What does this mean? "'NSUnknownKeyException', reason: … this class is not key value coding-compliant for the key X"
I'm trying to link a UILabel with an IBOutlet created in my class. My application is crashing with the following error. What does this mean? How can I fix it? *** Terminating app due to uncaught ...
I would like to check to see if I have an Internet connection on iOS using the Cocoa Touch libraries or on OSX using the Cocoa libraries. I came up with a way to do this using an NSURL. The way I did...
I know how delegates work, and I know how I can use them. But how do I create them?
I have a UIImage (Cocoa Touch). From that, I'm happy to get a CGImage or anything else you'd like that's available. I'd like to write this function: - (int)getRGBAFromImage:(UIImage *)image atX:(int)...
I am using NSDate *date = [NSDate date]; for getting the date, but the date I get is off by 2 hours.
If you have an NSMutableArray, how do you shuffle the elements randomly? (I have my own answer for this, which is posted below, but I'm new to Cocoa and I'm interested to know if there is a better wa...
I've seen in a few iPhone examples that attributes have used an underscore _ in front of the variable. Does anyone know what this means? Or how it works? An interface file I'm using looks like: @int...
I'm developing a Cocoa application, and I'm using constant NSStrings as ways to store key names for my preferences. I understand this is a good idea, because it allows easy changing of keys if necess...
It is to my understanding that one should use a forward-class declaration in the event ClassA needs to include a ClassB header, and ClassB needs to include a ClassA header to avoid any circular inclus...
How do I use an NSTimer? Can anyone give me step by step instructions?