How does Encoding.Default work in .NET?

Question

I'm reading a file using:

var source = File.ReadAllText(path);

and the character © wasn't being loaded correctly.

Then, I changed it to:

var source = File.ReadAllText(path, Encoding.UTF8);

and nothing.

I decided to try using

var source = File.ReadAllText(path, Encoding.Default);

and it worked perfectly. Then I debugged it and tried to find which Encoding did the trick, and I found that it was UTF-7.

What I want to know is:

Is it recommended to use Encoding.Default, and can it guarantee all the characters of the file will be read without problems?

Answer 1

Encoding.Default will only guarantee that all UTF-7 character sets will be read correctly (google for the whole set). On the other hand, if you try to read a file not encoded with UTF-8 in the UTF-8 mode, you'll get corrupted characters like you did.

For instance if the file is encoded UTF-16 and if you read it in UTF-16 mode, you'll be fine even if the file does not contain a single UTF-16 specific character. It all boils down to the file's encoding.

You'll need to do the save - reopen stuff with the same encoding to be safe from corruptions. Otherwise, try to use UTF-7 as much as you can since it is the most compact yet 'email safe' encoding possible, which is why it is default in most .NET framework setups.

Answer 2

It sounds like you are interested in auto-detecting the encoding of a file, in some sort of situation where you are not in control of the encoding used to save it. There are several questions on StackOverflow addressing this; some cursory browsing points to Determine a string's encoding in C# as a pretty good one. My favorite answer is the one pointing to a C# port of Mozilla's universal charset detector.

Answer 3

I think the ur file is in utf-7 encoding.nothing more. visit this page Your Answer

Answer 4

It is not recommended to use Encoding.Default.

Quote from MSDN:

Different computers can use different encodings as the default, and the default encoding can even change on a single computer. Therefore, data streamed from one computer to another or even retrieved at different times on the same computer might be translated incorrectly. In addition, the encoding returned by the Default property uses best-fit fallback to map unsupported characters to characters supported by the code page. For these two reasons, using the default encoding is generally not recommended. To ensure that encoded bytes are decoded properly, your application should use a Unicode encoding, such as UTF8Encoding or UnicodeEncoding, with a preamble. Another option is to use a higher-level protocol to ensure that the same format is used for encoding and decoding.