代码之家 › 专栏 › 技术社区 › Lasse V. Karlsen

在中获取泛型类型的基名称的正确方法。NET是通过Substring吗?

types reflection .net c#

Lasse V. Karlsen · 技术社区 · 16 年前

如果我有这个:

Type t = typeof(Dictionary<String, String>);

"System.Collections.Generic.Dictionary"

String n = t.FullName.Substring(0, t.FullName.IndexOf("`"));

不过,在我看来,这有点老套。

Type 对象,并生成与C#源代码文件中的代码类似的代码。我正在生成一些文本模板,我需要将类型作为字符串添加到源代码中 FullName property产生类似这样的结果:

System.Collections.Generic.Dictionary`2[[System.String, mscorlib, Version=2.0.0.0,
Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.String, mscorlib, Version=2.0.0.0,
Culture=neutral, PublicKeyToken=b77a5c561934e089]]

而不是我想要的:

System.Collections.Generic.Dictionary<System.String, System.String>

编辑 :好的,这是最后的代码,对我来说仍然有点像黑客,但它有效:

/// <summary>
/// This method takes a type and produces a proper full type name for it, expanding generics properly.
/// </summary>
/// <param name="type">
/// The type to produce the full type name for.
/// </param>
/// <returns>
/// The type name for <paramref name="type"/> as a string.
/// </returns>
/// <exception cref="ArgumentNullException">
/// <para><paramref name="type"/> is <c>null</c>.</para>
/// </exception>
public static String TypeToString(Type type)
{
    #region Parameter Validation

    if (Object.ReferenceEquals(null, type))
        throw new ArgumentNullException("type");

    #endregion

    if (type.IsGenericType)
    {
        if (type.GetGenericTypeDefinition() == typeof(Nullable<>))
        {
            Type underlyingType = type.GetGenericArguments()[0];
            return String.Format("{0}?", TypeToString(underlyingType));
        }
        String baseName = type.FullName.Substring(0, type.FullName.IndexOf("`"));
        return baseName + "<" + String.Join(", ", (from paramType in type.GetGenericArguments()
                                                   select TypeToString(paramType)).ToArray()) + ">";
    }
    else
    {
        return type.FullName;
    }
}

4 回复 | 直到 10 年前

bobbymcr 16 年前

IL syntax:     [mscorlib]System.Collections.Generic.Dictionary`2<class [mscorlib]System.String, class [mscorlib]System.String>
C# syntax:     System.Collections.Generic.Dictionary<System.String, System.String>
VB.NET syntax: System.Collections.Generic.Dictionary(Of System.String, system.String)

也许你可以调用语言服务来获取你想要的字符串,但你可能更擅长自己生成字符串。

JohannesH 16 年前

您可以使用CodeDom生成一个看起来更“正常”的C#风格声明。

CodeDomProvider csharpProvider = CodeDomProvider.CreateProvider("C#");
CodeTypeReference typeReference = new CodeTypeReference(typeof(Dictionary<string, int>));
CodeVariableDeclarationStatement variableDeclaration = new CodeVariableDeclarationStatement(typeReference, "dummy");
StringBuilder sb = new StringBuilder();
using (StringWriter writer = new StringWriter(sb))
{
    csharpProvider.GenerateCodeFromStatement(variableDeclaration, writer, new CodeGeneratorOptions());
}

sb.Replace(" dummy;", null);
Console.WriteLine(sb.ToString());

System.Collections.Generic.Dictionary<string, int>

LukeH 16 年前

这更接近你想要的吗?

它使用 CodeTypeReferenceExpression Substring 或 Replace 电话:

var type = typeof(Dictionary<string, string>);
Console.WriteLine(TypeToString(type));

// ...

public static string TypeToString(Type type)
{
    if (type == null) throw new ArgumentNullException("type");

    var sb = new StringBuilder();
    using (var sw = new StringWriter(sb))
    {
        var expr = new CodeTypeReferenceExpression(type);

        var prov = new CSharpCodeProvider();
        prov.GenerateCodeFromExpression(expr, sw, new CodeGeneratorOptions());
    }
    return sb.ToString();
}

Brian Rasmussen 16 年前