自学知识(四)

1.解决循环引用:

__weak __typeof(self) weakSelf = self;

2.设置segmentedControl:

1     NSArray *segmentedArray = [[NSArray alloc]initWithObjects:@"国内",@"国外",nil];
2     _segmentedControl = [[UISegmentedControl alloc]initWithItems:segmentedArray];
3     _segmentedControl.frame = CGRectMake(0,0,180,30);
4     _segmentedControl.tintColor = TheThemeColor;
5     [_segmentedControl setSelectedSegmentIndex:0];
6     [_segmentedControl addTarget:self action:@selector(segmentedControlAction:) forControlEvents:UIControlEventValueChanged];
7     self.navigationItem.titleView = _segmentedControl;

3.学会使用子控制器:

1 _chinaVC = [[PickChinaCityController alloc] init];
2     _overseasVC = [[PickOverseasController alloc] init];
3
4     [self addChildViewController:_chinaVC];
5     [self addChildViewController:_overseasVC];

4.设置控制器的动画:

 1 #pragma mark - 取消操作
 2 - (void)cancelAction{
 3
 4     CATransition *animation = [CATransition animation];
 5     animation.duration = 0.5;
 6     animation.timingFunction = UIViewAnimationCurveEaseInOut;
 7     animation.type = @"pageUnCurl";
 8     animation.type = kCATransitionFade;
 9     //    animation.subtype = kCATransitionFromBottom;
10     [self.view.window.layer addAnimation:animation forKey:nil];
11
12     [self dismissViewControllerAnimated:NO completion:^{
13
14     }];
15 }

5.给导航栏去阴影:

 1 - (void)viewWillAppear:(BOOL)animated{
 2     [super viewWillAppear:animated];
 3
 4     if (iOS7) {
 5         self.edgesForExtendedLayout = UIRectEdgeAll;
 6         self.automaticallyAdjustsScrollViewInsets = YES;
 7         self.extendedLayoutIncludesOpaqueBars = NO;
 8     }
 9     [self.navigationController.navigationBar setTranslucent:YES];
10
11     //为什么要加这个呢，shadowImage 是在ios6.0以后才可用的。但是发现5.0也可以用。不过如果你不判断有没有这个方法，
12     //而直接去调用可能会crash，所以判断下。作用：如果你设置了上面那句话，你会发现是透明了。但是会有一个阴影在，下面的方法就是去阴影
13     if ([self.navigationController.navigationBar respondsToSelector:@selector(shadowImage)])
14     {
15         [self.navigationController.navigationBar setShadowImage:[[UIImage alloc] init]];
16     }
17     //以上面4句是必须的,但是习惯还是加了下面这句话
18     [self.navigationController.navigationBar setBackgroundColor:[UIColor clearColor]];
19
20 }