C#代码-----------------------------------------------------------------

   [ComVisible(true)]
   [ClassInterface(ClassInterfaceType.AutoDual)]
   [ProgId("HelloWorld.MyClass")] //类名

   public class MyClass
   {
       public string UserName { get; set; } //对外提供属性

       public string SayHello(string content) //对外提供方法
       {
           return "用户:" + this.UserName  + "说:" + content;
       }
   }

Visaul Studio项目属性设置----------------------------------------

PowerBuilder代码-----------------------------------------------------------------

long ll_status
string ls_errorinfo, ls_ret
OLEObject myobj

if not isvalid(myobj) then
    myobj = CREATE OLEObject
end if

ll_status = myobj.connecttonewobject("HelloWorld.MyClass")

IF ll_status <> 0 THEN return

myobj.UserName = ‘张三‘
ls_ret = myobj.SayHello("哈哈")
Messagebox(‘提示‘,ls_ret)

PowerBuilder调用.Net编译好的DLL