I create an NSString using,
NSString *myString = [[NSString alloc] initWithBytes:someBuffer length:sizeof(someBuffer) encoding:NSASCIIStringEncoding];
I used NSLog to output myString and it displays "Hello".
If this is the case, then why does this fail.
NSString *helloString = #"Hello"
BOOL check = [myString isEqualToString:helloString];
Your myString variable is actually an NSString with a length of 64; the additional characters are probably undefined. What you most likely want to do is this:
NSString *myString = [[NSString alloc] initWithBytes:someBuffer length:strlen(someBuffer) encoding:NSASCIIStringEncoding];
This assumes a null-terminated C-string exists in your buffer.
There are probably some trailing characters that you can't see when calling NSLog(). For example: whitespace, linefeeds or even '\0' characters.
Check [myString length] to see if it returns 5.
Related
I have a code that creates an NSString and separates value with a comma. What I need to do is take that string, convert it to a NSArray and separate each value from the NSString between the commas, then iterate through each one. The code below returns the array as a single string
NSString *emails = #"testemail#gmail.com, testemail2#gmail.com";
NSArray *listItems = [emails componentsSeparatedByString:#", "];
for (int i = 0; i < [listItems count]; i++) {
NSString *address = (NSString*) [listItems objectAtIndex:i];
NSLog (#"ADDRESS: %#", address);
The Log shows the response testemail#gmail.com, testemail2#gmail.com when I want it to separate each one individually. Should this be an NSMutableArray instead?
The code is correct. You'll get two (separate) lines starting with ADDRESS:
But nowadays (actually since 2009!) it's highly recommended to use Fast Enumeration if the loop index is not needed
NSString *emails = #"testemail#gmail.com, testemail2#gmail.com";
NSArray *listItems = [emails componentsSeparatedByString:#", "];
for (NSString *email in listItems) {
NSLog(#"ADDRESS: %#", email);
}
I am using this to get the log files data:
NSFileHandle *file;
file = [NSFileHandle fileHandleForReadingAtPath:#"~/Library/Application Support/RepoManager/*.log"];
NSData *filedata;
filedata = [file readDataToEndOfFile];
NSString *logC;
logC = [[NSString alloc] initWithData:filedata encoding:NSASCIIStringEncoding];
And than write them using this:
NSString *formatString = #"Log: %#";
return [NSString stringWithFormat:formatString, *logC.stringValue];
But it says logC does not contain a string value
NSString does not define a .stringValue property, and even if it did, *logC.stringValue would have no useful meaning in Objective-C. logC itself is what you want to be using as your format parameter. (It's the string containing the contents of the log file.)
-[NSMutableAttributedString initWithHTML:documentAttributes:] seems to mangle special characters:
NSString *html = #"“Hello” World"; // notice the smart quotes
NSData *htmlData = [html dataUsingEncoding:NSUTF8StringEncoding];
NSMutableAttributedString *as = [[NSMutableAttributedString alloc] initWithHTML:htmlData documentAttributes:nil];
NSLog(#"%#", as);
That prints “Hello†World followed by some RTF commands. In my application, I convert the attributed string to RTF and display it in an NSTextView, but the characters are corrupted there, too.
According to the documentation, the default encoding is UTF-8, but I tried being explicit and the result is the same:
NSDictionary *attributes = #{NSCharacterEncodingDocumentAttribute: [NSNumber numberWithInt:NSUTF8StringEncoding]};
NSMutableAttributedString *as = [[NSMutableAttributedString alloc] initWithHTML:htmlData documentAttributes:&attributes];
Use [html dataUsingEncoding:NSUnicodeStringEncoding] when creating the NSData and set the matching encoding option when you parse the HTML into an attributed string:
The documentation for NSCharacterEncodingDocumentAttribute is slightly confusing:
NSNumber, containing an int specifying the NSStringEncoding for the
file; for reading and writing plain text files and writing HTML;
default for plain text is the default encoding; default for HTML is
UTF-8.
So, you code should be:
NSString *html = #"“Hello” World";
NSData *htmlData = [html dataUsingEncoding:NSUTF8StringEncoding];
NSDictionary *options = #{NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType,
NSCharacterEncodingDocumentAttribute: #(NSUTF8StringEncoding)};
NSMutableAttributedString *as =
[[NSMutableAttributedString alloc] initWithHTML:htmlData
options: options
documentAttributes:nil];
The previous answer here works, but mostly by accident.
Making an NSData with NSUnicodeStringEncoding will tend to work, because that constant is an alias for NSUTF16StringEncoding, and UTF-16 is pretty easy for the system to identify. Easier than UTF-8, which apparently was being identified as some other superset of ASCII (it looks like NSWindowsCP1252StringEncoding in your case, probably because it's one of the few ASCII-based encodings with mappings for 0x8_ and 0x9_).
