CODEWITHSUNDEEP
objective-ccocoakey-value-coding
Meltemi
Meltemi

Reputation: 38359

Objective-C dot syntax tricks for when Key-Value won't work?

I'm iterating through some objects and trying to set some properties that, apparently, don't like Key-Value coding. so I'm unable to create a string at runtime to represent the "key".

This line of ViewController won't compile: 

[self setValue:offsetX forKeyPath:[NSString stringWithFormat:@"myView%d.center.x", anInt]];

but I can set these properties with dot notation in a ridiculous switch statement:

myView1.center.x = offsetX;

Is there another way to go about this? perhaps create an accessor like myView(i).center.x ? Knowing full well it was going to be futile, i even tried: [NSString stringWithFormat:@"myView%d", anInt].center.x
to no avail...

Upvotes: 1

Views: 546

Answers (1)

Peter N Lewis
Peter N Lewis

Reputation: 17811

The reason it wont compile is presumably because offsetX is an int or float, not an NSNumber (it would be helpful to give the compiler error message in your question).

However KVC and setValue:forKeyPath: is very clever and will automatically convert from an NSNumber for you, so use:

[self setValue:[NSNumber numberWithInt:offsetX] forKeyPath:[NSString stringWithFormat:@"myView%d.center.x", anInt]];

(or numberWithFloat as appropriate).

Upvotes: 3

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