Remove @“” from NSString or typecast NSString into variable name

Question

I read a NSString from file and then I want to #define this as a UIColor so I can quickly change color\'s.

I want something to work like so:

#define GRAY         


        

Answer 1

When you say 'read from file the string : @"GRAY"' do you mean at application run time? if so, then you cannot use #define(s), which are happening at compile time.

Answer 2

You could load the colors into a NSDictionary.

// Put this in some global scope
NSDictionary *colors = [NSDictionary dictionaryWithObjectsAndKeys: 
    [UIColor darkGrayColor], @"GRAY", nil];

// using the dictionary
myController.view.backgroundColor = [colors objectForKey:kColor];

Answer 3

You can't do that. Objective-C is a compiled language, so you can't use a NSString as if it were a piece of code. You will need a way to return a proper color from a string/NSString read from a file.

Answer 4

Daniel's answer is probably the best. Since he hasn't provided any code, this is one implementation:

-(UIColor*) colorFromString: (NSString*) colorName
{
    static NSDictionary colors = nil;
    if (colors == nil)
    {
        colors = [NSDictionary dictionaryWithObjectsAndKeys: 
                                   [UIColor darkGreyColor], @"GRAY",
                                   [UIColor blueColor], @"BLUE",
                                   // etc
                                   nil];
        [colors retain];
    }
    return [colors objectForKey: colorName];
}