一些简单的小技巧

时间:2021-10-24 16:04:12

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];
  2. 一些简单的小技巧

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];

一些简单的小技巧

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!