c#中的?.Invoke，即问号点Invoke

转自：https://hovertree.com/h/bjag/4dmf8x0u.htm

public delegate void OperateSuccessHanlder(string fileName); //创建委托
public event OperateSuccessHanlder OperateSuccess;
//UCPictureAdd.ascx.cs中的代码
void OnOperateSuccess(string fileName)
        {
            OperateSuccess?.Invoke(fileName);
        }

　　

上面代码等价于：

public delegate void OperateSuccessHanlder(string fileName); //创建委托
public event OperateSuccessHanlder OperateSuccess;
//UCPictureAdd.ascx.cs中的代码
void OnOperateSuccess(string fileName)
        {
           if(OperateSuccess!=null)
            {
                OperateSuccess(fileName);
            }
        }