2014/10/15 下午 10:13:19

iphone Programming Glossary: represent

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

the approved answer iphone ios xcode cocoa touch cocoa share improve this question Floating point numbers do not represent specific numbers very well. Using double's will make this happen less often but you will still have the problem. For a technical.. 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.. only have so many bits to use so they quickly run out and have to round to the nearest value that they are capable of representing. Typically you don't worry about the .0000001 and just format them when you want to display them to the user with the..

How to create a UIImage from the current graphics context?

http://stackoverflow.com/questions/1112947/how-to-create-a-uiimage-from-the-current-graphics-context

view that the user can draw lines on. They may draw incrementally. After they are done I'd like to create a UIImage to represent their drawing. Here is what drawRect looks like for me now void drawRect CGRect rect CGContextRef c UIGraphicsGetCurrentContext.. may be invoked several times as the user draws. When the user is done I'd like to create a UIImage object that represents the graphics context. Any suggestions on how to do this iphone uiimage core graphics quartz graphics share improve this..

MKMapView Zoom and Region

http://stackoverflow.com/questions/1166444/mkmapview-zoom-and-region

span's latitude and longitude delta values to specify zoom level. But I really don't have an idea what these values represent I read the documentation . When I use a MKMapView delegate and trace the span values in regionDidChange delegate method.. center point of the region. However span which is a MKCoordinateSpan consists of latitudeDelta the vertical distance represented by the region and longitudeDelta the horizontal distance represented by the region . A brief example. Here's a toy MKCoordinateRegion.. consists of latitudeDelta the vertical distance represented by the region and longitudeDelta the horizontal distance represented by the region . A brief example. Here's a toy MKCoordinateRegion center latitude 0 longitude 0 span latitudeDelta 8 longitudeDelta..

Add UIPickerView & a Button in Action sheet - How?

http://stackoverflow.com/questions/1262574/add-uipickerview-a-button-in-action-sheet-how

a Storyboard ID of SimpleTableVC . In SimpleTableViewController.h create an NSArray property that will represent the data in the table. Also in SimpleTableViewController.h create a protocol SimpleTableViewControllerDelegate with a required..

insertNewObjectForEntityForName:

http://stackoverflow.com/questions/1780929/insertnewobjectforentityforname

Xcode .xcdatamodel file editor. I created an entity called Person added a few attributes then generated a .m file to represent it. That all works fine. Now when I go to write a line of code like Person person Person NSEntityDescription insertNewObjectForEntityForName..

Dynamic (Default.png) splashscreen in 3.0 [iPhone SDK]

http://stackoverflow.com/questions/1959080/dynamic-default-png-splashscreen-in-3-0-iphone-sdk

don't intend the Default.png to be a splash screen . If you read the HIG you'll see that the Default.png is suppose to represent your user interface as it would be empty without any content. It is intended to give the user the illusion of an near instant..

Getting the bounds of an MKMapvIew

http://stackoverflow.com/questions/2081753/getting-the-bounds-of-an-mkmapview

and zooming in the map I try to get the bounds. I'm stuck on the first step which is to try to get the CGPoints that represent the SE and NW corners of the map. After that I was going to use CLLocationCoordinate2D convertPoint CGPoint point toCoordinateFromView..

Persisting Dates to SQLite3 in an iPhone Application

http://stackoverflow.com/questions/251155/persisting-dates-to-sqlite3-in-an-iphone-application

date' My question is what is the recommend approach for storing this information in a table The properties are represented as NSDate in my application but I am unsure how to represent this information in my table. It appears that SQLite3 provides.. storing this information in a table The properties are represented as NSDate in my application but I am unsure how to represent this information in my table. It appears that SQLite3 provides a DATETIME type but does not have a native understanding..

