Add byte[] to ZipFile as file.jpg with HttpResponse

Question

I've got this code snipped that download successfully:

byte[] bytes;
bytes = Convert.FromBase64String(lehrling.passfoto);
Response.Clear();
Response.Cache.SetCacheability(HttpCacheability.NoCache);
Response.ContentType = "image/jpg";
Response.AddHeader("content-disposition", "attachment; filename=" + lehrling.vorname + "." + lehrling.nachname + ".jpeg");
Response.OutputStream.Write(bytes, 0, bytes.Length);
Response.End()

This works just fine. I get a jpeg file out of it. Now:

I created a for-loop that executes the code shown above for each bytearray:

    for (int i = 0; i < anzahlBilder; i++)
    {
         //My Code here
    }
    Response.End()

I get anzahlBilder from somewhere else. its not important for my question. I put Response.End() outside of my for-loop because otherwise it ends after 1 image got downloaded.

To Zip:

Now i want to create a .Zip file, which contains all my images. I dont know how to do it. Any Suggestions?

[System.IO.Compression.ZipFile](https://msdn.microsoft.com/en-us/library/system.io.compression.zipfile(v=vs.110).aspx) ? — Marc Gravell, Oct 10 '16 at 11:57
yes, but what do i write as parameters in my example? could you provide a code sample ? — Alessandro Minneci, Oct 10 '16 at 12:02

Imad · Accepted Answer · 2016-10-10T14:06:42.907

0

By using System.IO.Compression.ZipFile

You need to add a dll reference to the assembly, "System.IO.Compression.FileSystem.dll" and import namespace.

System.IO.Compression

at the top.

    ZipFile zipFile = new ZipFile();
    for(int i = 0; i < anzahlBilder; i++)
    {
        using (MemoryStream ms= new MemoryStream(Convert.FromBase64String(lehrling.passfoto)))
        {
            Image userImage = Image.FromStream(ms);   
            userImage.Save(ms, ImageFormat.Jpeg);  
            ms.Seek(0, SeekOrigin.Begin);
            byte[] imageData = new byte[ms.Length];
            ms.Read(imageData, 0, imageData.Length);
            zipFile.AddEntry(lehrling.vorname + "." + lehrling.nachname + ".jpeg", imageData);
        }
    }

    zipFile.Save(Response.OutputStream);

make required changes in place of lehrling.passfoto and lehrling.vorname + "." + lehrling.nachname + ".jpeg" to get it work.

edited Oct 10 '16 at 14:06

answered Oct 10 '16 at 12:11

Imad

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Thanks for the answer, i can create a ZipFile instance thoe. It sais it must be convertible to System.IDisponsable, any idea why? – Alessandro Minneci Oct 10 '16 at 12:16
Which line?____ – Imad Oct 10 '16 at 12:19
what do i set as tempstream ? – Alessandro Minneci Oct 10 '16 at 12:19
not working either, it sais it cant be defined like that – Alessandro Minneci Oct 10 '16 at 12:23
What is exact message? – Imad Oct 10 '16 at 12:24
the type, used in a using statement must be convertible to idisponsable. the error when i try with updated code is: ZipFile cannot be defined – Alessandro Minneci Oct 10 '16 at 12:25
please paste exact error after using updated code. What you are mentioning is not dotnet error – Imad Oct 10 '16 at 12:27
What .net version you are using? – Imad Oct 10 '16 at 12:29
i am using .net 4.5.2 / the exact message is: cannot create an instance of the static class ZipFile – Alessandro Minneci Oct 10 '16 at 13:52
i know why i am getting this error...... can you change your answer from ZipFile - Class to ZipArchive - Class and adjust the code... so i can mark as answered – Alessandro Minneci Oct 10 '16 at 14:00
check updated answer, just import dll and use reference in code – Imad Oct 10 '16 at 14:01
If you are naming the file `.jpeg` why are you useing `ImageFormat.Png`? – Matthew Whited Oct 10 '16 at 14:05
@MatthewWhited nice catch – Imad Oct 10 '16 at 14:06
and if you just want the byte array from the `MemoryStream` just call `.ToArray()` – Matthew Whited Oct 10 '16 at 14:06
i've already done that. not the reference is the problem. i think its my .net version. can you provide code with the ZipArchive class. that one works, but i dont know how to adjust the code to get it to work @Imad – Alessandro Minneci Oct 10 '16 at 14:29
Its fine if your code is working, you can post it as your own answer :) – Imad Oct 10 '16 at 14:31
there is not even a .AddEntry for the ZipFile class @Imad – Alessandro Minneci Oct 11 '16 at 05:55

Add byte[] to ZipFile as file.jpg with HttpResponse

1 Answers1