[email protected]___,他结合自身的实践开发经验总结出了22个iOS开发的小技巧,以非常欢乐的语调轻松解决开发过程中所遇到的各种苦逼难题,光读着便已忍俊不禁。

1.TableView不显示没内容的Cell怎么办?

类似于图1,我不想让下面的那些空显示。很简单,添加“self.tableView.tableFooterView = [[UIView alloc] init];”试过都说好,加完这句之后就变成了图2的样子。

2.自定义了leftBarbuttonItem左滑返回手势失效了怎么办?

self.navigationItem.leftBarButtonItem=[[UIBarButtonItemalloc]

initWithImage:img

style:UIBarButtonItemStylePlain

target:self

action:@selector(onBack:)];

self.navigationController.interactivePopGestureRecognizer.delegate=(id<UIGestureRecognizerDelegate>)self;

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

self.automaticallyAdjustsScrollViewInsets=NO;

4. 键盘事件写得好烦躁,都想摔键盘了怎么办?

●买个结实的键盘;

●使用IQKeyboardManager(GitHub上可搜索),用完之后腰也不疼了,腿也不酸了。

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上搬运吧。

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*)toucheswithEvent:(UIEvent*)event

{

[self.viewendEditing:YES];

}

8. 怎么给每个ViewController设定默认的背景图片?

使用基类啊,少年。

9.想在代码里改在xib里添加的layoutAttributes,但该怎么用代码找?

像拉Button一样地拉你的约束,nslayoutattribute也是可以拉线的。

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?

[[UIBarButtonItemappearance]setBackButtonTitlePositionAdjustment:UIOffsetMake(0,-60)

forBarMetrics:UIBarMetricsDefault];

12. CoreData用起来好烦,语法又臭又长怎么办?

MagicRecord

13. CollectionView怎么实现tableview那种悬停的header?

CSStickyHeaderFlowLayout

14.能不能只用一个pan手势来代替UISwipegesture的各个方向?

-(void)pan:(UIPanGestureRecognizer*)sender

{

typedefNS_ENUM(NSUInteger,UIPanGestureRecognizerDirection){

UIPanGestureRecognizerDirectionUndefined,

UIPanGestureRecognizerDirectionUp,

UIPanGestureRecognizerDirectionDown,

UIPanGestureRecognizerDirectionLeft,

UIPanGestureRecognizerDirectionRight

};

staticUIPanGestureRecognizerDirectiondirection=UIPanGestureRecognizerDirectionUndefined;

switch(sender.state){

caseUIGestureRecognizerStateBegan:{

if(direction==UIPanGestureRecognizerDirectionUndefined){

CGPointvelocity=[sendervelocityInView:recognizer.view];

BOOLisVerticalGesture=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;

}

caseUIGestureRecognizerStateChanged:{

switch(direction){

caseUIPanGestureRecognizerDirectionUp:{

[selfhandleUpwardsGesture:sender];

break;

}

caseUIPanGestureRecognizerDirectionDown:{

[selfhandleDownwardsGesture:sender];

break;

}

caseUIPanGestureRecognizerDirectionLeft:{

[selfhandleLeftGesture:sender];

break;

}

caseUIPanGestureRecognizerDirectionRight:{

[selfhandleRightGesture:sender];

break;

}

default:{

break;

}

}

break;

}

caseUIGestureRecognizerStateEnded:{

direction=UIPanGestureRecognizerDirectionUndefined;

break;

}

default:

break;

}

}

15. 拉伸图片的时候怎么才能让图片不变形?

方法一:

UIImage*image=[[UIImageimageNamed:@"xxx"]stretchableImageWithLeftCapWidth:10topCapHeight:10

注:有开发者提醒这个已经弃用,现在的方法叫resizableImageWithCapInsets。

方法二,如图:

16.怎么播放GIF的时候这么卡,有没有好点的库?

FlipBoard出品的FLAnimatedImage太适合你了。

17.怎么一句话添加上拉刷新?

使用SVPullToRefresh库:

[tableViewaddPullToRefreshWithActionHandler:^{

//prependdatatodataSource,insertcellsattopoftableview

//call[tableView.pullToRefreshViewstopAnimating]whendone

}position:SVPullToRefreshPositionBottom];

18. 怎么把tableview里Cell的小对勾颜色改成别的颜色?

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*)navigationControllerwillShowViewController:(UIViewController*)viewControlleranimated:(BOOL)animated

{

[[UIApplicationsharedApplication]setStatusBarStyle:UIStatusBarStyleLightContent];

}

20. 怎么把我的navigationbar弄成透明的而不是带模糊的效果?

[self.navigationBarsetBackgroundImage:[UIImagenew]

forBarMetrics:UIBarMetricsDefault];

self.navigationBar.shadowImage=[UIImagenew];

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{

[[UIColorblueColor]setFill];

[self.placeholderdrawInRect:rectwithFont:self.fontlineBreakMode:UILineBreakModeTailTruncationalignment:self.textAlignment];

}

22. 你为什么知道这么多奇怪的花招?

去Stack Overflow刷问题啊,少年!