iOS开发之 小技巧

Posted 2020-07-13

转自 http://www.cocoachina.com/ios/20141229/10783.html

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.

1	self.tableView.tableFooterView = [[UIView alloc] init];

试过的都说好.

加完这句之后就变成了这样.

自定义了leftBarbuttonItem左滑返回手势失效了怎么办?

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self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc]                                          initWithImage:img                                          style:UIBarButtonItemStylePlain                                          target:self                                          action:@selector(onBack:)]; self.navigationController.interactivePopGestureRecognizer.delegate = (id<uigesturerecognizerdelegate>)self;</uigesturerecognizerdelegate>

ScrollView莫名其妙不能在viewController划到顶怎么办?

1	self.automaticallyAdjustsScrollViewInsets = NO;

键盘事件写的好烦躁,都想摔键盘了,怎么办?

1.买个结实的键盘.

2.使用IQKeyboardManager(github上可搜索),用完之后腰也不疼了,腿也不酸了.

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.

怎么在不新建一个Cell的情况下调整separaLine的位置?

1	_myTableView.separatorInset = UIEdgeInsetsMake(0, 100, 0, 0);

怎么点击self.view就让键盘收起,需要添加一个tapGestures么?

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- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {    [self.view endEditing:YES]; }

怎么给每个ViewController设定默认的背景图片?

使用基类啊,少年。

想在代码里改在xib里添加的layoutAttributes,但是怎么用代码找啊?

像拉button一样的拉你的约束.nslayoutattribute也是可以拉线的.

怎么像safari一样滑动的时候隐藏navigationbar?

1	navigationController.hidesBarsOnSwipe = Yes

导航条返回键带的title太讨厌了,怎么让它消失!

1 2	[[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60)                                                      forBarMetrics:UIBarMetricsDefault];

CoreData用起来好烦,语法又臭又长,怎么办?

MagicRecord

CollectionView 怎么实现tableview那种悬停的header?

CSStickyHeaderFlowLayou

能不能只用一个pan手势来代替UISwipegesture的各个方向?

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- (void)pan:(UIPanGestureRecognizer *)sender { typedef NS_ENUM(NSUInteger, UIPanGestureRecognizerDirection) {     UIPanGestureRecognizerDirectionUndefined,     UIPanGestureRecognizerDirectionUp,     UIPanGestureRecognizerDirectionDown,     UIPanGestureRecognizerDirectionLeft,     UIPanGestureRecognizerDirectionRight }; static UIPanGestureRecognizerDirection direction = UIPanGestureRecognizerDirectionUndefined; switch (sender.state) {     case UIGestureRecognizerStateBegan: {         if (direction == UIPanGestureRecognizerDirectionUndefined) {             CGPoint velocity = [sender velocityInView:recognizer.view];             BOOL isVerticalGesture = fabs(velocity.y) > fabs(velocity.x);             if (isVerticalGesture) {                 if (velocity.y > 0) {                     direction = UIPanGestureRecognizerDirectionDown;                 } else {                     direction = UIPanGestureRecognizerDirectionUp;                 }             }             else {                 if (velocity.x > 0) {                     direction = UIPanGestureRecognizerDirectionRight;                 } else {                     direction = UIPanGestureRecognizerDirectionLeft;                 }             }         }         break;     }     case UIGestureRecognizerStateChanged: {         switch (direction) {             case UIPanGestureRecognizerDirectionUp: {                 [self handleUpwardsGesture:sender];                 break;             }             case UIPanGestureRecognizerDirectionDown: {                 [self handleDownwardsGesture:sender];                 break;             }             case UIPanGestureRecognizerDirectionLeft: {                 [self handleLeftGesture:sender];                 break;             }             case UIPanGestureRecognizerDirectionRight: {                 [self handleRightGesture:sender];                 break;             }             default: {                 break;             }         }         break;     }     case UIGestureRecognizerStateEnded: {         direction = UIPanGestureRecognizerDirectionUndefined;            break;     }     default:         break; } }

拉伸图片的时候怎么才能让图片不变形？
1.UIImage *image = [[UIImage imageNamed:@"xxx"] stretchableImageWithLeftCapWidth:10 topCapHeight:10];

2.

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

怎么一句话添加上拉刷新？

https://github.com/samvermette/SVPullToRefresh

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[tableView addPullToRefreshWithActionHandler:^{ // prepend data to dataSource, insert cells at top of table view // call [tableView.pullToRefreshView stopAnimating] when done } position:SVPullToRefreshPositionBottom];

怎么把tableview里cell的小对勾的颜色改成别的颜色？

1	_mTableView.tintColor = [UIColor redColor];

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？

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- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated {     [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent]; }

怎么把我的navigationbar弄成透明的而不是带模糊的效果？

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[self.navigationBar setBackgroundImage:[UIImage new]                          forBarMetrics:UIBarMetricsDefault]; self.navigationBar.shadowImage = [UIImage new]; self.navigationBar.translucent = YES;

怎么改变uitextfield placeholder的颜色和位置？

继承uitextfield，重写这个方法

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- (void) drawPlaceholderInRect:(CGRect)rect {     [[UIColor blueColor] setFill];     [self.placeholder drawInRect:rect withFont:self.font lineBreakMode:UILineBreakModeTailTruncation alignment:self.textAlignment]; }

你为什么知道这么多奇怪的花招？

去stackoverflow刷问题啊，少年！