iOS开发中的奇葩技巧
TableView不显示没内容的Cell怎么办?
类似这种,我不想让下面那些空的显示.
很简单.
self.tableView.tableFooterView = [[UIView alloc] init];
加完这句之后就变成了这样.
2 、自定义了leftBarbuttonItem左滑返回手势失效了怎么办?
self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithImage:img style:UIBarButtonItemStylePlain target:self action:@selector(onBack:)]; self.navigationController.interactivePopGestureRec ognizer.delegate = (id)self;
3、ScrollView莫名其妙不能在viewController划到顶怎么办?
self.automaticallyAdjustsScrollViewInsets = NO;
4、键盘事件写的好烦躁,都想摔键盘了,怎么办?
5、为什么我的app老是不流畅,到底哪里出了问题?
如图
这个神器叫做:KMCGeigerCounter,快去github搬运吧.
6、怎么在不新建一个Cell的情况下调整separaLine的位置?
_myTableView.separatorInset = UIEdgeInsetsMake(0, 100, 0, 0);
7、怎么点击self.view就让键盘收起,需要添加一个tapGestures么?
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { [self.view endEditing:YES]; }
8、怎么给每个ViewController设定默认的背景图片?
9、想在代码里改在xib里添加的layoutAttributes,但是怎么用代码找啊?
10、怎么像safari一样滑动的时候隐藏navigationbar?
navigationController.hidesBarsOnSwipe = Yes;
11、导航条返回键带的title太讨厌了,怎么让它消失!
[[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60) forBarMetrics:UIBarMetricsDefault];
12、CoreData用起来好烦,语法又臭又长,怎么办?
13、CollectionView 怎么实现tableview那种悬停的header?
使用 CSStickyHeaderFlowLayou
14、能不能只用一个pan手势来代替UISwipegesture的各个方向?
- (void)pan:(UIPanGestureRecognizer *)sender { typedef NS_ENUM(NSUInteger, UIPanGestureRecognizerDirection) { UIPanGestureRecognizerDi rectionUndefined, UIPanGestureRecognizerDi rectionUp, UIPanGestureRecognizerDi rectionDown, UIPanGestureRecognizerDi rectionLeft, UIPanGestureRecognizerDi rectionRight }; static UIPanGestureRecognizerDi rection direction = UIPanGestureRecognizerDi rectionUndefined; switch (sender.state) { case UIGestureRecognizerState Began: { if (direction == UIPanGestureRecognizerDi rectionUndefined) { CGPoint velocity = [sender velocityInView:recognizer.view]; BOOL isVerticalGesture = fabs(velocity.y) > fabs(velocity.x); if (isVerticalGesture) { if (velocity.y > 0) { direction = UIPanGestureRecognizerDi rectionDown; } else { direction = UIPanGestureRecognizerDi rectionUp; } } else { if (velocity.x > 0) { direction = UIPanGestureRecognizerDi rectionRight; } else { direction = UIPanGestureRecognizerDi rectionLeft; } } } break; } case UIGestureRecognizerState Changed: { switch (direction) { case UIPanGestureRecognizerDi rectionUp: { [self handleUpwardsGesture:sender]; break; } case UIPanGestureRecognizerDi rectionDown: { [self handleDownwardsGesture:sender]; break; } case UIPanGestureRecognizerDi rectionLeft: { [self handleLeftGesture:sender]; break; } case UIPanGestureRecognizerDi rectionRight: { [self handleRightGesture:sender]; break; } default: { break; } } break; } case UIGestureRecognizerState Ended: { direction = UIPanGestureRecognizerDi rectionUndefined; break; } default: break; } }
15、拉伸图片的时候怎么才能让图片不变形?
UIImage *image = [[UIImage imageNamed:@"xxx"] stretchableImageWithLeftCapWidth:10 topCapHeight:10];
2)
16、怎么播放GIF的时候这么卡,有没有好点的库?
FlipBoard出品的太适合你了:https://github.com/Flipboard/FLAnimatedImage
17、怎么一句话添加上拉刷新?
https://github.com/samvermette/SVPullToRefresh
[tableView addPullToRefreshWithActionHandler:^{ // prepend data to dataSource, insert cells at top of table view // call [tableView.pullToRefreshView stopAnimating] when done } position:SVPullToRefreshPositionB ottom];
18、怎么把tableview里cell的小对勾的颜色改成别的颜色?
_mTableView.tintColor
19、本来我的statusbar是lightcontent的,结果用UIImagePickerController会导致我的statusbar的样式变成黑色,怎么办?
- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated { [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent]; }
20、怎么把我的navigationbar弄成透明的而不是带模糊的效果?
[self.navigationBar setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault]; self.navigationBar.shadowImage = [UIImage new]; self.navigationBar.translucent = YES;
21、怎么改变uitextfield placeholder的颜色和位置?
继承uitextfield,重写这个方法
- (void) drawPlaceholderInRect:(CGRect)rect { [[UIColor blueColor] setFill]; [self.placeholder drawInRect:rect withFont:self.font lineBreakMode:UILineBreakModeTailTruncation alignment:self.textAlignment]; }