iOS 开发技巧

一.UITabelView

1.去掉多余的cell

_tableView.tableFooterView = [[UIView alloc] init];

2.tableview或者scrollview不能再VC中滑到顶

self.automaticallyAdjustsScrollViewInsets = NO;

3.tableview加个默认隐藏的搜索框

self.tableView.tableHeaderView=self.searchDisplayController.searchBar;

self.tableView.contentOffset=CGPointMake(0,CGRectGetHeight(self.searchDisplayController.searchBar.bounds));

4.全屏显示tableview的分割线

cell.layoutMargins=UIEdgeInsetsZero;

_mineTableView.separatorInset=UIEdgeInsetsZero;

_mineTableView.layoutMargins=UIEdgeInsetsZero;

5.修改cell被选中的颜色

cell.selectedBackgroundView.backgroundColor= [UIColorredColor];

cell.accessoryType=UITableViewCellAccessoryDisclosureIndicator;

二.导航栏、VC

1.滑动隐藏导航栏

self.automaticallyAdjustsScrollViewInsets = NO;

2.导航栏返回键带的title不好看，换掉

[[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(NSIntegerMin, NSIntegerMin) forBarMetrics:UIBarMetricsDefault];

3.把navigationBar变成透明

[self.navigationController.navigationBar setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault];

self.navigationController.navigationBar.translucent = YES;

4.去掉navigationBar下面的黑色细线

[self.navigationController.navigationBar setBackgroundImage:[[UIImage alloc] init] forBarMetrics:UIBarMetricsDefault];

self.navigationController.navigationBar.shadowImage = [UIImage new];

5.去掉tabBar下面的黑色细线

[self.tabBarController.tabBar setBackgroundImage:[UIImage new]];

[self.tabBarController.tabBar setShadowImage:[UIImage new]];

6.导航栏遮住了Y为0 的控件

（1）

self.edgesForExtendedLayout = UIRectEdgeNone;

（2）

self.navigationController.navigationBar.translucent = NO;

3.UIbutton

1.文字左侧显示

button.contentHorizontalAlignment=UIControlContentHorizontalAlignmentLeft;

button.contentEdgeInsets=UIEdgeInsetsZero;

4.收起键盘（最好在基类）

- (void)touchesBegan:(NSSet*)touches withEvent:(UIEvent *)event

{

[self.view endEditing:YES];

[[UIApplication sharedApplication] sendAction:@selector(resignFirstResponder) to:nil from:nil forEvent:nil];

[[[UIApplication sharedApplication] keyWindow] endEditing:YES];

}

5.截屏

- (void)screenShot

{

UIViewController *vc = [WPMethodManager getFrontViewController];

CGSize size = vc.view.frame.size;

// 开启上下文,使用参数之后,截出来的是原图（YES  0.0 质量高）

UIGraphicsBeginImageContextWithOptions(size, YES, 0);

// 裁剪的关键代码,要裁剪的矩形范围

CGRect rect = CGRectMake(0, -20, size.width, size.height + 20);

//注：iOS7以后renderInContext：由drawViewHierarchyInRect：afterScreenUpdates：替代

[vc.view drawViewHierarchyInRect:rect afterScreenUpdates:YES];

// 从上下文中,取出UIImage

UIImage *shotImage = UIGraphicsGetImageFromCurrentImageContext();

//保存

UIImageWriteToSavedPhotosAlbum(shotImage, nil, nil, nil);

//结束上下文(移除栈顶上下文)

UIGraphicsEndImageContext();

}

三.Tabbar

1.pop返回指定的tabbar selectedIndex

AYTabBarController *tabBar = (AYTabBarController *)kkeyWindow.rootViewController;

[self.navigationController popToRootViewControllerAnimated:YES];

tabBar.tabBar.hidden = NO;

dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{

tabBar.selectedIndex = 1;

});

   注意：tabbarC如果是自定义的就拿到自定义的tabbarC

四.UITextField、UITextView

1.文字内容偏移

    1.UITextField

_circleNameTextField.leftView = [[UIView alloc] initWithFrame:kCGRect(0, 0, 10, _circleNameTextField.jk_height)];

_circleNameTextField.leftViewMode = UITextFieldViewModeAlways;

    2.UITextView

_detailTextView.textContainerInset = UIEdgeInsetsMake(10, 10, 0, 0);