System.Text.Encoding in WinJS

Question

Is there an equivalent of

System.Text.Encoding.UTF8.GetString(fileContent)

in WinJS (Windows 8 Store App written in javascript/HTML)?

EDIT. fileContent is a byte array.

What is fileContent, stream? array? what you're trying to accomplish? — T W, Aug 13 '13 at 13:40
fileContent is a byte array. I am trying to convert it to a string. — Jarek Mazur, Aug 13 '13 at 13:42
I am trying to read file as in this question: http://stackoverflow.com/questions/18206590/winrt-no-mapping-for-the-unicode-character-exists-in-the-target-multi-byte-code but in WinJS — Jarek Mazur, Aug 13 '13 at 13:44

score 2 · Accepted Answer · edited Jul 12 '16 at 21:46

2

There is no strict equivalent of System.Text.Encoding.UTF8.GetString in WinJS, but you can try implement file reading to string as follows:

file.openReadAsync().done(function (stream) {
   var blob = MSApp.createBlobFromRandomAccessStream(file.contentType, stream);
   var reader = new FileReader();

   reader.onload = function(event) {
      var fileAsText = event.target.result;
   };

   reader.readAsText(blob, 'UTF-8');
});

In most cases (file upload via XHR, displaying file) you don't need to have file contents as text, so just use Blob then.

edited Jul 12 '16 at 21:46

roryok

9,325
17
71
138

answered Aug 13 '13 at 14:15

T W

6,267
2
26
33

Ok works great, but you have one small error in your code: you forgot to add parenthesis after openReadAsync (it should be file.openReadAsync().done(...)) – Jarek Mazur Aug 14 '13 at 08:10
One more question - do you happen to know how to handle unicode symbols (file I am trying to read contains polish letters) – Jarek Mazur Aug 14 '13 at 08:11
thanks, that was the only way i could read a text file from Excel with dutch characters (saved as encoding LATIN1) – fnicollet Apr 12 '16 at 10:19

Sushil · Answer 2 · 2013-08-14T08:59:59.257

0

CryptographicBuffer.convertBinaryToString can be used for this.

var crypt = Windows.Security.Cryptography;
var bytes; // = new Uint8Array(100);
// TODO - set bytes variable with uint8array
var buffer = crypt.CryptographicBuffer.createFromByteArray(bytes);
var text = crypt.CryptographicBuffer.convertBinaryToString(
    crypt.BinaryStringEncoding.utf8, buffer);

edited Aug 14 '13 at 08:59

answered Aug 14 '13 at 04:44

Sushil

5,265
2
17
15

Using your approach I get runtime exception: "No mapping for the Unicode character exists in the target multi-byte code page." – Jarek Mazur Aug 14 '13 at 08:17

System.Text.Encoding in WinJS

2 Answers2