Use MemoryStream and ZipArchive to return zip file to client in asp.net web api
$.ajax
handles text responses and will try to (utf-8) decode the content: your zip file isn't text, you will get a corrupted content. jQuery doesn't support binary content so you need to use this link and add an ajax transport on jQuery or use directly a XmlHttpRequest. With an xhr, you need to set xhr.responseType = "blob"
and read from xhr.response
the blob.
// with xhr.responseType = "arraybuffer"
var arraybuffer = xhr.response;
var blob = new Blob([arraybuffer], {type:"application/zip"});
saveAs(blob, "example.zip");
// with xhr.responseType = "blob"
var blob = xhr.response;
saveAs(blob, "example.zip");
Edit: examples:
with jquery.binarytransport.js (any library that let you download a Blob or an ArrayBuffer will do)
$.ajax({
url: url,
type: "POST",
contentType: "application/json",
dataType: "binary", // to use the binary transport
// responseType:'blob', this is the default
data: data,
processData: false,
success: function (blob) {
// the result is a blob, we can trigger the download directly
saveAs(blob, "example.zip");
}
// [...]
});
with a raw XMLHttpRequest, you can see this question, you just need to add a xhr.responseType = "blob"
to get a blob.
I personally recommended you to use an ajax transport on jQuery, that's very easy, you have to download a library, include it in the project and write: dataType: "binary".
This is the API code, using DotNetZip (Ionic.Zip
):
[HttpPost]
public HttpResponseMessage ZipDocs([FromBody] string[] docs)
{
using (ZipFile zip = new ZipFile())
{
//this code takes an array of documents' paths and Zip them
zip.AddFiles(docs, false, "");
return ZipContentResult(zip);
}
}
protected HttpResponseMessage ZipContentResult(ZipFile zipFile)
{
var pushStreamContent = new PushStreamContent((stream, content, context) =>
{
zipFile.Save(stream);
stream.Close();
}, "application/zip");
return new HttpResponseMessage(HttpStatusCode.OK) { Content = pushStreamContent };
}
This is suitable for asp.net core version.
[HttpGet("api/DownloadZip")]
public async Task<IActionResult> Download()
{
var path = "C:\\test.zip";
var memory = new MemoryStream();
using (var stream = new FileStream(path, FileMode.Open))
{
await stream.CopyToAsync(memory);
}
memory.Position = 0;
return File(memory, GetContentType(path), Path.GetFileName(path));
}
Then use Web client call
class Program
{
static string url = "http://localhost:5000/api/DownloadZip";
static async Task Main(string[] args)
{
var p = @"c:\temp1\test.zip";
WebClient webClient = new WebClient();
webClient.DownloadFile(new Uri(url), p);
Console.WriteLine("ENTER to exit...");
Console.ReadLine();
}
}
Here is my solution that worked for me
C# side
public IActionResult GetZip([FromBody] List<DocumentAndSourceDto> documents)
{
List<Document> listOfDocuments = new List<Document>();
foreach (DocumentAndSourceDto doc in documents)
listOfDocuments.Add(_documentService.GetDocumentWithServerPath(doc.Id));
using (var ms = new MemoryStream())
{
using (var zipArchive = new ZipArchive(ms, ZipArchiveMode.Create, true))
{
foreach (var attachment in listOfDocuments)
{
var entry = zipArchive.CreateEntry(attachment.FileName);
using (var fileStream = new FileStream(attachment.FilePath, FileMode.Open))
using (var entryStream = entry.Open())
{
fileStream.CopyTo(entryStream);
}
}
}
ms.Position = 0;
return File(ms.ToArray(), "application/zip");
}
throw new ErrorException("Can't zip files");
}
don't miss the ms.Position = 0;
here
Front side (Angular 4) :
downloadZip(datas: any) {
const headers = new Headers({
'Content-Type': 'application/json',
'Accept': 'application/zip'
});
const options = new RequestOptions({ headers: headers, withCredentials: true, responseType: ResponseContentType.ArrayBuffer });
const body = JSON.stringify(datas);
return this.authHttp.post(`${environment.apiBaseUrl}api/documents/zip`, body, options)
.map((response: Response) => {
const blob = new Blob([response.blob()], { type: 'application/zip' });
FileSaver.saveAs(blob, 'logs.zip');
})
.catch(this.handleError);
}
Now I'm able to download multiple files to zip.