ジェネリックインターフェイスの制約

Question

は、私は次のコードを削減しようとしている

public interface IQuestion<TSite> : IShallowPost 
    where TSite : INetworkSite<TStyling, TRelation> 
    where TStyling : INetworkSiteStyling 
    where TRelation : INetworkSiteRelation 
{ 

がどのように私はその仕事を行うことができますか？このような何か持っているので

：

internal sealed class Question : IQuestion<NetworkSite, NetworkSiteStyling, NetworkSiteRelation> 

は、私には非常にほとんど意味がない

internal sealed class Question : IQuestion<NetworkSite> 

に比べて更新@Jared

確かに、これはそれだろう。

/// <summary> 
/// Represents a question on one of the Stack Exchange sites. 
/// <para>https://api.stackexchange.com/docs/types/question</para> 
/// </summary> 
/// <typeparam name="TSite">The concrete type of <see cref="INetworkSite{TStyling,TRelation}"/>.</typeparam> 
/// /// <typeparam name="TStyling">The concrete type of <see cref="INetworkSiteStyling"/>.</typeparam> 
/// <typeparam name="TRelation">The concrete type of <see cref="INetworkSiteRelation"/>.</typeparam> 
/// <typeparam name="TMigrationInfo">The concrete type of <see cref="IMigrationInfo{TSite,TStyling,TRelation}"/>.</typeparam> 
/// <typeparam name="TShallowUser">The concrete type of <see cref="IShallowUser"/>.</typeparam> 
/// <typeparam name="TComment">The concrete type of <see cref="IComment{TShallowUser}"/>.</typeparam> 
/// <typeparam name="TAnswer">The concrete type of <see cref="IAnswer{TShallowUser,TComment}"/>.</typeparam> 
public interface IQuestion<TShallowUser, TComment, TMigrationInfo, TSite, TStyling, TRelation, TAnswer> : IShallowPost<TShallowUser, TComment> 
    where TShallowUser : IShallowUser 
    where TComment : IComment<TShallowUser> 
    where TSite : INetworkSite<TStyling, TRelation> 
    where TStyling : INetworkSiteStyling 
    where TRelation : INetworkSiteRelation 
    where TMigrationInfo : IMigrationInfo<TSite, TStyling, TRelation> 
    where TAnswer : IAnswer<TShallowUser, TComment> 
{ 
    /// <summary> 
    /// The id of this question. 
    /// </summary> 
    [JsonProperty("question_id")] 
    long? QuestionId { get; set; } 
    /// <summary> 
    /// The date this question was locked. 
    /// </summary> 
    [JsonConverter(typeof(UnixDateTimeConverter))] 
    [JsonProperty("locked_date")] 
    DateTime? LockedDate { get; set; } 
    /// <summary> 
    /// The date this question was marked as community wiki. 
    /// </summary> 
    [JsonConverter(typeof(UnixDateTimeConverter))] 
    [JsonProperty("community_owned_date")] 
    DateTime? CommunityOwnedDate { get; set; } 
    /// <summary> 
    /// The amount of answers posted in response to this question. 
    /// </summary> 
    [JsonProperty("answer_count")] 
    long? AnswerCount { get; set; } 
    /// <summary> 
    /// The id of the accepted answer, if any. 
    /// </summary> 
    [JsonProperty("accepted_answer_id")] 
    long? AcceptedAnswerId { get; set; } 
    /// <summary> 
    /// Migration info telling where this question was migrated to. 
    /// </summary> 
    [JsonProperty("migrated_to")] 
    TMigrationInfo MigratedTo { get; set; } 
    /// <summary> 
    /// Migration info telling where this question was migrated from. 
    /// </summary> 
    [JsonProperty("migrated_from")] 
    TMigrationInfo MigratedFrom { get; set; } 
    /// <summary> 
    /// Date when the active bounty on this question ends. 
    /// </summary> 
    [JsonConverter(typeof(UnixDateTimeConverter))] 
    [JsonProperty("bounty_closes_date")] 
    DateTime? BountyClosesDate { get; set; } 
    /// <summary> 
    /// The amount of reputation spent on the bounty. 
    /// </summary> 
    [JsonProperty("bounty_amount ")] 
    long? BountyAmount { get; set; } 
    /// <summary> 
    /// The date this question was closed. 
    /// </summary> 
    [JsonConverter(typeof(UnixDateTimeConverter))] 
    [JsonProperty("closed_date")] 
    DateTime? ClosedDate { get; set; } 
    /// <summary> 
    /// The date this question was marked as protected. 
    /// </summary> 
    [JsonConverter(typeof(UnixDateTimeConverter))] 
    [JsonProperty("protected_date")] 
    DateTime? ProtectedDate { get; set; } 
    /// <summary> 
    /// The title of this question. 
    /// </summary> 
    [JsonProperty("title")] 
    string Title { get; set; } 
    /// <summary> 
    /// A list of tags applied on this question. 
    /// </summary> 
    [JsonProperty("tags")] 
    IList<string> Tags { get; set; } 
    /// <summary> 
    /// The reason this post was closed. 
    /// </summary> 
    [JsonProperty("closed_reason")] 
    string ClosedReason { get; set; } 
    /// <summary> 
    /// The amount of users who favorited this question. 
    /// </summary> 
    [JsonProperty("favorite_count")] 
    long? FavoriteCount { get; set; } 
    /// <summary> 
    /// The amount of views this question had. 
    /// </summary> 
    [JsonProperty("view_count")] 
    long? ViewCount { get; set; } 
    /// <summary> 
    /// A list of answers posted on this question. 
    /// </summary> 
    [JsonProperty("answers")] 
    IList<TAnswer> Answers { get; set; } 
    /// <summary> 
    /// A link to the question. 
    /// </summary> 
    [JsonProperty("link")] 
    string Link { get; set; } 
    /// <summary> 
    /// A boolean indicating whether this question is answered or considered unanswered. 
    /// </summary> 
    [JsonProperty("is_answered")] 
    bool? IsAnswered { get; set; } 
} 

ため、私はJSONデシリアライズの具体的な種類の代わりのインタフェースを必要とするが、私は本当に、これらの巨大なジェネリック型リストの周囲を通過する必要が嫌い。それは醜いです。

Answer 1

あなたは上記のC＃4またはを使用している場合はその制約を短くすると共変としてINetworkSiteの両方の型パラメータを宣言し、あなたのインターフェイスは次のように見えるようになることができます。

public interface IQuestion<TSite> : IShallowPost 
    where TSite : INetworkSite<INetworkSiteStyling, INetworkSiteRelation> 
{ 
    // interface members 
} 

public interface INetworkSite<out TStyling, out TRelation> 
    // these constraints are not actually needed for the example to work, 
    // but they seemed logical, so I left them in 
    where TStyling : INetworkSiteStyling 
    where TRelation : INetworkSiteRelation 
{ 
    // interface members 
} 

しかし、INetworkSiteは、任意の種類を必要とする場合指定された型（メソッドパラメータ、refパラメータ、設定可能なプロパティ）の入力の場合、これは機能しません。そのため、制約をそのまま残しておく必要があります。

もちろん、1つの型パラメータのみを共変変数として定義することは可能であり、そのうちの1つだけを制約から除外することができます。