That answer is mistaken in quoting the documentation for NSCharacterEncodingDocumentAttribute, because "attributes" are what you get out of -initWithHTML. That's why it's NSDictionary ** and not just NSDictionary *. You can pass in a pointer to an NSDictionary *, and you'll get out keys like TopMargin/BottomMargin/LeftMargin/RightMargin, PaperSize, DocumentType, UTI, etc. Any values you try to pass in through the "attributes" dictionary are ignored.
You need to use "options" for passing values in, and the relevant option key is NSTextEncodingNameDocumentOption, which has no documented default value. It's passing the bytes to WebKit for parsing, so if you don't specify an encoding, presumably you're getting WebKit's encoding-guessing heuristics.
To guarantee the encoding types match between your NSData and NSAttributedString, what you should do is something like:
NSString *html = #"“Hello” World";
NSData *htmlData = [html dataUsingEncoding:NSUTF8StringEncoding];
NSMutableAttributedString *as =
[[NSMutableAttributedString alloc] initWithHTML:htmlData
options:#{NSTextEncodingNameDocumentOption: #"UTF-8"}
documentAttributes:nil];
Swift version of accepted answer is:
let htmlString: String = "Hello world contains html</br>"
let data: Data = Data(htmlString.utf8)
let options: [NSAttributedString.DocumentReadingOptionKey: Any] = [
.documentType: NSAttributedString.DocumentType.html,
.characterEncoding: String.Encoding.utf8.rawValue
]
let attributedString = try? NSAttributedString(data: data,
options: options,
documentAttributes: nil)
I get a NSStrings with characters like \u00f6. I can't find how to encode it to UTF8.
NSString *resultString = [NSString stringWithContentsOfURL:wikiSearchURL usedEncoding:NSUTF8StringEncoding error:&err];
Thanks...
I think you want to do this:
NSString *resultString = [NSString stringWithContentsOfURL:wikiSearchURL encoding:NSUTF8StringEncoding error:&err];
the usedEncoding: one will tell you what encoding it used when it parsed the URL, while the encoding: one will force it to use a particular encoding.
NSString conceptually uses UTF-16 as its inernal format. 0x00F6 is a perfectly valid character to find in an NSString. It's o-umlaut. If you want to convert the string to UTF-8, use -UTF8String
const char* foo = [myString UTF8String];
Note that your line of code which gets a string from a URL and tries to figure out which encoding was used is wrong. You should use something like:
NSStringEncoding theEncoding;
NSString *resultString = [NSString stringWithContentsOfURL: wikiSearchURL usedEncoding: &theEncoding error:&err];
Assuming the returned string is not nil, theEncoding will now contain the encoding that was used to convert the URL content to the string.
I've Declared a string Like so
NSString* fileName = [files objectAtIndex:i];
NSLog(fileName);
NSImage* imageFromBundle = [[NSImage alloc] initWithContentsOfFile:fileName];
and want to use that filename to open a file in a different directory.
I came up with this
NSImage* imageFromBundle2;
imageFromBundle2 = [[NSImage alloc] initWithContentsOfFile:#"/Users/rhaynes/Documents/works4/" filename ];
Any help would be appreciated
I'll assume that your fileName string is actually a file name, like "myImage.png". A lot of the Objective-C docs refer to a file name when they really mean file path - so sometimes it's confusing.
What you want to do is create an NSString that represents the complete path to the file you want to load. For instance, you could say:
NSString * path = [NSString stringWithFormat: #"/Users/rhaynes/Documents/works4/%#", fileName];
That line creates a new NSString using the format string and parameters provided (the %# in the format string indicates that the string value of fileName should be inserted there.) StringWithFormat is a really powerful function, so you should definitely check it out in the docs.
Then you could call initWithContentsOfFile:path, and it should give you the image you want.
NSString* fileName = [files objectAtIndex:i]; NSLog(fileName);
Don't pass non-hard-coded strings as format-string arguments. If they contain format specifiers, you'll get garbage or a crash. (Try this with fileName = #"foo%sbar", for example. Then try it with fileName = #"foo%fbar" for even more fun.)
Your NSLog statement should be:
NSLog(#"%#", fileName);
[I] want to use that filename to open a file in a different directory. I came up with this
NSImage* imageFromBundle2; imageFromBundle2 = [[NSImage alloc] initWithContentsOfFile:#"/Users/rhaynes/Documents/works4/" filename ];
You can only concatenate string literals this way; as you've no doubt seen for yourself, this is a syntax error when one of the strings isn't a literal.
First off, if fileName is actually a pathname, you'll need to use lastPathComponent to get the actual filename. So:
NSString *path = [files objectAtIndex:i];
NSString *filename = [path lastPathComponent];
Then, use stringByAppendingPathComponent: to tack this onto the new superpath.
NSString *desiredFilenamePath = [directoryPath stringByAppendingPathComponent:filename];
Now you have the pathname you wanted to pass to NSImage's initializer.