convert system.data.linq.binary to byte[]

Question

I am storing bytes in a database table. When I retrieve it with Linq 2 sql I get the return type in system.data.linq.Binary.

I am not able to convert the system.data.linq.binary to byte array(byte[]).

How do I convert it?

///my datacontext

var db = new db();

//key is an value from user

var img = from i in db.images
          where i.id == key
          select i.data; 

the i.data is in linq.binary I want it to be in byte[].

I tried with (byte[])img but it did not work.

Solution 1

Have you tried calling ToArray() on i.data?

var img = from i in db.images
      where i.id == key
      select i.data.ToArray();

System.Data.Linq.Binary has a ToArray method just for that purpose.

Solution 2

Probably its too late by now but may help others :)

//testTable PK:ID, binaryData :binary(32)

public void insertDummyData()
{
    DBML.testTable v = new DBML.testTable ();
    v.ID = 1;

    System.Text.UTF8Encoding encoding = new System.Text.UTF8Encoding();
    v.binaryData = new System.Data.Linq.Binary(encoding.GetBytes("11111111000000001111111100000000"));                                                                    

    db.testTable.InsertOnSubmit(v);
    db.SubmitChanges();
}

Or else, Click on the Binary field from .dbml file, open properties and then change the field type from Binary to byte[] as found here

Solution 3

(byte[])linqBinaryField.ToArray()

Comments

[user1797079]

nope dude dosent wrk i am using linq to sql to "retrieve" the value and read it into byte array conversion is from System.Data.Linq.Binary to System.byte[]

[user1797079]

ya it dosent work man it returns System.Data.Linq.Binary[] the array of binary thats it :(

[user1797079]

plus we hav to use it as var img = (from i in db.images where i.id == key select i.data).ToArray();

[Mike Two]

The ToArray() call has to be on i.data. You are putting the call after the parentheses. That is going to get you an IEnumerable<System.Data.Linq.Binary[]> and then you call ToArray on that IEnumerable. I'm assuming there can only be one image with that key. Then it looks like you want var img = (from i in db.images where i.id == key select i.data).First().ToArray(); You probably want a null check after First().

[Jens Kloster]

+1, it worked for others to

[Cᴏʀʏ]

This answer is not useful -- the question asks about converting a System.Data.Linq.Bin‌​ary to a byte[] but this example converts a file path to a byte[] representation, with a Bitmap in between.

[Bertie]

The answer doesn't relate to the OP's question. The answer contains no reference to Linq.Binary type, which is 50% of what the OP is looking for. Please read the question properly before posting an answer.

[Balagurunathan Marimuthu]

Not just posting an answer, you could add little explanation which understand the solution better to OP and future readers as well.

[janv8000]

Works perfectly, no further explanation needed IMHO

[Fred]

The type cast is redundant.