.NETコアでconnectionString with PROVIDERを読み取る方法は？

Question

私はConnections.jsonが含まれてい

public Startup(IHostingEnvironment env) 

に

.AddJsonFile("Connections.json", optional: true, reloadOnChange: true) 

を追加しました：

public class ConnectionString 
{ 
    public string name { get; set; } 
    public string connectionString { get; set; } 
    public string providerName { get; set; } 
} 

トンのように：

{ 
    "ConnectionStrings": { 
    "DefaultConnection": "Server=(localdb)\\mssqllocaldb;Database=DATABASE;Trusted_Connection=True;MultipleActiveResultSets=true", 
    "COR-W81-101": "Data Source=DATASOURCE;Initial Catalog=P61_CAFM_Basic;User Id=USERID;Password=PASSWORD;Persist Security Info=False;MultipleActiveResultSets=False;Packet Size=4096;", 
    "COR-W81-100": "Data Source=DATASOURCE;Initial Catalog=Post_PS;User Id=USERID;Password=PASSWORD;Persist Security Info=False;MultipleActiveResultSets=False;Packet Size=4096;", 
    "MSEDGEWIN10": "Data Source=DATASOURCE; Initial Catalog=COR_Basic; Persist Security Info=False;Integrated Security=true;MultipleActiveResultSets=False;Packet Size=4096;Application Name=\"COR_Basic\"", 

    "server": "Data Source=DATASOURCE; Initial Catalog=COR_Basic; Persist Security Info=False;User Id=USERID;Password=PASSWORD;MultipleActiveResultSets=False;Packet Size=4096;Application Name=\"COR_Basic\"" 
    }, 


    "conStrings": [ 
     { 
     "name": "COR-W81-101",  
     "connectionString": "Data Source=DATASOURCE; Initial Catalog=COR_Basic; Persist Security Info=False;Integrated Security=true;MultipleActiveResultSets=False;Packet Size=4096;Application Name=\"COR_Basic\"", 
     "providerName": "System.Data.SqlClient" 
     } 

    }, 

    { 
     "name": "server", 
     "connectionString": "Data Source=DATASOURCE; Initial Catalog=COR_Basic; Persist Security Info=False;Integrated Security=true;MultipleActiveResultSets=False;Packet Size=4096;Application Name=\"COR_Basic\"", 
     "providerName": "System.Data.SqlClient" 
    } 
    ], 



    "conStringDictionary": { 
    "COR-W81-101": { 
     "connectionString": "Data Source=DATASOURCE; Initial Catalog=COR_Basic; Persist Security Info=False;Integrated Security=true;MultipleActiveResultSets=False;Packet Size=4096;Application Name=\"COR_Basic\"", 
     "providerName": "System.Data.SqlClient" 
    }, 

    "server": { 
     "connectionString": "Data Source=DATASOURCE; Initial Catalog=COR_Basic; Persist Security Info=False;Integrated Security=true;MultipleActiveResultSets=False;Packet Size=4096;Application Name=\"COR_Basic\"", 
     "providerName": "System.Data.SqlClient" 
    } 

    } 
} 

は、今私はのconnectionStringsを読みたいと思いました彼：

//Microsoft.Extensions.DependencyInjection.OptionsConfigurationServiceCollectionExtensions.Configure<ConnectionString[]>(services, Configuration.GetSection("conStrings")); 

// https://stackoverflow.com/questions/31929482/retrieve-sections-from-config-json-in-asp-net-5 
//var objectSections = Configuration.GetSection("conStringDictionary").GetChildren(); 
//foreach (var x in objectSections) 
//{ 
// System.Console.WriteLine(x.Key); 
// var cs = new ConnectionString(); 
// ConfigurationBinder.Bind(x, cs); 
// System.Console.WriteLine(cs); 
//} 

// http://andrewlock.net/how-to-use-the-ioptions-pattern-for-configuration-in-asp-net-core-rc2/ 
     Microsoft.Extensions.DependencyInjection.OptionsConfigurationServiceCollectionExtensions.Configure<Dictionary<string, ConnectionString>>(services, Configuration.GetSection("conStrings")); 

しかし、私はそれが配列または辞書を読むことができません。私は各connectionStringのproviderNameが必要です、そして、私は接続文字列と同じエントリでそれを持っているが、結合された文字列としては望んでいません。

Answer 1

、あなたがしなければならないすべては、古いConnectionStringSettingsに合わせて、いくつかの強く型付けされたクラスを作成し、いくつかのコレクションのシリアル化のロジックを使用しています。

jsonでフォーマットすることを提案します。むしろ、古いXML app/web.configのように接続文字列を指定する方法に似ています。キーとなる接続文字列の名前。

