Heres some example code that will attempt to compress an image for you so that it doesn’t exceed either a max compression or maximum file size CGFloat compression = 0.9f; CGFloat maxCompression = 0.1f; int maxFileSize = 250*1024; NSData *imageData = UIImageJPEGRepresentation(yourImage, compression); while ([imageData length] > maxFileSize && compression > maxCompression) { compression -= … Read more
You can use +[UIColor colorWithPatternImage:] to produce a patterned background. Example (bring your own CGGradient): // Allocate color space CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); // Allocate bitmap context CGContextRef bitmapContext = CGBitmapContextCreate(NULL, 320, 480, 8, 4 * 320, colorSpace, kCGImageAlphaNoneSkipFirst); //allocate myGradient CGFloat locationList[] = {0.0f, 1.0f}; CGFloat colorList[] = {0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, … Read more
You can. Skype does this. You presumably need to set <key>UIBackgroundModes</key><array><string>audio</string></array> in Info.plist, and you need to make sure that the audio session is active/running/whatever before you switch apps (the assumption is that you won’t suddenly start recording/playing music/whatever when your app is in the background). The docs say that “audio” lets you play audio … Read more
The iOS SDK does not allow you to change/animate your apps icon. Apple’s own apps are ofcourse an exception.
You can “trim” the text, that is remove all the whitespace at the start and end. If all that’s left is an empty string, then only whitespace (or nothing) was entered. NSString *rawString = [textField text]; NSCharacterSet *whitespace = [NSCharacterSet whitespaceAndNewlineCharacterSet]; NSString *trimmed = [rawString stringByTrimmingCharactersInSet:whitespace]; if ([trimmed length] == 0) { // Text was … Read more
You can “trim” the text, that is remove all the whitespace at the start and end. If all that’s left is an empty string, then only whitespace (or nothing) was entered. NSString *rawString = [textField text]; NSCharacterSet *whitespace = [NSCharacterSet whitespaceAndNewlineCharacterSet]; NSString *trimmed = [rawString stringByTrimmingCharactersInSet:whitespace]; if ([trimmed length] == 0) { // Text was … Read more
You should be able to use any of those fonts, provided you know the appropriate name. There are calls to enumerate the font families and individual fonts in those families on the phone, but a complete listing is available on this site.
The only free library to do this is Cocoa-Touch-Barcodes, which is a fork of cocoabarcodes. If you are considering commercial libraries, there is one called iPhone Barcode Generator. update Check this objective-c port of ZXing: https://github.com/TheLevelUp/ZXingObjC
I’m afraid what you are trying to do will not work. I have tried to achieve the same thing. The problem is the difference in scanning in foreground and background. When you are scanning for devices in the foreground you can scan for anything. In the background you must specify the actual service UUID you … Read more
You could create an image programmatically and so have the ability to use your colors in a dynamic way: Create a category for UIButton with this method and be sure to have QuartzCore lib imported via @import QuartzCore: – (void)setColor:(UIColor *)color forState:(UIControlState)state { UIView *colorView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 1, 1)]; colorView.backgroundColor = color; … Read more