我可以在Xamarin，C＃，iOS中保存文件对象数组（或json数组，字典数组）吗？

I have a list of "app" objects that I would like to save to file and retrieve later. I got to save each object to file using "File.AppendAllText(filename, son)" but when retrieving the file it is throwing an exception below:I have a list of "app" objects that I would lik