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？

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

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*刷问题啊，少年！

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一些简单的小技巧