ios中常用小技巧注意点

1.设置图片原图显示

 UIImage*image=[UIImage imageNamed:@"place_map.png"];
UIImage*original=[image imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
self.navigationItem.rightBarButtonItem=[[UIBarButtonItem alloc]initWithImage:original style:UIBarButtonItemStylePlain target:self action:@selector(locationPress)];

2.修改全局barButton渲染颜色 和字体样式

 UINavigationBar *navgationBar = [UINavigationBar appearance];
navgationBar.tintColor = [UIColor colorWithRed:0.61f green:0.61f blue:0.61f alpha:1.00f];
  [[UINavigationBar appearance] setTitleTextAttributes:@{NSFontAttributeName:[UIFont boldSystemFontOfSize:15],NSForegroundColorAttributeName:UIColorWithHexRGB(0xfe6d27)}];

 [[UITabBarItem appearance] setTitleTextAttributes:@{NSFontAttributeName : [UIFont boldSystemFontOfSize:10],NSForegroundColorAttributeName : kRGBCOLOR(170,170,170)} forState:UIControlStateNormal]

3.隐藏tabbar

-(void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated {
viewController.hidesBottomBarWhenPushed = YES;
[super pushViewController:viewController animated:animated];

if (self.childViewControllers.count==1) {

    viewController.hidesBottomBarWhenPushed = NO;

}
}

4、TableView的Group样式中,默认的每个section都有sectionHeader和sectionFooter,只要调整这两个的大小就可以实现section之前的间距扩大或缩小

//tableview自带35距离
self.tableView.contentInset = UIEdgeInsetsMake(-35,0,0,0);

5.获取label大小

textLabel.size = [textLabel.text boundingRectWithSize:CGSizeMake(CGFLOAT_MAX, textLabel.font.lineHeight)
                                              options:NSStringDrawingUsesLineFragmentOrigin
                                           attributes:@{NSFontAttributeName : textLabel.font}
                                              context:nil].size;

6、tableviewcell让分割线从头开始

-(void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath  
{  
if ([cell respondsToSelector:@selector(setSeparatorInset:)]) {  
    [cell setSeparatorInset:UIEdgeInsetsZero];  
}  

if ([cell respondsToSelector:@selector(setLayoutMargins:)]) {  
    [cell setLayoutMargins:UIEdgeInsetsZero];  
}  
}