Forgive me if this question is already answered somewhere on this site, but I didn't find anything when I searched for it. I've written a ID3v1/2 tag editor for .mp3 files in C# using taglib-sharp, and taglib-sharp treats the track numbers as uint numbers. According to id3.org:
The 'Track number/Position in set' frame is a numeric string
containing the order number of the audio-file on its original
recording. This may be extended with a "/" character and a numeric
string containing the total numer of tracks/elements on the original
recording. E.g. "4/9".
Personally I don't use "/", but I tend to write "03" instead of "3". Is there a simple way to write the track number to the tag as a string directly, instead of via a uint?
Also, side question: taglib doesn't seem to support some tags, specifically URL, Orig. Artist, Publisher and Encoded. Any idea on what to do with those?
UPDATE: Since this answer was originally written, GetTextAsString was made public. This answer has been updated to reflect that.
The Track field in TagLib# is a universal approximation and simplification of various tagging specifications intent for the tag field. For ID3v2 tags, this is assuming the TRCK field consists of one or two numbers strings separated by a slash and converting them into numbers, per the specification.
That said, it is a text field and you can do whatever you want with it. You just need to access the text frame to read or write it.
Writing is easy through Id3v2.Tag.SetTextFrame:
var tag = (Id3v2.Tag)file.GetTag(TagTypes.Id3v2, true); // Get or create ID3v2 tag.
tag.SetTextFrame("TRCK", "03"); // Add or update TRCK frame.
Since TRCK is a single-string text frame, it can similarly be read using Id3v2.Tag.GetTextAsString:
var tag = (Id3v2.Tag)file.GetTag(TagTypes.Id3v2, false);
var trackNumber = tag?.GetTextAsString("TRCK");
No you can't save a string into an int or uint without casting it first. Why don't just you save your value 3 as a uint as per the library you are using and use something like:
uint track = 3;
string strTrack = track.ToString("00");
to display it?
If it's allowed by its license, you can still modify the library to suit your needs.
I've taken a quick look at taglib sharp in the past and it's far from supporting all existing frames in a tag. It supports the most common frames only. For the other ones, I think there is some kind of default class you can use but I don't recall the name. Otherwise you can still go and extend the library by yourself unless there are some other such libraries available, which I am not aware of.
Related
Ok the title may be not correct but this is what i came as best
My question is this
Example 1
see , saw
I can convert see to saw with as
replace ee with aw
string srA = "see";
string srB = "saw";
srA = srB.Replace("aw", "ee");
Or lets say
show , shown
add n to original string
Now what i want it is, with minimum length of code, generating such procedures to any compared strings
Looking for your ideas how can i make it? Can i generate regexes automatically to apply and convert?
c# 6
Check diffplex and and see if it is what you need. If you want to create a custom algorithm, instead of using a 3rd party library just go through the code -it's open source.
You might also want to check this work for optimizations, but it might get complicated.
Then there's also Diff.NET.
Also this blog post is part of a series in implementing a diff tool.
If you're simply interested in learning more about the subject, your googling efforts should be directed to the Levenshtein algorithm.
I can only assume what your end goal is, and the time you're willing to invest in this, but I believe the first library should be enough for most needs.
I am designing a text file format to be read in C#. I have a need to store types: int, double and string on a single line. I'm planning to use a .CSV format so the file can be manually opened and read. A particular record may have say 8 known types, then a variable number of "indicator" combinations of either (string, int, double) or (string, int, double, double), and some lines may include no "indicators". Thus, each record is may be of variable length.
In VB6 I would just input the data, split the data, into a variant array, then determine the number of elements on that line in the array, and use the ***VarType function to determine if the final "indicator" variables are string, int, or double and parse the field accordingly.
There may be a better way to design a text file and that may be the best solution. If so I'm interested in hearing ideas. I have searched but found no questions that specifically talk about reading variable length lines of text with mixed type into C#.
If a better format is not forthcoming, is there a way to duplicate the VB6 VarType function within C# as described two paragraphs above***? I can handle the text file reading and line splitting easily in C#.
you could use either json or xml as they are well supported in .NET and have automatic serialization capabilities
First I agree with Keith's suggestion to use Xml or JSON. You are reinventing a wheel here. This page has an introductory example of how to serialize objects to a file and some links to more info.
If you need to stick with your own file format and custom serialization/deserialization however take a look at the Convert class, as well as the various TryParse methods which hang off of the intrinsic value types like int and double.
I have a text file that has the following format:
1234
ABC123 1000 2000
The first integer value is a weight and the next line has three values, a product code, weight and cost, and this line can be repeated any number of times. There is a space in between each value.
I have been able to read in the text file, store the first value on the first line into a variable, and then the subsequent lines into an array and then into a list, using first readline.split('').
To me this seems an inefficient way of doing it, and I have been trying to find a way where I can read from the second line where the product codes, weights and costs are listed down into a list without the need of using an array. My list control contains an object where I am only storing the weight and cost, not the product code.
Does anyone know how to read in a text file, take in some values from the file straight into a list control?
