ios禁止页面左划返回

方法一：id traget = self.navigationController.interactivePopGestureRecognizer.delegate;
UIPanGestureRecognizer * pan = [[UIPanGestureRecognizer alloc]initWithTarget:traget action:nil];
[self.view addGestureRecognizer:pan];

方法二：//在viewdidappear里面 禁用返回手势
if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {
self.navigationController.interactivePopGestureRecognizer.enabled = NO;
}