Convert IEnumerable to string[]

Question

I have the code below, basically returns a single column of string values from a DB using MassiveORM.

The Query() method returns IEnumerable. I'm trying to find out how to cast or convert that to a simple string array.

Using the below I get

Unable to cast object of type 'System.Object[]' to type 'System.String[]

Thanks

var response = new MakesResponse();
var tbl = new DynamicModel("SONICAPI");
string sql = "EXEC pGetMakes";
var result = tbl.Query(sql);

return new MakesResponse()
{
makes = (string[])result.ToArray(),
ExecutionTime = sw.ElapsedMilliseconds,
Result = "200",
ResultText = "OK",
Source = "DB"
};

Do you know how to cast a single result to a string? – IS4 Jan 29 '18 at 12:36 — IS4, Jan 29 '18 at 12:36

score 10 · Answer 1 · edited Jan 29 '18 at 12:23

10

You can cast the enumerable items. This will only work if they are really string:

makes = result.Cast<string>().ToArray()

Else, you can call ToString, if there is a good implementation of it:

makes = result.Select(o => o.ToString()).ToArray()

edited Jan 29 '18 at 12:23

Camilo Terevinto

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answered Jan 29 '18 at 12:17

Patrick Hofman

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Hi, makes = result.Cast().ToArray() gives me Unable to cast object of type 'System.Dynamic.ExpandoObject' to type 'System.String' – Ben Jan 29 '18 at 12:32
@Ben Maybe your result containes types other than string as well, some nulls for example – rokkerboci Jan 29 '18 at 12:39
So maybe it doesn't contain a `string`, as you say, but rather an object of type `ExpandObject`. – Patrick Hofman Jan 29 '18 at 12:41
1

@Ben Try `result.Cast().Select(e => (string)((IDictionary)e).FirstOrDefault().Value).ToArray()`. – Patrick Hofman Jan 29 '18 at 12:43
Patrick, that gives me a collection of key/value pairs. The key is always "make" which is the db column name, the values are the string values i'm trying to access. – Ben Jan 29 '18 at 12:54
I updated the code just after I posted it. Can you retry please? – Patrick Hofman Jan 29 '18 at 12:54
@Ben Need more help? – Patrick Hofman Jan 29 '18 at 13:25
If you have no further questions, please accept the answer you deemed most helpful by checking the check mark before that answer. – Patrick Hofman Jan 29 '18 at 13:42

Convert IEnumerable to string[]

1 Answers1