Thanks
What you do is correct. There is no generalized way of doing it, since what you did is that you descirbed the algorithm for it, that has to be coded or parametrized somehow.
Since your text file isn't as structured as a CSV file, this kind of manual parsing is probably your best bet.
C# doesn't have a Scanner class like Java, so what you wan't doesn't exist in the BCL, though you could write your own.
The other answers are correct - there's no generalized solution for this.
If you've got a relatively small file, you can use File.ReadAllLines(), which will at least get rid of a lot cruft code, since it'll immediately convert it to a string array for you.
If you don't want to parse strings from the file and to reserve an additional memory for holding split strings you can use a binary format to store your information in the file. Then you can use the class BinaryReader with methods like ReadInt32(), ReadDouble() and others. It is more efficient than read by characters.
But one thing: binary format is bad readable by humans. It will be difficult to edit the file in the editor. But programmatically - without any problems.
I am writing a program to diff, and copy entire files or segments based on changes on either end (Rsync-esque... but more like Unison). The main idea is to keep my music folder (all mp3s) up to date over multiple locations.
I'd like to send segmented updates if only small portions of the file have changed, as opposed to copying the entire file. For this, I need a way to diff segments of the file.
I initially tried generating hashes for blocks of every file (Every n bytes I'd hash the segment). I noticed that when I changed one attribute (id3v2 tag on an mp3) all the hashed blocks would change. This makes sense, as I would guess the header is growing as it acquired new information.
This leads me to my actual question. I would like to know how to determine the length of an mp3's header, so I could create 2 comparable hashes.
1) The meta info of the file (header)
2) The actual mpeg stream with audio (This hash should remain unchanged if all I do is alter tag info)
Am I missing anything else?
Thanks!
Ty
If all you want to check the length of is id3v2 tags, then you can find out information about its structure at http://www.id3.org/id3v2.4.0-structure.
If you read the first 3 bytes, and they are equal to "ID3", then skip to the 7th byte, then read the header size. Be careful though, because the size is stored as a "synchsafe integer".
If you want to determine the header information, you'll either:
a) need to use a mp3 library that can do the parsing for you, or
b) go to the mp3 specification and parse it out as needed.
I wound up using TagLibSharp. developer.novell.com/wiki/index.php/TagLib_Sharp
For the project that I'm currently on, I have to deliver specially formatted strings to a 3rd party service for processing. And so I'm building up the strings like so:
string someString = string.Format("{0}{1}{2}: Some message. Some percentage: {3}%", token1, token2, token3, number);
Rather then hardcode the string, I was thinking of moving it into the project resources:
string someString = string.Format(Properties.Resources.SomeString, token1, token2, token3, number);
The second option is in my opinion, not as readable as the first one i.e. the person reading the code would have to pull up the string resources to work out what the final result should look like.
How do I get around this? Is the hardcoded format string a necessary evil in this case?
I do think this is a necessary evil, one I've used frequently. Something smelly that I do, is:
// "{0}{1}{2}: Some message. Some percentage: {3}%"
string someString = string.Format(Properties.Resources.SomeString
,token1, token2, token3, number);
..at least until the code is stable enough that I might be embarrassed having that seen by others.
There are several reasons that you would want to do this, but the only great reason is if you are going to localize your application into another language.
If you are using resource strings there are a couple of things to keep in mind.
Include format strings whenever possible in the set of resource strings you want localized. This will allow the translator to reorder the position of the formatted items to make them fit better in the context of the translated text.
Avoid having strings in your format tokens that are in your language. It is better to use
these for numbers. For instance, the message:
"The value you specified must be between {0} and {1}"
is great if {0} and {1} are numbers like 5 and 10. If you are formatting in strings like "five" and "ten" this is going to make localization difficult.
You can get arround the readability problem you are talking about by simply naming your resources well.
string someString = string.Format(Properties.Resources.IntegerRangeError, minValue, maxValue );
Evaluate if you are generating user visible strings at the right abstraction level in your code. In general I tend to group all the user visible strings in the code closest to the user interface as possible. If some low level file I/O code needs to provide errors, it should be doing this with exceptions which you handle in you application and consistent error messages for. This will also consolidate all of your strings that require localization instead of having them peppered throughout your code.
One thing you can do to help add hard coded strings or even speed up adding strings to a resource file is to use CodeRush Xpress which you can download for free here: http://www.devexpress.com/Products/Visual_Studio_Add-in/CodeRushX/
Once you write your string you can access the CodeRush menu and extract to a resource file in a single step. Very nice.
Resharper has similar functionality.
I don't see why including the format string in the program is a bad thing. Unlike traditional undocumented magic numbers, it is quite obvious what it does at first glance. Of course, if you are using the format string in multiple places it should definitely be stored in an appropriate read-only variable to avoid redundancy.
I agree that keeping it in the resources is unnecessary indirection here. A possible exception would be if your program needs to be localized, and you are localizing through resource files.
yes you can
new lets see how
String.Format(Resource_en.PhoneNumberForEmployeeAlreadyExist,letterForm.EmployeeName[i])
this will gave me dynamic message every time
by the way I'm useing ResXManager