iOS开发的一些奇巧淫技2

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) {    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];
   (刚才有人提醒这个已经deprecated了哈,现在的方法叫resizableImageWithCapInsets).

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

[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？

_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？

- (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？

[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
- (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！