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c#asp.netlinqbinaryfiles
Ron
Ron

Reputation: 1931

opening binary files from SQL using LINQ

I am saving my word/excel/pdf/Img files in SQL using binary and i am able to successfully save the files as binary.

var fileSize = FileUpload1.PostedFile.ContentLength;
var documentBinary = new byte[fileSize];
var u = new UDocument
                {
                    DocName = fileName.ToString(CultureInfo.InvariantCulture),
                    Type = documentType.ToString(CultureInfo.InvariantCulture),
                    DocData = documentBinary
                };
                u.DocID = ++count;
                sd.UDocuments.InsertOnSubmit(u);
                sd.SubmitChanges();

Now, i am trying to open the binary as their document type, and i am opening this from the gridview where i am displaying all the stored files.

enter image description here

Now, in Gridview SelectedIndexChange Event, i am able to get the document ID, document name, for me to open the file,but i am unclear about how to grab the binary data from the documentID, which is the PK, and how to write the file out. Here is the method i am trying to make it to work:

protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
    {
        int docid = Convert.ToInt16(GridView1.SelectedRow.Cells[1].Text);
        string name = GridView1.SelectedRow.Cells[2].Text;
        Response.Clear();
        Response.ContentType = "application/octet-stream";
        Response.AddHeader("Content-Disposition", "attachment;filename=" + name);
        Response.BinaryWrite(GetData(docid)); // I am unclear on how to use this method, with the 
        Response.Flush();
    }

where, in my GetData(int id) method, i am trying to use LINQ to get the correct binary data through the unique docID like this: 

var data = from a in sd.UDocuments
            where a.DocID == id
            select a.DocData

but i am not sure what return type to use in this method.

Any help or pointers will be great.

Upvotes: 0

Views: 1346

Answers (2)

Ron
Ron

Reputation: 1931

 private byte[] GetData(int id)
    {
        byte[] data = (from a in sd.UDocuments
            where a.DocID == id
            select a.DocData).First().ToArray();
       return data;
    }

protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
    {
        int docid = Convert.ToInt16(GridView1.SelectedRow.Cells[1].Text);
        string name = GridView1.SelectedRow.Cells[2].Text;
        string contentType = GridView1.SelectedRow.Cells[3].Text;

        Response.Clear();
        Response.ContentType = contentType; //"application/octet-stream";
        Response.AddHeader("Content-Disposition", "attachment;filename=" + name);
        Response.BinaryWrite(GetData(docid));
        Response.End();
    }

Upvotes: 0

Tomas Grosup
Tomas Grosup

Reputation: 6514

The return type of GetData should be the same as the type of your DocData property, i.e. byte[].

Upvotes: 1

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