{ 
    "ConnectionStrings": { 
    "Test1": { 
     "ConnectionString": "server=localhost;database=db;username=user;password=pass;", 
     "ProviderName": "MySql.Data.MySqlClient" 
    }, 
    "Test2": { 
     "ConnectionString": "server=localhost;database=db2;username=user2;password=pass2;", 
     "ProviderName": "MySql.Data.MySqlClient" 
    } 
    } 
} 

ここでクラスをバインドします。最初は単純なConnectionStringSettingsクラスです。基本的な等価/ハッシングメソッドを実装しています（これをディクショナリに張り付けるために必要です）。

public class ConnectionStringSettings 
{ 
    public String Name { get; set; } 
    public String ConnectionString { get; set; } 
    public String ProviderName { get; set; } 

    public ConnectionStringSettings() 
    { 
    } 

    public ConnectionStringSettings(String name, String connectionString) 
     : this(name, connectionString, null) 
    { 
    } 

    public ConnectionStringSettings(String name, String connectionString, String providerName) 
    { 
     this.Name = name; 
     this.ConnectionString = connectionString; 
     this.ProviderName = providerName; 
    } 

    protected bool Equals(ConnectionStringSettings other) 
    { 
     return String.Equals(Name, other.Name) && String.Equals(ConnectionString, other.ConnectionString) && String.Equals(ProviderName, other.ProviderName); 
    } 

    public override bool Equals(Object obj) 
    { 
     if (ReferenceEquals(null, obj)) return false; 
     if (ReferenceEquals(this, obj)) return true; 
     if (obj.GetType() != this.GetType()) return false; 
     return Equals((ConnectionStringSettings) obj); 
    } 

    public override int GetHashCode() 
    { 
     unchecked 
     { 
      int hashCode = (Name != null ? Name.GetHashCode() : 0); 
      hashCode = (hashCode * 397)^(ConnectionString != null ? ConnectionString.GetHashCode() : 0); 
      hashCode = (hashCode * 397)^(ProviderName != null ? ProviderName.GetHashCode() : 0); 
      return hashCode; 
     } 
    } 

    public static bool operator ==(ConnectionStringSettings left, ConnectionStringSettings right) 
    { 
     return Equals(left, right); 
    } 

    public static bool operator !=(ConnectionStringSettings left, ConnectionStringSettings right) 
    { 
     return !Equals(left, right); 
    } 
} 

次は、ConnectionStringSettingsのコレクションです。これは、接続文字列の名前がJSON表記のキーであるためにのみ必要です。その名前を一貫して保持するためには、DictionaryのAddメソッドをオーバーライドする必要があります（ただし、仮想ではないのでできません）。だから私たちが本当にやっていることは、Dictionaryを内部的に私たち自身のAdd実装の余分なビットでラップすることだけです。これもコードのように見えますが、単調な退屈なものです。

public class ConnectionStringSettingsCollection : IDictionary<String, ConnectionStringSettings> 
{ 
    private readonly Dictionary<String, ConnectionStringSettings> m_ConnectionStrings; 

    public ConnectionStringSettingsCollection() 
    { 
     m_ConnectionStrings = new Dictionary<String, ConnectionStringSettings>(); 
    } 

    public ConnectionStringSettingsCollection(int capacity) 
    { 
     m_ConnectionStrings = new Dictionary<String, ConnectionStringSettings>(capacity); 
    } 

    #region IEnumerable methods 
    IEnumerator IEnumerable.GetEnumerator() 
    { 
     return ((IEnumerable)m_ConnectionStrings).GetEnumerator(); 
    } 
    #endregion 

    #region IEnumerable<> methods 
    IEnumerator<KeyValuePair<String, ConnectionStringSettings>> IEnumerable<KeyValuePair<String, ConnectionStringSettings>>.GetEnumerator() 
    { 
     return ((IEnumerable<KeyValuePair<String, ConnectionStringSettings>>)m_ConnectionStrings).GetEnumerator(); 
    } 
    #endregion 

    #region ICollection<> methods 
    void ICollection<KeyValuePair<String, ConnectionStringSettings>>.Add(KeyValuePair<String, ConnectionStringSettings> item) 
    { 
     ((ICollection<KeyValuePair<String, ConnectionStringSettings>>)m_ConnectionStrings).Add(item); 
    } 

    void ICollection<KeyValuePair<String, ConnectionStringSettings>>.Clear() 
    { 
     ((ICollection<KeyValuePair<String, ConnectionStringSettings>>)m_ConnectionStrings).Clear(); 
    } 

