Trying to pass CGrect to performSelector withObject
I'm trying to pass a CGRect:
SEL frameSel = NSSelectorFromString(@"setFrame:");
CGRect rect = CGRectMake(10, 10, 200, 100);
[object performSelector:frameSel withObject:rect ];
But this does not compile
I also tried:
SEL frameSel = NSSelectorFromString(@"setFrame:");
CGRect rect = CGRectMake(10, 10, 200, 100);
NSValue * value = [NSValue valueWithCGRect:rect];
[object performSelector:frameSel withObject:value ];
Actually, this does compile but when I debug, the frame is not setted correctly:
po object
<UILabel: 0x39开发者_如何学JAVA220f0; frame = (0 0; 200 100); text = 'reflectionLabel'; clipsToBounds = YES; userInteractionEnabled = NO; layer = <CALayer: 0x3922240>>
But it should be frame = (10 10; 200 100)
How can I solve this problem?
Thank you in advance!
CGRect rect = CGRectMake(10, 10, 200, 100); [object performSelector:frameSel withObject:rect ];
But this does not compile
Correct, because rect
is a structure, not a pointer to an object.
CGRect rect = CGRectMake(10, 10, 200, 100); NSValue * value = [NSValue valueWithCGRect:rect]; [object performSelector:frameSel withObject:value ];
Actually, this does compile but when I debug, the frame is not setted correctly:
po object <UILabel: 0x39220f0; frame = (0 0; 200 100); text = 'reflectionLabel'; clipsToBounds = YES; userInteractionEnabled = NO; layer = <CALayer: 0x3922240>>
Well, it's not garbage, so it would seem that it worked, even though the origin somehow remained zero. You may want to ask a separate question about that.
Anyway, why are you using performSelector:withObject:
? You're not addressing it to a specific thread and you're not putting it on a delay; why not simply say object.frame = rect
?
You must use an NSInvocation to handle any non-id arguments or return values:
CGRect rect = CGRectMake(104, 300, 105, 106);
UIView *view = [[UIView alloc] init];
NSMethodSignature *methodSig = [view methodSignatureForSelector:@selector(setFrame:)];
NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:methodSig];
invocation.target = view;
invocation.selector = @selector(setFrame:);
[invocation setArgument:&rect atIndex:2];
[invocation invoke];
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