CODEWITHSUNDEEP
c#androidjsonxamarinxamarin.android
user5677145
user5677145

Reputation:

Cannot write JSON to file (Xamarin C#)

I try to write JSON to file like this:

string url2 = "http://papajohn.pp.ua/?mkapi=getProductsByCat&cat_id=83";
JsonValue json = await FetchAsync(url2);

var path = System.Environment.GetFolderPath(
    System.Environment.SpecialFolder.ApplicationData);
var filename = Path.Combine(path, "cache.txt");

File.WriteAllText(filename, json);

public async Task<JsonValue> FetchAsync(string url)
{
    System.IO.Stream jsonStream;
    JsonValue jsonDoc;

    using (var httpClient = new System.Net.Http.HttpClient())
    {
        jsonStream = await httpClient.GetStreamAsync(url);
        jsonDoc = JsonObject.Load(jsonStream);
    }

    return jsonDoc;
}

When I debug I the an error ...

System.InvalidCastException: Specified cast is not valid.

... in this line:

File.WriteAllText(filename, json);

Where is my mistake?

Upvotes: 2

Views: 814

Answers (1)

Sreeraj
Sreeraj

Reputation: 2434

Snippet to Get JsonString From the URL

public async Task<string> FetchAsync(string url)
    {
        string jsonString;

        using (var httpClient = new System.Net.Http.HttpClient())
        {
            var stream = await httpClient.GetStreamAsync(url);
            StreamReader reader = new StreamReader(stream);
            jsonString = reader.ReadToEnd();
        }

        return jsonString;
    }

Snippet to Invoke the above method and Save the String to Local File.

string url2 = "http://papajohn.pp.ua/?mkapi=getProductsByCat&cat_id=83";
            var json = await FetchAsync(url2);

            var path = System.Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
            var filename = Path.Combine(path, "cache.txt");
            File.WriteAllText(filename,json);

Snippet to later read that JsonString from that file and convert it to Json

JsonValue readJson; 
            var jsonString =File.ReadAllText(filename);
            readJson = JsonObject.Parse(jsonString);

Upvotes: 1

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