可访问性不一致:通用c#接口的参数类型

Question

我在VisualStudio中收到以下错误

可访问性不一致:参数类型'mynamespace.ProgressChangedEvent'比方法'mynamespace.StartScreen.ReceiveUpdate(mynamespace.ProgressChangedEvent)'更难访问

我的界面看起来像这样

public interface IObserver<T>
{
     void ReceiveUpdate(T ev);
}

我的Events类看起来像这样

namespace mynamespace
{
//The event interface
interface Event {}

//Concrete Event
class ProgressChangedEvent : Event
{
    private int fileCount = 0;
    private int filesProcessed = 0;

    public ProgressChangedEvent(int fileCount, int filesProcessed)
    {
        this.fileCount = fileCount;
        this.filesProcessed = filesProcessed;
    }

    public int FileCount
    {
        get{return fileCount;}
        set{fileCount = value;}
    }

    public int FilesProcessed
    {
        get { return filesProcessed; }
        set { filesProcessed = value; }
    }


    }
}

这个类是一个表单,它看起来像这样

namespace mynamespace
{
  public partial class StartScreen : Form, IObserver<ProgressChangedEvent>
  {


   /*
    * Lots of form code...
    */

    #region IObserver<ProgressChangedEvent> Members

    public void ReceiveUpdate(ProgressChangedEvent ev)
    {
        throw new Exception("The method or operation is not implemented.");
    }

    #endregion
    }


}

突出显示ReceiveUpdate方法,并显示上述错误.

Answer 1

你必须公开你的课程:

class ProgressChangedEvent : Event
{

应该

public class ProgressChangedEvent : Event
{

由于您的公共方法ReceiveUpdate()需要一个类型的变量ProgressChangedEvent,因此该类必须是公共的,因此它实际上可以被使用(来自程序集外部) - 这就是您得到该错误的原因.