Handle null for class's object

Jassim Al Rahma 1,556

Hi,

I have the following in my class which gets the data from my database:

public object application { get; set; }

The problem is that sometimes it's null and therefore the app will fail to run.

How can I handle the null here?

I tried:

public object? application { get; set; }

but it's not valid

Thanks,

P a u l 10,496 Reputation points

2022-01-16T22:42:29.9+00:00

Can you show us the logic that queries the DB/populates that field? What's the data type of the database column that this field maps to?

Jassim Al Rahma 1,556

This is the error:

System.Text.Json.JsonException: The JSON value could not be converted to System.Collections.Generic.List`1[Root]. Path: $ | LineNumber: 0 | BytePositionInLine: 1.

The code is:

var client = new HttpClient();  
  
client.Timeout = TimeSpan.FromSeconds(App.HttpClient_TimeOut);  
client.BaseAddress = new Uri("https://www.domain.com/go.php");  
  
var content = new FormUrlEncodedContent(new[]  
{  
    new KeyValuePair<string, string>("id", "x"),  
    new KeyValuePair<string, string>("user", "x")  
});  
  
var response = await client.PostAsync("https://www.domain.com/go.php", content);  
  
var result = await response.Content.ReadAsStringAsync();  
  
List<Root> data = JsonSerializer.Deserialize<List<Root>>(result);

The class is for Stripe result and it's attached as PDF because it's large to paste here..

165505-stripe-class.pdf

P a u l 10,496 Reputation points

2022-01-16T22:59:18.143+00:00

Mind posting the JSON / Root class?
Jassim Al Rahma 1,556 Reputation points

2022-01-16T23:00:50.597+00:00

Sorry, updated in my reply above.
P a u l 10,496 Reputation points

2022-01-16T23:07:10.957+00:00

It's worth copying the JSON to a local file, then stripping out properties to isolate the offending part. It's hard to help diagnose without seeing the JSON
Karen Payne MVP 35,386 Reputation points

2022-01-16T23:49:05.487+00:00

If this happens often and it's Deserialize which is throwing the exception, consider wrapping this in a try-catch, write the json to a log file then work backwards to the data in the database to see why there is an issue with the json.
Jassim Al Rahma 1,556 Reputation points

2022-01-17T09:25:12.073+00:00

Here is the JSON

165589-stripe-json.txt

1 answer

P a u l 10,496 Reputation points

2022-01-17T09:37:13.793+00:00
Try deserialising as Root rather than List<Root>:

Root data = JsonSerializer.Deserialize<Root>(result);
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1 person found this answer helpful.
Jassim Al Rahma 1,556 Reputation points

2022-01-18T20:48:27.393+00:00

Yes it's working. Thank you
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Handle null for class's object

1 answer