nsstring

Why dereferencing a NSString pointer is not necessary?

由 做~自己de王妃 提交于 2019-11-27 01:59:33
问题 In the example NSString *message = @"Hello"; message = @"World"; If message is just a pointer why don't I need to explicitly say whatever is in message is now equal to string or *message = @"World"; like in C? 回答1: DISCLAIMER The discussion below gives a general idea on why you never dereferenciate a pointer to an object in Objective-C. However, concerning the specific case of NSString literals, this is not what's happening in reality. While the structure described below is still sound and it

ios drawRect NSString 绘制

由 隐身守侯 提交于 2019-11-27 01:56:17
- (void)drawRectFor7 { #if __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_7_0 UIFont *font = [UIFont boldSystemFontOfSize:_fontSize]; NSDictionary *attributes = nil; NSDictionary *strokeAttributes = nil; if (_useLightText) { strokeAttributes = [NSDictionary dictionaryWithObjectsAndKeys:font, NSFontAttributeName, _strokeColor, NSStrokeColorAttributeName, @-10.0, NSStrokeWidthAttributeName, nil]; attributes = [NSDictionary dictionaryWithObjectsAndKeys:font, NSFontAttributeName, _lightColor, NSForegroundColorAttributeName, nil]; } else { attributes = [NSDictionary dictionaryWithObjectsAndKeys:font,

How to convert NSString HTML markup to plain text NSString?

由 ￣綄美尐妖づ 提交于 2019-11-27 01:55:24
问题 Been searching the net for an example of how to convert HTML string markup into Plain text. I get my information from a feed which contains HTML , I then display this information in a Text View. does the UITextView have a property to convert HTML or do I have to do it in code. I tried: NSString *str = [NSString stringWithCString:self.fullText encoding:NSUTF8StringEndcoding]; but doesn't seem to work. Anyone got any ideas? 回答1: You can do it by parsing the html by using NSScanner class -

Compare two NSStrings

由 主宰稳场 提交于 2019-11-27 01:50:15
问题 In my app there is a mechanism that requires that at a certain point two NSString s will be the same to do something; for some reason when I compare the two, even when they are the same, it still doesn't recognize that. The code is something like this: NSString * aString = [self someMethodThatGetsAString]; NSString * bString; BOOL areStringsTheSame = NO; while (areStringsTheSame != YES) { bString = [self someMethodThatTakesNSStringsFromAnArrey]; if (bString == aString) { areStringsTheSame =

What is the maximum length of an NSString object?

由 喜你入骨 提交于 2019-11-27 01:48:42
What is the maximum sized string that can be held in a NSString object? Does this change dynamically? I would assume the hard limit for NSString would be NSUIntegerMax characters, since NSString's index and size-related methods return an NSUInteger. Since all devices currently capable of running iOS are 32 bit, this means NSUIntegerMax is 2^32 - 1 and NSString can hold a little over 4.2 billion characters. As others have pointed out, though, the practical limit is much smaller - on an iOS device especially, you'll run out of memory long before you hit any hard limit in NSString. NSString is

NSString initWithData returns null

由 风格不统一 提交于 2019-11-27 01:47:46
问题 I am pulling data from a website via NSURLConnection and stashing the received data away in an instance of NSMutableData . In the connectionDidFinishLoading delegate method the data is convert into a string with a call to NSString's appropriate method: NSString *result = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding] The resulting string turns out to be a null. If I use the NSASCIIStringEncoding , however, I do obtain the appropriate string, albeit with unicode characters

sizeWithFont doesn't give correct height for UITextView if there is a long string in the text being wrapped

由 浪尽此生 提交于 2019-11-27 01:43:00
问题 Is there a way to get the correct size of an NSString using: - (CGSize)sizeWithFont:(UIFont *)font forWidth:(CGFloat)width lineBreakMode:(UILineBreakMode)lineBreakMode that doesnt get thrown off by 2 or 3 hundred character strings. At the moment if I try to use this method on these long strings it incorrectly calculates them and I end up with lots of whitespace at the bottom of the UITextView. I've tried using UILineBreakModeWordWrap and UILineBreakModeCharacterWrap. the resizing is being

Can't convert NSData to NSString in swift

由 旧城冷巷雨未停 提交于 2019-11-27 01:41:12
问题 This is my function. First println print correct hash to console but in the next row program crashes. Can you help me? func sha256(string: NSString) -> NSString { var data : NSData! = string.dataUsingEncoding(NSUTF8StringEncoding) var hash = [UInt8](count: Int(CC_SHA256_DIGEST_LENGTH), repeatedValue: 0) CC_SHA256(data.bytes, CC_LONG(data.length), &hash) let res = NSData(bytes: hash, length: Int(CC_SHA256_DIGEST_LENGTH)) println(res) let resstr = NSString(data: res, encoding:

iOS - Most efficient way to find word occurrence count in a string

由 女生的网名这么多〃 提交于 2019-11-27 01:39:55
问题 Given a string, I need to obtain a count of each word that appears in that string. To do so, I extracted the string into an array, by word, and searched that way, but I have the feeling that searching the string directly is more optimal. Below is the code that I originally wrote to solve the problem. I'm up for suggestions on better solutions though. NSMutableDictionary *sets = [[NSMutableDictionary alloc] init]; NSString *paragraph = [[NSString alloc] initWithContentsOfFile:[[NSBundle

How to create subscript characters that's not in Unicode in iOS

由 拜拜、爱过 提交于 2019-11-27 01:37:53
I've been trying for a while now to create a NSString with subscripted character without success. Is it even possible to do this in iOS? I need a way to change characters in a string to subscript or superscript, and I can't use the Unicode for this as Unicode doesn't have all the letters. My guess could be to use the HTML tags <sub> and <sup> but I haven't find a way to convert said HTML tags to a NSString. Subscript and superscript are not character traits. With few exceptions (e. g. ², ³, ª), this is the way regular characters are rendered - in a smaller font and above/below the regular
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