How to decompress a varbinary file in database to a ZIP file? - asp.net-mvc

Question

In my application, I have to upload a ZIP file and then I have to make it available so that we can download that file again. As I am new to MVC, I have used a varbinary to store the data in the database.
Here is my view code:
#using (Html.BeginForm("Upload", "Createnews", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
#Html.AntiForgeryToken()
<div class="form-horizontal">
<h4>Createnew</h4>
<hr />
#Html.ValidationSummary(true, "", new { #class = "text-danger" })
<div class="form-group">
#Html.LabelFor(model => model.CategoryId, htmlAttributes: new { #class = "control-label col-md-2" })
<div class="col-md-10">
#Html.EditorFor(model => model.CategoryId, new { htmlAttributes = new { #class = "form-control" } })
#Html.ValidationMessageFor(model => model.CategoryId, "", new { #class = "text-danger" })
</div>
</div>
<div class="form-group">
#*#using (Html.BeginForm("Upload", "Createnews", FormMethod.Post, new { enctype = "multipart/form-data" }))
{*#
<table>
<tr>
<td>File:</td>
<td>
<input type="file" name="UploadedFile" />
</td>
</tr>
<tr>
<td colspan="2">
#*<input type="submit" name="Upload" value="Submit" />*#
</td>
</tr>
</table>
#*}*#
#Html.LabelFor(model => model.Complete_ZIP_file, htmlAttributes: new { #class = "control-label col-md-2" })
<div class="col-md-10">
#Html.EditorFor(model => model.Complete_ZIP_file, new { htmlAttributes = new { #class = "form-control" } })
#Html.ValidationMessageFor(model => model.Complete_ZIP_file, "", new { #class = "text-danger" })
</div>
</div>
<div class="form-group">
#Html.LabelFor(model => model.CategoryName, htmlAttributes: new { #class = "control-label col-md-2" })
<div class="col-md-10">
#Html.EditorFor(model => model.CategoryName, new { htmlAttributes = new { #class = "form-control" } })
#Html.ValidationMessageFor(model => model.CategoryName, "", new { #class = "text-danger" })
</div>
</div>
<div class="form-group">
#Html.LabelFor(model => model.SubCategoryId, htmlAttributes: new { #class = "control-label col-md-2" })
<div class="col-md-10">
#Html.EditorFor(model => model.SubCategoryId, new { htmlAttributes = new { #class = "form-control" } })
#Html.ValidationMessageFor(model => model.SubCategoryId, "", new { #class = "text-danger" })
</div>
</div>
<div class="form-group">
#Html.LabelFor(model => model.SubCategoryName, htmlAttributes: new { #class = "control-label col-md-2" })
<div class="col-md-10">
#Html.EditorFor(model => model.SubCategoryName, new { htmlAttributes = new { #class = "form-control" } })
#Html.ValidationMessageFor(model => model.SubCategoryName, "", new { #class = "text-danger" })
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
#*<input type="submit" value="Create" class="btn btn-default" />*#<input type="submit" name="Upload" value="Submit" />
</div>
</div>
</div>
}
Then I have written the following code in the controller:
public ActionResult Upload([Bind(Include = "CategoryId,Complete_ZIP_file,CategoryName,SubCategoryId,SubCategoryName")] Createnew createnew)
{
if (Request != null)
{
HttpPostedFileBase file = Request.Files["UploadedFile"];
if ((file != null) && (file.ContentLength > 0) && !string.IsNullOrEmpty(file.FileName))
{
string fileName = file.FileName;
string fileContentType = file.ContentType;
byte[] fileBytes = new byte[file.ContentLength];
file.InputStream.Read(fileBytes, 0, Convert.ToInt32(file.ContentLength));
createnew.Complete_ZIP_file = fileBytes;
}}
if (ModelState.IsValid)
{
db.Createnews.Add(createnew);
db.SaveChanges();
return RedirectToAction("Index");
}
//return View(createnew)
return View("Create");
}
Now, I the result is getting stored in the appropriate field. Now, I will have to make it available as a download. So, how can I convert this varbinary format to a ZIP file again?
Thanks in advance.

Answer 1

you dont need convert to varbinary to zip. you can directly write to response.
public ActionResult Download()
{
//read varbinary field from db
byte[] output = GetOutputFromDb();
return File(output, "application/zip", "fileName.zip");
}