Question

I have the following method in public abstract A : IVirtualMachineExporter :

public override void Prepare() { ... }

I call the Prepare from another class B:

public sealed class B
{
    public new ExportJobRequest Request { get { return (ExportJobRequest)base.Request; } }

     private void ExportTask()
     {
          IVirtualMachineExporter exporter = CreateExporter();
          exporter.Prepare();
     }
}

Request containing public bool isAdHoc { get; set; }. I want to use information from this property inside Prepare(). How can I do this? I don't want to change Prepare() signature.

Answer 1

如何在不更改准备签名的情况下执行此操作？

嗯，某种程度上 Prepare需要一个实例来调用isAdHoc，所以如果你不想改变方法签名，您可以更改类或界面吗？

类似的东西：

      IVirtualMachineExporter exporter = CreateExporter(Request);
      exporter.Prepare();

或

      IVirtualMachineExporter exporter = CreateExporter();
      exporter.Request = Request;
      exporter.Prepare();

Answer 2

在A类中，公开一个公共属性IsAdhoc。

在从B类调用Prepare之前，在A类上设置IsAdhoc属性。

因此...

A类

public bool IsAdhoc { get; set; }

// Inside this method, do something based on the IsAdhoc property above.
public override void Prepare() { ... }

B类

public sealed class B
{
    public new ExportJobRequest Request { get { return (ExportJobRequest)base.Request; } }

     private void ExportTask()
     {
          IVirtualMachineExporter exporter = CreateExporter();
          exporter.IsAdhoc = this.Request.isAdhoc;
          exporter.Prepare();
     }
}

或者，您可以将布尔值传递给CreateExporter方法，该方法可以通过其构造函数在新的导出器类上设置它。

Answer 3

看起来B取决于IVirtualMachineExporter，而IVirtualMachineExporter（A）的实施取决于Request。 B不应该对A或它所依赖的内容有所了解。它应该只关心IVirtualMachineExporter接口并调用Prepare()。

您可以像这样创建：

public abstract class A : IVirtualMachineExporter
{
    private readonly ExportJobRequest _request;

    public A(ExportJobRequest request)
    {
        _request = request;
    }

    public override void Prepare()
    {
        //Now Prepare() has access to the Request because
        //it's contained within A, the class that actually needs it.
    }
}

同样，将接口（不是具体实现）传递给B。

的构造函数

public sealed class B
{
    private readonly IVirtualMachineExporter _exporter;

    public B(IVirtualMachineExporter exporter)
    {
        _exporter = exporter;
    }

    private void ExportTask()
    {
       //Can this isAdhoc property be a property of IVirtualMachineExporter,
       //or can the Request be a property? Will every implementation of the
       //interface have a request?

       //exporter.IsAdhoc = this.Request.isAdhoc;
       _exporter.Prepare();
    }
}

我没有你的设计细节。但是如果B将依赖于接口（IVirtualMachineExplorer），那么它不应该知道或关心任何实现接口的类的任何内部细节。

How to use data from one class into another?

3 个答案: