在列表中选择与接口匹配的项目 [英] Select items in List that match an interface

问题描述

我定义了以下接口:

public interface IStep 
{
    string Name { get; set; }
}

public interface IStepBuildDataSet : IStep
{
    DataSet Data { get; set; }
}

public interface IStepBuildFile : IStep
{
    byte File { get; set; }
}

我有使用这些接口的代码:

I have code that uses these interfaces:

public List<IStep> Steps { get; set; }

public void RunJob()
{
  // pseudo code, need to update:
  IStepBuildDataSet buildDataSet = Steps.Single(s => s is IStepBuildDataSet);
  IStepBuildFile buildFile = Steps.Single(s => s is IStepBuildFile);

  // call methods on Steps
}

替换伪代码的正确语法是什么?我想从清单中获得实现certian接口的步骤.列表中只有一个.

What is the correct syntax for to replace the Pseudo Code? I want to get the step in the list that implements a certian interface. There will only be one of each in the list.

推荐答案

您可以使用OfType使其变得更加干净:

You could use OfType to make it abit cleaner like this:

IStepBuildDataSet buildDataSet = Steps.OfType<IStepBuildDataSet>().Single();
IStepBuildFile buildFile = Steps.OfType<IStepBuildFile>().Single();

请注意，由于OfType可以帮您实现结果，因此您无需投放结果.

Notice, you dont need to cast the results, since OfType does that for you.

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