iOS 开发一些小技巧(收集整理)

来源：互联网发布：淘宝被扣24分还能用吗编辑：程序博客网时间：2024/05/22 15:08

去除UITableView多余的Cell

self.tableView.tableFooterView = [UIView new];

自定义了leftBarbuttonItem左滑返回手势失效了怎么办?

    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?

self.automaticallyAdjustsScrollViewInsets = NO;

怎么在不新建一个Cell的情况下调整separaLine的位置?

self.tableView.separatorInset = UIEdgeInsetsMake(0, 50, 0, 0);

在iOS8中无效
iOS8中使用
以下示范为separaLine的位置为0的情况

1:在ViewDidLoad 或者tabbleView 的getter 方法中加入下面代码if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0) {    if ([_tableView respondsToSelector:@selector(setSeparatorInset:)]) {        [_tableView setSeparatorInset:UIEdgeInsetsZero];    }    if ([_tableView respondsToSelector:@selector(setLayoutMargins:)]) {        [_tableView setLayoutMargins:UIEdgeInsetsZero];    }}2:在UITableViewDelegate- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath{   if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0) {        if ([cell respondsToSelector:@selector(setSeparatorInset:)]) {            [cell setSeparatorInset:UIEdgeInsetsZero];        }        if ([cell respondsToSelector:@selector(setLayoutMargins:)]) {            [cell setLayoutMargins:UIEdgeInsetsZero];        }    }}

怎么点击self.view就让键盘收起,需要添加一个tapGestures么?

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {        [self.view endEditing:YES];}

怎么像safari一样滑动的时候隐藏navigationbar?

     self.navigationController.hidesBarsOnSwipe = Yes;

查看View的层次结构

    [view recursiveDescription];

导航条返回键带的title太讨厌了,怎么让它消失!

此方法写在APPDelegate 中整个工程都适用

[[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60)                       forBarMetrics:UIBarMetricsDefault];

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];}

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;}

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