在代码中获取当前工程的一些信息

NSBundle* mainBundle = [NSBundle mainBundle];
NSDictionary* infoDictionary =??[mainBundle infoDictionary];
NSArray* keys = [infoDictionary allKeys];
for(id key in keys)
{
????NSLog(@"key=%@ , value=%@\n",key,[infoDictionary objectForKey:key]);
}