What you really want is a method such as (BOOL)networkIsAvailable, returning YES or NO. Apple made it several megabytes long and requires you to study several years before you get to YES or NO. I hate that! This is such a basic function on an always-connected device that I find it appalling not to have […]
Once you have a reference to the file in question you can call the removeItemAtPath method: // get reference with path and filename NSString *filePath = [[NSString alloc]initWithFormat:@”Documents/myFile.txt”]; NSString *deleteThis = [NSHomeDirectory()stringByAppendingPathComponent:filePath]; // now delete the file [[NSFileManager defaultManager]removeItemAtPath:deleteThis error:nil]; This does not work with wildcards in the file name (for example *.jpg).
You can see the full directory under ~Library/Application Support/iPhone Simulator You’ll be presented with a list of iOS Versions, each of which has several folders to explore. To access data that your apps have written, head over to Applications and see a list of cryptic folders, each one corresponding to one of your apps. In […]
Imagine we had a file that we’ve saved: NSString *myFile = [NSHomeDirectory() stringByAppendingPathComponent:@”Documents/myFile.txt”]; Before accessing it we can determine if it exists or not: BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:[NSHomeDirectory()stringByAppendingPathComponent:myFile]];
When a new iOS version comes out, developers can get pre-release Beta Versions to test their apps. New betas can be installed over the air, but if the release version comes out then there’s no over the air upgrade for those. Instead, it appears that you already have the latest version installed – even though […]
Timers are good if you want to delay executing a method, or if you need to call a method repeatedly. To set a one-off timer without setting a property you can use this: // calls the updateLabel method in 5 seconds [NSTimer scheduledTimerWithTimeInterval:5.0 target:self selector:@selector(updateLabel) userInfo:nil repeats:NO]; However, you won’t be able to stop it […]
The UIImagePickerController can help us do this with ease. In this example we’ll instantiate it, then we tell it what kind of image we want returned (we’re using an edited version here, but we could just as well return the original, or start using a camera). Next we present a modal view controller where the […]
// first we get the path to our image NSString *imagePath = [NSHomeDirectory() stringByAppendingPathComponent:@”Documents/myImage.jpg”]; // now we can load and display the file like this self.myPicture.image = [UIImage imageWithContentsOfFile:imagePath];
