iOS開發的小技巧

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轉自簡書：http://www.jianshu.com/p/50b63a221f09  http://www.jianshu.com/p/08f194e9904c 

原葉孤城___ 

self.tableView.tableFooterView = [[UIView alloc] init];
試過的都說好.

加完這句之後就變成了這樣.

 自訂了leftBarbuttonItem左滑返回手勢失效了怎麼辦?

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

ScrollView莫名其妙不能在viewController划到頂怎麼辦?

self.automaticallyAdjustsScrollViewInsets = NO;

鍵盤事件寫的好煩躁,都想摔鍵盤了,怎麼辦?

1. 買個結實的鍵盤.
2. 使用IQKeyboardManager(github上可搜尋),用完之後腰也不疼了,腿也不酸了.

為什麼我的app老是不流暢,到底哪裡出了問題?

 

這個神器叫做:KMCGeigerCounter
快去github搬運吧.

怎麼在不建立一個Cell的情況下調整separaLine的位置?

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

怎麼點擊self.view就讓鍵盤收合,需要添加一個tapGestures麼?

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

怎麼給每個ViewController設定預設的背景圖片?

使用基類啊,少年.

想在代碼裡改在xib裡添加的layoutAttributes,但是怎麼用代碼找啊?

像拉button一樣的拉你的約束.nslayoutattribute也是可以拉線的.

怎麼像safari一樣滑動的時候隱藏navigationbar?

navigationController.hidesBarsOnSwipe = Yes

導航條返回鍵帶的title太討厭了,怎麼讓它消失!

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

CoreData用起來好煩,文法又臭又長,怎麼辦?

MagicalRecord

CollectionView 怎麼實現tableview那種懸停的header?

CSStickyHeaderFlowLayout

文／葉孤城___（簡書作者）
原文連結：http://www.jianshu.com/p/50b63a221f09
著作權歸作者所有，轉載請聯絡作者獲得授權，並標註“簡書作者”。能不能只用一個pan手勢來代替UISwipegesture的各個方向?

- (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;}}

展開圖片的時候怎麼才能讓圖片不變形？

1. UIImage *image = [[UIImage imageNamed:@"xxx"] stretchableImageWithLeftCapWidth:10 topCapHeight:10];
   (剛才有人提醒這個已經deprecated了哈,現在的方法叫resizableImageWithCapInsets).

2. 
    

怎麼播放GIF的時候這麼卡，有沒有好點的庫？

FlipBoard出品的太適合你了。https://github.com/Flipboard/FLAnimatedImage

怎麼一句話添加上拉重新整理？

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:SVPullToRefreshPositionBottom];

怎麼把tableview裡cell的小對勾的顏色改成別的顏色？

_mTableView.tintColor = [UIColor redColor];

 本來我的statusbar是lightcontent的，結果用UIImagePickerController會導致我的statusbar的樣式變成黑色，怎麼辦？

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

怎麼把我的navigationbar弄成透明的而不是帶模糊的效果？

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

怎麼改變uitextfield placeholder的顏色和位置？

繼承uitextfield，重寫這個方法
- (void) drawPlaceholderInRect:(CGRect)rect { [[UIColor blueColor] setFill]; [self.placeholder drawInRect:rect withFont:self.font lineBreakMode:UILineBreakModeTailTruncation alignment:self.textAlignment];

文／葉孤城___（簡書作者）
原文連結：http://www.jianshu.com/p/08f194e9904c
著作權歸作者所有，轉載請聯絡作者獲得授權，並標註“簡書作者”。

iOS開發的小技巧