1.删除某个view所有的子视图
[[someView subviews]
makeObjectsPerformSelector:@selector(removeFromSuperview)];
2.删除NSUserDefaults所有记录
//方法一
NSString *appDomain = [[NSBundle mainBundle] bundleIdentifier];
[[NSUserDefaults standardUserDefaults] removePersistentDomainForName:appDomain];
//方法二
- (void)resetDefaults {
NSUserDefaults * defs = [NSUserDefaults standardUserDefaults];
NSDictionary * dict = [defs dictionaryRepresentation];
for (id key in dict) {
[defs removeObjectForKey:key];
}
[defs synchronize];
}
// 方法三
[[NSUserDefaults standardUserDefaults] setPersistentDomain:[NSDictionary dictionary] forName:[[NSBundle mainBundle] bundleIdentifier]];
3.禁用系统滑动返回功能
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {self.navigationController.interactivePopGestureRecognizer.delegate = self;
}
}
- (void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {self.navigationController.interactivePopGestureRecognizer.delegate = nil;
}
}
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
return NO;
}
4.模拟器报错
解决办法：
打开模拟器->Simulator->Reset Content and Settings...
如果不行，就重启试试！
5.自定义cell选中背景颜色
UIView *bgColorView = [[UIView alloc] init];
bgColorView.backgroundColor = [UIColor redColor];
[cell setSelectedBackgroundView:bgColorView];
6.UIView背景颜色渐变
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 100)];
[self.view addSubview:view];
CAGradientLayer *gradient = [CAGradientLayer layer];
gradient.frame = view.bounds;
gradient.colors = [NSArray arrayWithObjects:(id)[[UIColor blackColor] CGColor], (id)[[UIColor whiteColor] CGColor], nil];
[view.layer insertSublayer:gradient atIndex:0];
7.停止UIView动画
[yourView.layer removeAllAnimations]
8.为UIView某个角添加圆角
// 左上角和右下角添加圆角
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:view.bounds byRoundingCorners:(UIRectCornerTopLeft | UIRectCornerBottomRight) cornerRadii:CGSizeMake(20, 20)];
CAShapeLayer *maskLayer = [CAShapeLayer layer];
maskLayer.frame = view.bounds;
maskLayer.path = maskPath.CGPath;
view.layer.mask = maskLayer;
9.将一个view放置在其兄弟视图的最上面
[parentView bringSubviewToFront:yourView]
10.将一个view放置在其兄弟视图的最下面
[parentView sendSubviewToBack:yourView]
11.获取view的坐标在整个window上的位置
// v上的(0, 0)点在toView上的位置
CGPoint point = [v convertPoint:CGPointMake(0, 0) toView:[UIApplication sharedApplication].windows.lastObject];
或者
CGPoint point = [v.superview convertPoint:v.frame.origin toView:[UIApplication sharedApplication].windows.lastObject];
12.获取一个view所属的控制器
// view分类方法
- (UIViewController *)belongViewController {
for (UIView *next = [self superview]; next; next = next.superview) {
UIResponder* nextResponder = [next nextResponder];
if ([nextResponder isKindOfClass:[UIViewController class]]) {
return (UIViewController *)nextResponder;
}
}
return nil;
}
13.scrollView滚动到最下边
CGPoint bottomOffset = CGPointMake(0, scrollView.contentSize.height - scrollView.bounds.size.height);
[scrollView setContentOffset:bottomOffset animated:YES];