Use of iOS UIScrollView proxy and several methods of listening in the scaling age

Use of iOS UIScrollView proxy and several methods of listening in the scaling age

There must be at least three steps:

I. Implementation Protocol

2. Establish relationships

3. Set the scaling range

For details, see the code:

 

# Import "ViewController. h" @ interface ViewController ()
 
  
// Comply with this Protocol First @ property (weak, nonatomic) IBOutlet UIScrollView * ScrollView; @ property (weak, nonatomic) IBOutlet UIImageView * minionPic; @ end @ implementation ViewController // This method is always called during the rolling process-(void) scrollViewDidScroll :( UIScrollView *) scrollView {// NSLog (@ "scrollViewDidScroll ");} // call this method when you start to scroll. When you drag it once, this method is called only once and is called once at the beginning-(void) scrollViewWillBeginDragging :( UIScrollView *) scrollView {// NSLog (@ "scrollViewWillBeg InDragging ");} // the event to be triggered when a user starts scaling actions-(void) scrollViewWillBeginZooming :( UIScrollView *) scrollView withView :( UIView *) view {NSLog (@ "scrollViewWillBeginZooming");} // which View should be set to bloom when the user scales? -(UIView *) viewForZoomingInScrollView :( UIScrollView *) scrollView {return self. minionPic;}-(void) viewDidLoad {[super viewDidLoad]; // set the content size of ScrollView contentSize self. scrollView. contentSize = self. minionPic. frame. size; // bind a proxy to establish the relationship between the ScrollView and proxy self. scrollView. delegate = self; // you can specify the zooming range as self. scrollView. minimumZoomScale = 0.2; self. scrollView. maximumZoomScale = 2.0; // Do any additional setup after loading the view, typically from a nib .} -(void) didReceiveMemoryWarning {[super didreceivemorywarning]; // Dispose of any resources that can be recreated .} @ end