VS2013中C++/CLR的EventLog问题

代码如下

    EventLog log = gcnew EventLog();
    try
    {
        log.Source = "我的应用程序";
        log.WriteEntry("处理信息1", EventLogEntryType::Information);
        log.WriteEntry("处理信息2", EventLogEntryType::Information);
        throw gcnew System::IO::FileNotFoundException("readme.txt文件未找到");
    }
    catch (System::IO::FileNotFoundException ^exception)
    {
        log.WriteEntry("处理信息2", EventLogEntryType::Error);
    }

我这样写了后会报错：无法将参数 1 从“System::Diagnostics::EventLog ^”转换为“System::String ^”

就是那个EventLog log = gcnew EventLog();这里