2014/10/15 下午 10:13:19

iphone Programming Glossary: representation

http://stackoverflow.com/questions/10049533/correcting-floating-point-numbers

this problem in the first place see this wikipedia article IEEE 754 1985 . Basically floats are stored as a binary representation of the value and only have so many bits to use so they quickly run out and have to round to the nearest value that they..

HTML character decoding in Objective-C / Cocoa Touch

http://stackoverflow.com/questions/1105169/html-character-decoding-in-objective-c-cocoa-touch

References . When they take the form of # number they are called numeric entity references . Basically it's a string representation of the byte that should be substituted. In the case of #038 it represents the character with the value of 38 in the ISO..

How to get the RGB values for a pixel on an image on the iphone

http://stackoverflow.com/questions/144250/how-to-get-the-rgb-values-for-a-pixel-on-an-image-on-the-iphone

and match its color. Getting the UIImage is the easy part but is there a way to convert the UIImage data into a bitmap representation in which I could extract this information for a given pixel A working code sample would be most appreciated and note that.. function returns pre calculated RGBA divide RGB by A to get unmodified RGB RGBAPixel bitmap NSLog @ Returning bitmap representation of UIImage. 8 bits each of red green blue and alpha. self setBytesPerRow self.size.width RGBA self setByteCount bytesPerRow..

How to add a UIImage in MailComposer Sheet of MFMailComposeViewController

http://stackoverflow.com/questions/1527351/how-to-add-a-uiimage-in-mailcomposer-sheet-of-mfmailcomposeviewcontroller

the image into data NSData imageData NSData dataWithData UIImagePNGRepresentation emailImage Create a base64 string representation of the data using NSData Base64 NSString base64String imageData base64EncodedString Add the encoded string to the emailBody..

Cropping a UIImage

http://stackoverflow.com/questions/158914/cropping-a-uiimage

an image so I can get a scaled chunk of the center of the image I use this to take a UIImage and return a small square representation of an image similar to what's seen in the album view of the Photos app. I know I could use a UIImageView and adjust the..

Strange problem comparing floats in objective-C

http://stackoverflow.com/questions/1614533/strange-problem-comparing-floats-in-objective-c

comparing. Floating point numbers without a modifier are considered to be double in C. However in C there is no exact representation of 0.1 in floats and doubles. Now using a float gives you a small error. Using a double gives you an even smaller error...

Is there any way at all that I can tell how hard the screen is being pressed

http://stackoverflow.com/questions/2103447/is-there-any-way-at-all-that-i-can-tell-how-hard-the-screen-is-being-pressed

methods. However you can detect the size of touch with undocumented methods. In the GSEvent which is a lower level representation of UIEvent there is a structure known as GSPathInfo with members typedef struct GSPathInfo unsigned char pathIndex 0x0 0x5C..

iPhone - What are reuseIdentifiers (UITableViewCell)?

http://stackoverflow.com/questions/2152180/iphone-what-are-reuseidentifiers-uitableviewcell

is handled automatically . If scrolling to an area in the list where there are cells that haven't got their visual representation yet instead of instantiating new ones you reuse already existing ones. You can try this yourself by doing this static NSString..

Generate vCard from AddressBook.framework

http://stackoverflow.com/questions/2795615/generate-vcard-from-addressbook-framework

3.0 really help. UPDATE 3 If you're using iOS 5 or later there's now a function in ABPerson that can return the vCard representation of the given person records CFDataRef ABPersonCreateVCardRepresentationWithPeople CFArrayRef people UPDATE 2 I'm rushing.. solution you don't need to create any files even if they were only temporary. Plus you don't really need an NSString representation of the data anyway unless you did want to create a file and use it more than once to save re making the data My controller..

Save UIView's representation to file

http://stackoverflow.com/questions/3051630/save-uiviews-representation-to-file

UIView's representation to file What is the easiest way to save UIView's representation to file My solution is UIGraphicsBeginImageContext someView.frame.size.. UIView's representation to file What is the easiest way to save UIView's representation to file My solution is UIGraphicsBeginImageContext someView.frame.size someView drawRect someView.frame UIImage image UIGraphicsGetImageFromCurrentImageContext..

How to convert an NSString to hex values

http://stackoverflow.com/questions/3056757/how-to-convert-an-nsstring-to-hex-values

them into my code. Here are the Java methods I'm trying to reproduce Encodes the given string by using the hexadecimal representation of its UTF 8 bytes. @param s The string to encode. @return The encoded string. public static String utf8HexEncode String.. new RuntimeException x return String.valueOf Hex.encodeHex utf8 Decodes the given string by using the hexadecimal representation of its UTF 8 bytes. @param s The string to decode. @return The decoded string. @throws Exception If an error occurs. public.. would be utf8 s UTF8String NSString initWithUTF8String decodedHexString To make an NSString with the hexadecimal representation of a character string NSMutableString hex NSMutableString string while utf8 hex appendFormat @ 02X utf8 0x00FF You will..

Difference between [UIImage imageNamed…] and [UIImage imageWithData…]?

http://stackoverflow.com/questions/316236/difference-between-uiimage-imagenamed-and-uiimage-imagewithdata

example if you load an image 10 times to display along with some text in a table view UIImage will only keep a single representation of that image in memory instead of allocating 10 separate objects. On the other hand if you have a very large image and..

Convert decimal to fraction in Objective-C?

http://stackoverflow.com/questions/5552537/convert-decimal-to-fraction-in-objective-c

realNumber double ai AF division by zero break realNumber 1 realNumber double ai if realNumber double 0x7FFFFFFF AF representation failure break ai maxDenominator m 1 1 m 1 0 m 0 0 m 0 0 ai m 0 1 m 1 0 m 1 0 ai m 1 1 return Fraction .nominator m 0 0..

Moving a Stick figure, anchorpoints, animation, or something else…?

http://stackoverflow.com/questions/7808981/moving-a-stick-figure-anchorpoints-animation-or-something-else

modify the anchorPoint arbitrarily for every node in the game you no longer have any correlation between the visual representation of a node and its position. Thus it is bad design to modify the anchorPoint for gameplay objects. Furthermore rotation or..