I can't load data from json to tableview on xamarin - json

Question

I need your help.
UIViewControl....
var data= await track.QueryCategory(link);
if(data!=null)
{
var get_data=JsonConvert.DeserializeObject<Categorycs.RootObject>(data);
_table = new UITableView {
Frame = new CoreGraphics.CGRect (0, 0, View.Bounds.Width, View.Bounds.Height),
Source= new TableSoundCloudSource(get_data.tracks)
};
View.AddSubview (_table);
}
TableSource.cs
public class TableSource: UITableViewSource
{
List<string> tableItems;
string cellIdentifier="TableCell";
public TableSource (List<string> items)
{
tableItems = items;
}
public override nint RowsInSection(UITableView tableview, nint section)
{
return tableItems;
}
public override UITableViewCell GetCell (UITableView tableView, Foundation.NSIndexPath indexPath)
{
UITableViewCell cell = tableView.DequeueReusableCell (cellIdentifier);
if (cell == null) {
cell = new UITableViewCell (UITableViewCellStyle.Default, cellIdentifier);
} else
cell.TextLabel.Text = tableItems [indexPath.Row];
return cell;
}
}
}
Public class Categorycs
{
public class RootObject
{
public List<Track> tracks { get; set; }
public string tag { get; set; }
public string next_href { get; set; }
}
}
public class Track
{
public string urn { get; set; }
public string uri { get; set; }
public string permalink { get; set; }
public string permalink_url { get; set; }
public string title { get; set; }
public string description { get; set; }
public string track_type { get; set; }
public string genre { get; set; }
public string tag_list { get; set; }
public int duration { get; set; }
public bool? downloadable { get; set; }
public string download_url { get; set; }
public int original_content_size { get; set; }
public bool streamable { get; set; }
public bool commentable { get; set; }
public string sharing { get; set; }
public string created_at { get; set; }
public string updated_at { get; set; }
public string isrc { get; set; }
public string state { get; set; }
public int? likes_count { get; set; }
public int? playback_count { get; set; }
public int? reposts_count { get; set; }
public int? download_count { get; set; }
public int? comment_count { get; set; }
public string embeddable_by { get; set; }
public string license { get; set; }
public string artwork_url { get; set; }
public string stream_url { get; set; }
public string waveform_url { get; set; }
public string purchase_url { get; set; }
public string purchase_title { get; set; }
public bool reveal_comments { get; set; }
public bool reveal_stats { get; set; }
public bool feedable { get; set; }
public bool geo_blocking { get; set; }
public object geo_blockings { get; set; }
public bool embeddable { get; set; }
public string label_name { get; set; }
public string release_date { get; set; }
public object schedule { get; set; }
public Visuals visuals { get; set; }
public object publisher_metadata { get; set; }
public object monetization { get; set; }
public int user_id { get; set; }
public User user { get; set; }
public string policy { get; set; }
public string monetization_model { get; set; }
public object secret_token { get; set; }
public object secret_uri { get; set; }
public object publisher_state { get; set; }
public string last_modified { get; set; }
public object disabled_at { get; set; }
public object disabled_reason { get; set; }
public bool has_downloads_left { get; set; }
public string kind { get; set; }
public int id { get; set; }
}
Errors:Error CS1503: Argument #1' cannot
convertSystem.Collections.Generic.List<'Categorycs.Track'>' expression
to type `string[]'.
I have try to replaced 'List<'string'>'to List<'Categorycs.Track'> but app don't run.

Answer 1

here, you are passing TableSource get_data.tracks, which is a List<Track>:
Source= new TableSoundCloudSource(get_data.tracks)
but here, you are telling TableSource to accept a List<string>
public TableSource (List<string> items)
this is a "type mismatch" - it is expecting an object of Type A, but you are passing it an object of Type B. In some cases it can automatically convert A to B, but not in this case.
(I'm assuming that the fact that it is named "TableSoundCloudSource" in one place and "TableSource" in another is a cut-and-paste error. If not, then that is another problem with your code.)
You either need to modify your TableSource to accept a List<Track> (which will require several changes) or you need to pass it a List<string>, which is what it currently expects.
The 2nd error you're reporting is because of this:
public override nint RowsInSection(UITableView tableview, nint section)
{
return tableItems;
}
that function should return an nint, but you are returning tableItems, which is a List (it doesn't really matter what kind of list). What you really want to return is tableItems.Count, which is the number of elements in your list.
This code was always wrong, but because of the earlier problem the compiler probably never got to it to tell you it was bad. Debugging is like this - fixing one bug can uncover (or create) several more. You just have to slog through them until it works.
Finally,
cell.TextLabel.Text = tableItems [indexPath.Row];
Text is a string, tableItems[indexPath.Row] is a Track. You can't assign a Track to a string - that's another type mismatch. Instead, do this
cell.TextLabel.Text = tableItems [indexPath.Row].title;
Since the title property of Track is a string, that works (I'm assuming you want to use title - you can use any property that is a string, or can be automatically converted to a string)
Note that this really has nothing to do with Xamarin - it's basic C#, and conceptually basic programming.