UITableView issue when using separate delegate/dataSource

http://stackoverflow.com/questions/254354/uitableview-issue-when-using-separate-delegate-datasource

provided view surface. Connect the UITableView 's dataSource and delegate outlets to File's Owner which should already represent the TableTestViewController class. Save your changes Back in Xcode add the following code to TableTestViewController.m NSInteger..

Program received signal: ???? Data Formatters temporarily unavailable

http://stackoverflow.com/questions/2813454/program-received-signal-0-data-formatters-temporarily-unavailable

in the console relates to the debugger. For some reason the debugger was unable to load the data formatters used to represent the data in the application. probably because the phone didn't have any memory left for them. share improve this answer..

apply style to range of text with javascript in uiwebview

http://stackoverflow.com/questions/2887101/apply-style-to-range-of-text-with-javascript-in-uiwebview

and that starts in one paragraph and ends in a third I can get the text nodes and the offsets within the nodes that represent the given text range. I just need a way to split a text node at an offset in the text. Currently I just apply styles to..

Using the apple FFT and accelerate Framework

http://stackoverflow.com/questions/3398753/using-the-apple-fft-and-accelerate-framework

bobbins setupReal and vDSP_fft_zrip setupReal A stride log2n FFT_FORWARD Now A will contain n 2 complex numbers. These represent n 2 frequency bins bin 1 .idealFreq 44Hz ie The lowest frequency we can reliably detect is ONE complete wave within that.. .idealFreq 512 44Hz The highest frequency we can detect known as the Nyquist frequency is where every pair of points represents a wave ie 512 complete waves within the window ie 512 44Hz or n 2 bin 1 .idealFreq Actually there is an extra Bin Bin 0..

NSDateFormatter dateFromString returns nil

http://stackoverflow.com/questions/4258266/nsdateformatter-datefromstring-returns-nil

did not explicitly set the locale the date formatter might be able to parse the date but the resulting NSDate would represent a whole other point in time. The locale identifier @ en_US_POSIX is meant for this purpose. It is guaranteed to not change..

I want to use animation to imageview using UIanimationtransitioncurl right or left. Is it possible?

http://stackoverflow.com/questions/4780488/i-want-to-use-animation-to-imageview-using-uianimationtransitioncurl-right-or-le

UIView alloc initWithFrame frame autorelease self.view addSubview self.containerView The container view can represent the images for accessibility. self.containerView setIsAccessibilityElement YES self.containerView setAccessibilityLabel..

Send and receive NSData via GameKit

http://stackoverflow.com/questions/4837102/send-and-receive-nsdata-via-gamekit

nsdata gamekit share improve this question To add on What you ought to do here is make an NSObject subclass to represent your packet and then adopt NSCoding to serialize it to an NSData in the way that you want. Doing this with a struct isn't..

iphone+Difference between nil,NIL and null

http://stackoverflow.com/questions/5908936/iphonedifference-between-nil-nil-and-null

int pointerToInt NULL char pointerToChar NULL struct TreeNode rootNode NULL NSNull is a class for objects that represent null. In fact there 䏭 only one object namely the one returned by NSNull null . It is different from nil because nil is a..

iPhone Interface Builder and Delegates

http://stackoverflow.com/questions/761814/iphone-interface-builder-and-delegates

builder share improve this question File's Owner is not a real object in the xib file. It is a proxy object. It represents the object that will become the xib's owner when it is loaded. First Responder and App Delegate are proxies also. The first.. Interface Builder. xib files contain actual serialized objects. File's Owner and First Responder are exceptions. They represent some other already existing object. File's Owner often a UIViewDelgate in non MainWindow.xib files is the chicken. The xib..

Combine static and prototype content in a table view

http://stackoverflow.com/questions/9322885/combine-static-and-prototype-content-in-a-table-view

table. Add as many UITableViewCell prototypes to the table as you need. Say one each for your static cells and one to represent the variable cells. In your datasource... #define NUMBER_OF_STATIC_CELLS 3 NSInteger tableView UITableView tableView numberOfRowsInSection..