在 Xamarin.Forms 中以正确的文件类型打开字符串

Question

在我正在编写的应用程序中，我下载了一个文件作为字符串。我有文件名和扩展名，所以我知道它是什么类型的文件，但它被下载为一串wingdings等。如何将其转换为正确的类型并在 Android 上打开？

我正在使用 C# 在 Xamarin 表单中编写应用程序。在 iOS 中做这件事有很大不同吗？

    async void OnItemSelected(object sender, SelectedItemChangedEventArgs e)
    {
        Publication p = (Publication)e.SelectedItem;
        Debug.WriteLine(p);
        if (p.folderID.Equals("-1"))
        {
            string resp = await post(p.docNum);
            //Downloaded file is "resp"
            //Open file here, could be pdf, etc. Filename and extension are 
            //properties of Publication "p"

        } else
        {
            await Navigation.PushAsync(new PublicationsPage(p.folderID));
        }
    }


    private async Task<String> post(string id)
    {
        Dictionary<string, string> dir = new Dictionary<string, string>();
        dir.Add("LoginID", App.user.login_id);
        dir.Add("docID", id);
        var jsonReq = JsonConvert.SerializeObject(dir);
        Debug.WriteLine("req: " + (String)jsonReq);
        var content = new StringContent(jsonReq, Encoding.UTF8, "application/json");
        var response = await client.PostAsync("urlLink.com", content);
        var responseString = await response.Content.ReadAsStringAsync();
        return responseString;
    }

Answer 1

Deserialize:

var myObject = new MyType();
var ms = new MemoryStream(Encoding.UTF8.GetBytes(resp));
var ser = new DataContractJsonSerializer(myObject.GetType());
myObject = ser.ReadObject(ms) as MyType;
ms.Dispose();

超出范围：定义 MyType 并“打开”myObject。