Question

关于如何更好地编码，我有点不知所措。使用反射来获得样本背景上的Create<T>是可怕的。可悲的是，CreateAnonymous被弃用了......所以我无法想出更好的方法。

IX是一个接口，标本构建器正在创建实现IX的具体类的随机实例，以便进行测试。

/// <summary>
/// A specimen builder that creates random X messages.
/// </summary>
public class XMessageBuilder : ISpecimenBuilder
{
    // for brevity assume this has types implementing IX
    private readonly Type[] types;
    private readonly Random random = new Random();

    // THERE MUST BE A BETTER WAY TO DO THIS?
    // CreateAnonymous is deprecated :-(
    public IX CreateSampleMessage(ISpecimenContext context)
    {
        var rm = this.types.ElementAt(this.random.Next(0, this.types.Length));
        var method = typeof(SpecimenFactory).GetMethod("Create", new[] { typeof(ISpecimenContext) });
        var generic = method.MakeGenericMethod(rm);
        var instance = generic.Invoke(null, new object[] { context });
        return (IX)instance;
    }

    public object Create(object request, ISpecimenContext context)
    {
        var parameter = request as ParameterInfo;
        if (parameter == null)
            return new NoSpecimen();

        if (parameter.ParameterType == typeof(IX))
            return this.CreateSampleMessage(context);

        if (parameter.ParameterType == typeof(IX[]))
        {
            var array = new IX[10];
            for (int index = 0; index < array.Length; index++)
                array[index] = this.CreateSampleMessage(context);
            return array;
        }

        return new NoSpecimen();
    }

Answer 1

这样的事情应该有效：

public IX CreateSampleMessage(ISpecimenContext context)
{
    var rm = this.types.ElementAt(this.random.Next(0, this.types.Length));
    return (IX)context.Resolve(rm);
}

（虽然我没有尝试编译并运行一个repro，所以我可能在某个地方犯了错误。）

AutoFixture：如何使用ISpecimenBuilder创建多态对象

1 个答案: