// </summary>
/// <param name="type">委托的类型。</param>
/// <param name="paramName">参数的名称。</param>
internal static void CheckDelegateType(Type type, string paramName)
{
CommonExceptions.CheckArgumentNull(type, paramName);
Type baseType = type.BaseType;
if (baseType != typeof(MulticastDelegate))
{
throw CommonExceptions.MustBeDelegate(paramName);
}
}
/// <summary>
/// 创建指定对象中与默认指定相关的实例方法切换器，会自动推断关键参数（使用不同子类的参数，必须是唯一的）。
/// </summary>
/// <typeparam name="TDelegate">使用基类型调用方法的委托。</typeparam>
/// <param name="target">在其中查找实例方法的对象。</param>
/// <returns><paramref name="target"/> 中与默认标识相关的实例方法切换器。</returns>
/// <exception cref="ArgumentNullException"><paramref name="target"/> 为 <c>null</c>。</exception>
/// <exception cref="ArgumentException"><typeparamref name="TDelegate"/> 不是委托类型。</exception>
/// <exception cref="ArgumentException">委托类型与处理器不匹配。</exception>
/// <exception cref="ArgumentException">处理器的参数不匹配。</exception>
/// <exception cref="ArgumentException">没有找到唯一的关键参数。</exception>
public static TDelegate Create <TDelegate>(object target)
where TDelegate : class
{
if (target == null)
{
throw CommonExceptions.ArgumentNull("target");
}
Contract.Ensures(Contract.Result <TDelegate>() != null);
if (!typeof(TDelegate).IsSubclassOf(typeof(Delegate)))
{
throw CommonExceptions.MustBeDelegate("TDelegate", typeof(TDelegate));
}
ProcessorData data = GetMethods <TDelegate>(target.GetType(), ProcessorAttribute.DefaultId, false);
return(CreateSwitcher <TDelegate>(data, ProcessorAttribute.DefaultId, target));
}
/// <summary>
/// 创建指定对象中与标识指定相关的实例方法切换器，会自动推断关键参数（使用不同子类的参数，必须是唯一的）。
/// </summary>
/// <typeparam name="TDelegate">使用基类型调用方法的委托。</typeparam>
/// <param name="target">在其中查找实例方法的对象。</param>
/// <param name="id">处理器的标识。</param>
/// <returns><paramref name="target"/> 中与指定标识相关的实例方法切换器。</returns>
/// <exception cref="ArgumentNullException"><paramref name="target"/> 为 <c>null</c>。</exception>
/// <exception cref="ArgumentNullException"><paramref name="id"/> 为 <c>null</c>。</exception>
/// <exception cref="ArgumentException"><paramref name="id"/> 为空字符串。</exception>
/// <exception cref="ArgumentException"><typeparamref name="TDelegate"/> 不是委托类型。</exception>
/// <exception cref="ArgumentException">委托类型与处理器不匹配。</exception>
/// <exception cref="ArgumentException">处理器的参数不匹配。</exception>
/// <exception cref="ArgumentException">没有找到唯一的关键参数。</exception>
public static TDelegate Create <TDelegate>(object target, string id)
where TDelegate : class
{
if (target == null)
{
throw CommonExceptions.ArgumentNull("target");
}
if (string.IsNullOrEmpty(id))
{
throw CommonExceptions.StringEmpty("id");
}
Contract.Ensures(Contract.Result <TDelegate>() != null);
if (!typeof(TDelegate).IsSubclassOf(typeof(Delegate)))
{
throw CommonExceptions.MustBeDelegate("TDelegate", typeof(TDelegate));
}
ProcessorData data = GetMethods <TDelegate>(target.GetType(), id, false);
return(CreateSwitcher <TDelegate>(data, id, target));
}
/// <summary>
/// 创建与指定委托列表相关的方法切换器，会自动推断关键参数（使用不同子类的参数，必须是唯一的）。
/// </summary>
/// <typeparam name="TDelegate">使用基类型调用方法的委托类型。</typeparam>
/// <param name="delegates">使用不同子类作为参数的委托列表。</param>
/// <returns>与 <paramref name="delegates"/> 相关的方法切换器。</returns>
/// <exception cref="ArgumentNullException"><paramref name="delegates"/> 为 <c>null</c>。</exception>
/// <exception cref="ArgumentException"><paramref name="delegates"/> 中存在为 <c>null</c> 的委托。</exception>
/// <exception cref="ArgumentException"><typeparamref name="TDelegate"/> 不是委托类型。</exception>
/// <exception cref="ArgumentException">委托类型与处理器不匹配。</exception>
/// <exception cref="ArgumentException">处理器的参数不匹配。</exception>
/// <exception cref="ArgumentException">没有找到唯一的关键参数。</exception>
/// <overloads>
/// <summary>
/// 创建方法切换器，会自动推断关键参数（使用不同子类的参数，必须是唯一的）。
/// </summary>
/// </overloads>
public static TDelegate Create <TDelegate>(params Delegate[] delegates)
where TDelegate : class
{
if (delegates == null)
{
throw CommonExceptions.ArgumentNull("delegates");
}
if (delegates.Any(d => d == null))
{
throw CommonExceptions.CollectionItemNull("delegates");
}
Contract.Ensures(Contract.Result <TDelegate>() != null);
if (!typeof(TDelegate).IsSubclassOf(typeof(Delegate)))
{
throw CommonExceptions.MustBeDelegate("TDelegate", typeof(TDelegate));
}
ProcessorData data = new ProcessorData(delegates);
CheckDelegateType <TDelegate>(data);
return(CreateSwitcher <TDelegate>(data, null, null));
}