    Boolean ICollection<KeyValuePair<String, ConnectionStringSettings>>.Contains(KeyValuePair<String, ConnectionStringSettings> item) 
    { 
     return ((ICollection<KeyValuePair<String, ConnectionStringSettings>>)m_ConnectionStrings).Contains(item); 
    } 

    void ICollection<KeyValuePair<String, ConnectionStringSettings>>.CopyTo(KeyValuePair<String, ConnectionStringSettings>[] array, Int32 arrayIndex) 
    { 
     ((ICollection<KeyValuePair<String, ConnectionStringSettings>>)m_ConnectionStrings).CopyTo(array, arrayIndex); 
    } 

    Boolean ICollection<KeyValuePair<String, ConnectionStringSettings>>.Remove(KeyValuePair<String, ConnectionStringSettings> item) 
    { 
     return ((ICollection<KeyValuePair<String, ConnectionStringSettings>>)m_ConnectionStrings).Remove(item); 
    } 

    public Int32 Count => ((ICollection<KeyValuePair<String, ConnectionStringSettings>>)m_ConnectionStrings).Count; 
    public Boolean IsReadOnly => ((ICollection<KeyValuePair<String, ConnectionStringSettings>>)m_ConnectionStrings).IsReadOnly; 
    #endregion 

    #region IDictionary<> methods 
    public void Add(String key, ConnectionStringSettings value) 
    { 
     // NOTE only slight modification, we add back in the Name of connectionString here (since it is the key) 
     value.Name = key; 
     m_ConnectionStrings.Add(key, value); 
    } 

    public Boolean ContainsKey(String key) 
    { 
     return m_ConnectionStrings.ContainsKey(key); 
    } 

    public Boolean Remove(String key) 
    { 
     return m_ConnectionStrings.Remove(key); 
    } 

    public Boolean TryGetValue(String key, out ConnectionStringSettings value) 
    { 
     return m_ConnectionStrings.TryGetValue(key, out value); 
    } 

    public ConnectionStringSettings this[String key] 
    { 
     get => m_ConnectionStrings[key]; 
     set => Add(key, value); 
    } 

    public ICollection<String> Keys => m_ConnectionStrings.Keys; 
    public ICollection<ConnectionStringSettings> Values => m_ConnectionStrings.Values; 
    #endregion 
} 

物事を簡単にする簡単な拡張メソッドはいくつかあります。

public static class ConnectionStringSettingsExtensions 
{ 
    public static ConnectionStringSettingsCollection ConnectionStrings(this IConfigurationRoot configuration, String section = "ConnectionStrings") 
    { 
     var connectionStringCollection = configuration.GetSection(section).Get<ConnectionStringSettingsCollection>(); 
     if (connectionStringCollection == null) 
     { 
      return new ConnectionStringSettingsCollection(); 
     } 

     return connectionStringCollection; 
    } 

    public static ConnectionStringSettings ConnectionString(this IConfigurationRoot configuration, String name, String section = "ConnectionStrings") 
    { 
     ConnectionStringSettings connectionStringSettings; 

     var connectionStringCollection = configuration.GetSection(section).Get<ConnectionStringSettingsCollection>(); 
     if (connectionStringCollection == null || 
      !connectionStringCollection.TryGetValue(name, out connectionStringSettings)) 
     { 
      return null; 
     } 

     return connectionStringSettings; 
    } 
} 

最後に使用方法。

var configuration = new ConfigurationBuilder() 
    .AddJsonFile("config.json") 
    .Build(); 

var connectionStrings = configuration.ConnectionStrings(); 

foreach (var connectionString in connectionStrings.Values) 
{ 
    Console.WriteLine(connectionString.Name); 
    Console.WriteLine(connectionString.ConnectionString); 
    Console.WriteLine(connectionString.ProviderName); 
} 

var specificConnStr1 = connectionStrings["Test1"]; 
Console.WriteLine(specificConnStr1.Name); 
Console.WriteLine(specificConnStr1.ConnectionString); 
Console.WriteLine(specificConnStr1.ProviderName); 

var specificConnStr2 = configuration.ConnectionString("Test2"); 
Console.WriteLine(specificConnStr2.Name); 
Console.WriteLine(specificConnStr2.ConnectionString); 
Console.WriteLine(specificConnStr2.ProviderName); 

Answer 2

ような何か：あなたは基本的にありました

var configurationRoot = new ConfigurationBuilder() 
       .SetBasePath(Directory.GetCurrentDirectory()) 
       .AddJsonFile("appsettings.json", false) 
       .Build(); 

var conString = configurationRoot["ConnectionStrings:MyConnection"]);