【解决方法】iOS 开发小技巧(二)
1、TableView不显示没内容的Cell怎么办?
类似这种,我不想让下面那些空的显示.
很简单.
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self.tableView.tableFooterView = [[UIView alloc] init];
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试过的都说好.
加完这句之后就变成了这样.
2、自定义了leftBarbuttonItem左滑返回手势失效了怎么办?
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self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc]
initWithImage:img
style:UIBarButtonItemStylePlain
target:self
action:@selector(onBack:)];
self.navigationController.interactivePopGestureRecognizer.delegate = (id)self;
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ScrollView莫名其妙不能在viewController划到顶怎么办?
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self.automaticallyAdjustsScrollViewInsets = NO;
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3、键盘事件写的好烦躁,都想摔键盘了,怎么办?
1.买个结实的键盘.
2.使用IQKeyboardManager(github上可搜索),用完之后腰也不疼了,腿也不酸了.
4、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搬运吧.
5、怎么在不新建一个Cell的情况下调整separaLine的位置?
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_myTableView.separatorInset = UIEdgeInsetsMake(0, 100, 0, 0);
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6、怎么点击self.view就让键盘收起,需要添加一个tapGestures么?
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- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[self.view endEditing:YES];
}
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7、怎么给每个ViewController设定默认的背景图片?
使用基类啊,少年。
8、想在代码里改在xib里添加的layoutAttributes,但是怎么用代码找啊?
像拉button一样的拉你的约束.nslayoutattribute也是可以拉线的.
9、怎么像safari一样滑动的时候隐藏navigationbar?
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navigationController.hidesBarsOnSwipe = Yes
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10、导航条返回键带的title太讨厌了,怎么让它消失!
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[[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60)
forBarMetrics:UIBarMetricsDefault];
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11、CoreData用起来好烦,语法又臭又长,怎么办?
MagicRecord
12、CollectionView 怎么实现tableview那种悬停的header?
CSStickyHeaderFlowLayou
13、能不能只用一个pan手势来代替UISwipegesture的各个方向?
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- (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
;
}
}
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14、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.
15、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
16、怎么一句话添加上拉刷新？
https://github.com/samvermette/SVPullToRefresh
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[tableView addPullToRefreshWithActionHandler:^{
// prepend data to dataSource, insert cells at top of table view
// call [tableView.pullToRefreshView stopAnimating] when done
} position:SVPullToRefreshPositionBottom];
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17、怎么把tableview里cell的小对勾的颜色改成别的颜色？
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_mTableView.tintColor = [UIColor redColor];
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18、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？
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- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];
}
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19、怎么把我的navigationbar弄成透明的而不是带模糊的效果？
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[self.navigationBar setBackgroundImage:[UIImage
new
]
forBarMetrics:UIBarMetricsDefault];
self.navigationBar.shadowImage = [UIImage
new
];
self.navigationBar.translucent = YES;
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20、怎么改变uitextfield placeholder的颜色和位置？
继承uitextfield，重写这个方法
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- (void) drawPlaceholderInRect:(CGRect)rect {
[[UIColor blueColor] setFill];
[self.placeholder drawInRect:rect withFont:self.font lineBreakMode:UILineBreakModeTailTruncation alignment:self.textAlignment];
}
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