转自: http://blog.csdn.net/jasonblog/article/details/16867587
在iOS 7还没有发布的时候,各种App实现各种的swipe to pop效果,比如这里有一份简单的demo。 在iOS 7上,只要是符合系统的导航结构: - - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
- {
- self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
-
- self.viewController = [[[ViewController alloc] initWithNibName:@"ViewController" bundle:nil] autorelease];
- self.navController = [[[UINavigationController alloc] initWithRootViewController:self.viewController] autorelease];
- self.window.rootViewController = self.navController;
- [self.window makeKeyAndVisible];
- return YES;
- }
就能够拥有原生的漂亮效果:
遗憾的是目前项目代码里没有遵循iOS系统的导航结构,使得无法利用这点好处。所以我考虑使用新增的UIScreenEdgePanGestureRecognizer手势: - if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.0")) {
- UIScreenEdgePanGestureRecognizer *left2rightSwipe = [[[UIScreenEdgePanGestureRecognizer alloc]
- initWithTarget:self
- action:@selector(handleSwipeGesture:)]
- autorelease];
- [left2rightSwipe setDelegate:self];
- [left2rightSwipe setEdges:UIRectEdgeLeft];
- [self.view addGestureRecognizer:left2rightSwipe];
- }
- }
-
- - (void)handleSwipeGesture:(UIScreenEdgePanGestureRecognizer *)gestureRecognizer
- {
- [self.navigationController popViewControllerAnimated:YES];
- }
刚加上去的时候各种无法触发,很郁闷——毕竟是在既有代码添加,而不是在一个干净的工程上。后来发现现有代码实现了是否开始解释touch的代理函数,稍作修改得以生效: - - (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
- {
- if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.0")) {
- if ([gestureRecognizer isKindOfClass:[UIScreenEdgePanGestureRecognizer class]]) {
- return YES;
- }
- }
生效了以后但是体验不好,感觉不灵敏。原来是已经添加过tapGesture,受了影响,又做了进一步修改:- - (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldBeRequiredToFailByGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
- {
- BOOL result = NO;
-
- if ([gestureRecognizer isKindOfClass:[UIScreenEdgePanGestureRecognizer class]]) {
- result = YES;
- }
-
- return result;
- }
如此一番才觉得尚可。上面这个代理函数的描述如下: - Asks the delegate if a gesture recognizer should be required to fail by another gesture recognizer.
gestureRecognizer和otherGestureRecognizer之间到底是怎样的一个影响关系呢?
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