• iOS开发的一些奇巧淫技


    本文转载至 http://www.cocoachina.com/ios/20141231/10783.html

    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.

    01.png

    很简单.

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    self.tableView.tableFooterView = [[UIView alloc] init];

    试过的都说好.

    加完这句之后就变成了这样.

    02.png

    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;

    ScrollView莫名其妙不能在viewController划到顶怎么办?

    1
    self.automaticallyAdjustsScrollViewInsets = NO;

    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.

    为什么我的app老是不流畅,到底哪里出了问题?

    如图

    03.gif

    这个神器叫做:KMCGeigerCounter,快去github搬运吧.

    怎么在不新建一个Cell的情况下调整separaLine的位置?

    1
    _myTableView.separatorInset = UIEdgeInsetsMake(0, 100, 0, 0);

    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];
    }

    怎么给每个ViewController设定默认的背景图片?

    使用基类啊,少年。

    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.

    怎么像safari一样滑动的时候隐藏navigationbar?

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    navigationController.hidesBarsOnSwipe = Yes

    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];

    CoreData用起来好烦,语法又臭又长,怎么办?

    MagicRecord

    CollectionView 怎么实现tableview那种悬停的header?

    CSStickyHeaderFlowLayou

    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;
    }
    }

    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.

    05.gif


    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

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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];

    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];

    04.png

    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];
    }

    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;

    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];
    }

    你为什么知道这么多奇怪的花招?

    去stackoverflow刷问题啊,少年!

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  • 原文地址:https://www.cnblogs.com/Camier-myNiuer/p/4378533.html
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