How do I set up an UIScreenEdgePanGestureRecognizer using Interface Builder?

Question

I can\'t get UIScreenEdgePanGestureRecognizer to work when I create when I add it to my view controller using Interface Builder, so I\'m asking here to establish wh

Answer 1

I set up a project to test your question and found the same issue you did. Here are the scenarios I set up to test:

• I did exactly as you did, using Interface Builder, to build the screen edge gesture. The only difference in my code is that I put a line of code in the selector so the debugger would have something to stop on. The debugger failed to halt exactly as you found.

  -(void)handlePan:(id)sender
  {
      NSString *test = @"";
  }
  

• I then created an additional gesture using the pinch gesture on the same view using Interface Builder and I was able to get the debugger to halt within that selector. So Interface Builder seems to be able to build other gestures correctly.

• I then created the screen edge gesture manually using the following code and it worked as expected.

In the ViewController.h file I included the UIGestureRecognizerDelegate.

@interface ViewController : UIViewController <UIGestureRecognizerDelegate>
@end

In the ViewController.m file I implemented the gesture manually.

#import "ViewController.h"

@interface ViewController ()

-(void)handlePan:(id)sender;

@end

@implementation ViewController

- (void)viewDidLoad 
{
    [super viewDidLoad];
    UIScreenEdgePanGestureRecognizer *pan = [[UIScreenEdgePanGestureRecognizer alloc] initWithTarget:self
                                                                                              action:@selector(handlePan:)];
    [pan setEdges:UIRectEdgeLeft];
    [pan setDelegate:self];
    [self.view addGestureRecognizer:pan];
}

-(void)handlePan:(id)sender
{
    NSString *test = @"";
}

@end

I ended up with the same conclusion you did - there seems to be something wrong with the Interface Builder's implementation of the UIScreenEdgePanGestureRecognizer.