BOOL issue in Objective-C
When I'm trying to do this to get the BOOL from a dictionary, I get:
BOOL isTrue = [someDict objectForKey: @"isTrue"];
I get:
Initialization makes integer from pointer without a cast
I set the dictionary by doing this:
self.someDict = [[NSMutableDictionary alloc]
initWithObjectsAndKeys:
self.isTrue, @"isTrue",
nil];
开发者_StackOverflowAny ideas?
Use:
BOOL isTrue = [[someDict objectForKey:@"isTrue"] boolValue];
The only way to store a BOOL
in an NSDictionary
is to box it in an NSNumber
object. A BOOL
is primitive, and a dictionary only holds objects.
Similarly, to store a BOOL
in a dictionary, use:
[someDict setObject:[NSNumber numberWithBool:isTrue] forKey:@"isTrue"];
EDIT: (in response to a comment)
There are two ways of representing this as an @property
. One is to declare the ivar as a BOOL
, and the other is to declare it as an NSNumber
.
For the first case, the ivar is: BOOL isTrue;
, and the property is @property BOOL isTrue;
(I'm ignoring naming conventions, obviously).
For the NSNumber
, the ivar is: NSNumber * isTrue;
and the property is @property (nonatomic, retain) NSNumber * isTrue;
. If you go with this route, you might want to provide a second setter method (setIsTrueBool
or something) that allows you to just pass in YES
or NO
, and then you do the boxing yourself. Otherwise anyone who calls this would have to do the boxing themselves.
I'd personally most likely go with option #1, but it really depends on what the class's purpose was.
精彩评论