c# - 步骤类的 Specflow 容器尚未初始化

Question

public class BaseSteps : Steps
{
    [BeforeFeature]
    public static void BeforeFeatureStep()
    {
        var otherStep = new OtherStep();
        otherStep.ExecuteStep();
    }
} 

public class OtherStep : Steps
{
    public void ExecuteStep() 
    {
        var key = 'key';
        var val = 'val';
        this.FeatureContext.Add(key, val);
    }
}

这是一个示例片段。当我尝试访问 this.FeatureContext.Add() 时，出现异常，指出 Container of the steps class has not been initialized

感谢任何帮助。

Answer 1

FeatureContext 未初始化，因为 Step 类未由 SpecFlow DI 容器解析。因此不会调用 SetObjectContainer 方法 ( https://github.com/techtalk/SpecFlow/blob/master/TechTalk.SpecFlow/Steps.cs#L10 )。

作为一般规则，您不应自行实例化步骤类，而应通过上下文注入(inject) (http://specflow.org/documentation/Context-Injection) 获取它们。

但这在您的情况下是不可能的，因为您处于 BeforeFeature Hook 中。

一个可能的解决方案是，您使用最新的 SpecFlow 预发布版 (https://www.nuget.org/packages/SpecFlow/2.2.0-preview20170523)。在那里，您可以通过 Hook 方法中的参数获取 FeatureContext。它看起来像这样:

[BeforeFeature]
public static void BeforeFeatureHook(FeatureContext featureContext)
{
    //your code
}

您的代码可能如下所示:

public class FeatureContextDriver
{
    public void FeatureContextChanging(FeatureContext featureContext)
    {
        var key = 'key';
        var val = 'val';
        featureContext.Add(key, val);
    }
}

[Binding]
public class BaseSteps : Steps
{
    [BeforeFeature]
    public static void BeforeFeatureStep(FeatureContext featureContext)
    {
        var featureContextDriver = new FeatureContextDriver();
        featureContextDriver.FeatureContextChanging(featureContext);
    }
} 

[Binding]
public class OtherStep : Steps
{
    private FeatureContextDriver _featureContextDriver;
    public OtherStep(FeatureContextDriver featureContextDriver)
    {
        _featureContextDriver = featureContextDriver;
    }

    public void ExecuteStep() 
    {
        _featureContextDriver.FeatureContextChanging(this.FeatureContext);
    }
}

代码未经测试/试用并应用驱动程序模式。

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完全披露:我是 SpecFlow 和 SpecFlow+ 的维护者之一。