How to convert CFStringRef to NSString?

How to convert CFStringRef to NSString?

1. If you are using ARC, the new casting syntax for this case is now NSString *aNSString = (__bridge NSString *)aCFString.
2. Thanks MikeG, I had to do similar for the reverse conversion: NSString *str=@”abc”; CFStringRef cstrref=(__bridge CFStringRef)str;

What is CFString in Swift?

CFString is an opaque type that defines the characteristics and behavior of CFString objects. Values of type CFStringRef may refer to immutable or mutable strings, as CFMutableString objects respond to all functions intended for immutable CFString objects.

What is CFData?

CFData is “toll-free bridged” with its Cocoa Foundation counterpart, NSData . What this means is that the Core Foundation type is interchangeable in function or method calls with the bridged Foundation object.

What is Cfarrayref?

A reference to an immutable array object.

How do I append to NSString?

The format specifier “%@” is used to insert string values. The example below uses a combination of whitespace and %@ format specifiers to append two strings to string1: NSString * string3 = [string1 stringByAppendingFormat:@” %@ %@”, string2, @”A third string.

What is CFData Swift?

Overview. CFData and its derived mutable type, CFMutableData, provide support for data objects, object-oriented wrappers for byte buffers. Data objects let simple allocated buffers (that is, data with no embedded pointers) take on the behavior of Core Foundation objects.

What is SecItemCopyMatching?

SecItemCopyMatching(_:_:) Returns one or more keychain items that match a search query, or copies attributes of specific keychain items.

What is CFDictionary in Swift?

CFDictionary provides functions for querying the values of a dictionary. function lets you apply a function to all key-value pairs in a dictionary. CFDictionary is “toll-free bridged” with its Cocoa Foundation counterpart, NSDictionary .

How do I append multiple strings in Objective C?

iPhone Development 101: Concatenating and Appending Strings. To concatenate two strings into a new string: NSString *string1 = @”This is”; NSString *string2 = @” a test. “; NSString *string3 = [string1 stringByAppendingString:string2]; // string3 is now @”This is a test.” string1 and string2 are unchanged.

Is it possible to change the contents of NSString?

Instances of the class NSString are immutable – their contents cannot be changed. Once a string has been initialized using NSString, the only way to append text to the string is to create a new NSString object.

How do you add strings to NSString in Objective C?

In most cases, this is accomplished using an addition or concatenation operator. However, you do not do it this way in Objective-C. Strings in Objective-C are handled using the classes NSString and NSMutableString, and require a little more effort to work with on the part of the programmer.

How to cast a NSString to a CFString?

On the other way around you can cast a NSString *to a CFStringusing a __bridge_retainedcast, so that you will own the object and you’ll have to explicitly release it by using CFRelease. To wrap it up you can have NSString → CFString // Don’t transfer ownership.

How do you append text to NSString object?

Once a string has been initialized using NSString, the only way to append text to the string is to create a new NSString object. While doing so, you can append string constants, NSString objects, and other values. The NSString class contains several methods that you can use for this purpose.