public class FileLoader
 {
  public delegate void FileLoadHandler(int progress);
  public FileLoadHandler FileLoaded;

  public void UpLoad()
  {
   int fileProgress = 100;
   while (fileProgress>0)
   {
    fileProgress--;
    if (FileLoaded!=null)
    {
     FileLoaded(fileProgress);
    }
   }
  }
 }

 public class TestFileLoader
 {
  public static void Run()
  {
   FileLoader fl = new FileLoader();
   fl.FileLoaded = Proress;

   fl.UpLoad();
   }

  //为何必须为static?
  private  void Proress(int progress)
  {
   Console.WriteLine(progress);
  }

如何方法Proress(int progress)不设置为static系统就报出：An object reference is required for the non-static field, method, or property?。这是什么原因？难不成是代理的对象引用必须为静态方法？