1. File -> New. Choose UIViewController subclass. Tick the checkbox “With XIB for user interface”. Save it as “DatePickerViewController”.
2. Open the DatePickerViewController.xib from IB.
3. In IB, drag a UIDatePicker and a UIButton as shown below.
Note this tutorial will be updated in the near future…
1. The code below (based from the SQLiteBooks Example) will copy the database from your bundle to the “Documents” directory. You don’t have to do this every time your app launches, so there is a check at “success” below. To check this, in the iPhone Simulator navigate to the Documents directory:
1. Disable highlighted cell
cell.selectionStyle = UITableViewCellSelectionStyleNone; - or - [self.tableView deselectRowAtIndexPath:indexPath animated:NO];
1. Transparent UILabel
myLabel.backgroundColor = [UIColor clearColor];
2. Resizing an Image
CGRect rect = CGRectMake(0.0f, 0.0f, 320.0f, 460.0f); UIGraphicsBeginImageContext(CGSizeMake(320.0f, 460.0f)); [image drawInRect:rect]; UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext();
1. Trimming
NSString *strResponseTrimmed = [strResponse stringByTrimmingCharactersInSet: [NSCharacterSet whitespaceAndNewlineCharacterSet]];
2. Escaping ‘%’.
Use '%%' NSString *sqlString = [NSString stringWithFormat:@"SELECT poi_id, en_name FROM poi WHERE Upper(en_name) LIKE '%%%@%%' LIMIT 100", text];
3. Escaping for URL
NSString *bodyDirty = [NSString stringWithFormat:@"%@ %@ %@ %@ %@ %@", poi.en_name, poi.en_fullpoiadd, poi.py_fullpoiadd, poi.tel_no, poi.fax_no, poi.email]; NSString *bodyClean = [bodyDirty stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
1. Current Date
NSString *timestamp = [NSString stringWithFormat:@"%0.0f", [[NSDate date] timeIntervalSince1970]]; Or if you want the unix time as a NSString without decimals: NSString *timestamp = [NSString stringWithFormat:@"%d", (long)[[NSDate date] timeIntervalSince1970]];
1. Using the static Clang Analyzer
scan-build -k -V xcodebuild -configuration Debug -sdk iphonesimulator3.1
2. Always remove physically the files from the build directory when testing.
3. Where is the application bundle directory?
/Users/rupert/Library/Application Support/iPhone Simulator/User/Applications
1. Application Icon
Drop a Icon.png (57 x 57 pixels) in the project root directory.
2. Calling safari to launch a URL
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"http://www.apple.com"]];
3. Calling a number
- (void)callNumber:(NSString *)_number{ NSString *callToURLString = [NSString stringWithFormat:@"tel:+%@", _number]; if (![[UIApplication sharedApplication] openURL:[NSURL URLWithString:callToURLString]]) { // there was an error trying to open the URL. We'll ignore for the time being. NSLog(@"This will not work on the simulator. Need to test in the device"); } }
4. Cancelling operations
[operation cancelAllOperations] or NSArray *arrayOperations = [operationQueue operations]; for(int i=0; i < [arrayOperations count]; i++){ NSOperation *operation = (NSOperation *)[arrayOperations objectAtIndex:i]; if( [operation isExecuting] ){ NSLog(@"cancelOperations: found an operation running. Cancelling..."); [operation cancel]; } }
Apple has been releasing incremental betas in a short span of time. The ff steps would help me in documenting how to upgrade the SDK and iPhoneOS.
Part 1: iPhone SDK
1. For upgrading, we are going to choose “Custom install” into a directory “XCode3.1.3″ which I installed a few weeks ago. If you don’t change this, it will be installed in a default directory “Developer”.
1. If its alloc, copy, new. YOU ARE RESPONSIBLE for RELEASING the OBJECT (YARRO).
NSString *en_name = [[NSString alloc] initWithUTF8String:(char *)sqlite3_column_text(statement, 1)]; //do something.. set it to an object.. poi.en_name = en_name; [en_name release];