- 打印View所有子视图
po [[self view]recursiveDescription] - layoutSubviews调用的调用时机* 当视图第一次显示的时候会被调用* 当这个视图显示到屏幕上了,点击按钮* 添加子视图也会调用这个方法* 当本视图的大小发生改变的时候是会调用的* 当子视图的frame发生改变的时候是会调用的* 当删除子视图的时候是会调用的
- NSString过滤特殊字符
// 定义一个特殊字符的集合
NSCharacterSet *set = [NSCharacterSet characterSetWithCharactersInString:@"@／：；（）¥「」＂、[]{}#%-*+=_\\|~＜＞$€^•'@#$%^&*()_+'\""];// 过滤字符串的特殊字符NSString *newString = [trimString stringByTrimmingCharactersInSet:set];
- TransForm属性
//平移按钮
CGAffineTransform transForm = self.buttonView.transform;self.buttonView.transform = CGAffineTransformTranslate(transForm, 10, 0);
//旋转按钮
CGAffineTransform transForm = self.buttonView.transform;self.buttonView.transform = CGAffineTransformRotate(transForm, M_PI_4);
//缩放按钮
self.buttonView.transform = CGAffineTransformScale(transForm, 1.2, 1.2);//初始化复位self.buttonView.transform = CGAffineTransformIdentity;
- 去掉分割线多余15像素首先在viewDidLoad方法加入以下代码：
if ([self.tableView respondsToSelector:@selector(setSeparatorInset:)]) { [self.tableView setSeparatorInset:UIEdgeInsetsZero]; }
if ([self.tableView respondsToSelector:@selector(setLayoutMargins:)]) { [self.tableView setLayoutMargins:UIEdgeInsetsZero];}
- 计算方法耗时时间间隔
// 获取时间间隔#define TICK CFAbsoluteTime start = CFAbsoluteTimeGetCurrent();#define TOCK NSLog(@"Time: %f", CFAbsoluteTimeGetCurrent() - start)
- Color颜色宏定义
// 随机颜色
#define RANDOM_COLOR [UIColor colorWithRed:arc4random_uniform(256) / 255.0 green:arc4random_uniform(256) / 255.0 blue:arc4random_uniform(256) / 255.0 alpha:1]// 颜色(RGB)#define RGBCOLOR(r, g, b) [UIColor colorWithRed:(r)/255.0f green:(g)/255.0f blue:(b)/255.0f alpha:1]#define RGBACOLOR(r, g, b, a) [UIColor colorWithRed:(r)/255.0f green:(g)/255.0f blue:(b)/255.0f alpha:(a)]
- Alert提示宏定义
#define Alert(_S_, ...) [[[UIAlertView alloc] initWithTitle:@"提示" message:[NSString stringWithFormat:(_S_), ##__VA_ARGS__] delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil] show]8，让 iOS 应用直接退出- (void)exitApplication { AppDelegate *app = [UIApplication sharedApplication].delegate; UIWindow *window = app.window; [UIView animateWithDuration:1.0f animations:^{ window.alpha = 0; } completion:^(BOOL finished) { exit(0); }];}
- NSArray 快速求总和 最大值 最小值 和 平均值
NSArray *array = [NSArray arrayWithObjects:@"2.0", @"2.3", @"3.0", @"4.0", @"10", nil];
CGFloat sum = [[array valueForKeyPath:@"@sum.floatValue"] floatValue];CGFloat avg = [[array valueForKeyPath:@"@avg.floatValue"] floatValue];
CGFloat max =[[array valueForKeyPath:@"@max.floatValue"] floatValue];
CGFloat min =[[array valueForKeyPath:@"@min.floatValue"] floatValue];NSLog(@"%f\n%f\n%f\n%f",sum,avg,max,min);
检测是否IPad Pro
- (BOOL)isIpadPro
{
UIScreen *Screen = [UIScreen mainScreen];
CGFloat width = Screen.nativeBounds.size.width/Screen.nativeScale;
CGFloat height = Screen.nativeBounds.size.height/Screen.nativeScale;
BOOL isIpad =[[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad;
BOOL hasIPadProWidth = fabs(width - 1024.f) < DBL_EPSILON;
BOOL hasIPadProHeight = fabs(height - 1366.f) < DBL_EPSILON;
return isIpad && hasIPadProHeight && hasIPadProWidth;
}
修改Tabbar Item的属性
// 修改标题位置
self.tabBarItem.titlePositionAdjustment = UIOffsetMake(0, -10);
// 修改图片位置
self.tabBarItem.imageInsets = UIEdgeInsetsMake(-3, 0, 3, 0);
// 批量修改属性
for (UIBarItem *item in self.tabBarController.tabBar.items) {
[item setTitleTextAttributes:[NSDictionary dictionaryWithObjectsAndKeys:
[UIFont fontWithName:@"Helvetica" size:19.0], NSFontAttributeName, nil]
forState:UIControlStateNormal];
}
// 设置选中和未选中字体颜色
[[UITabBar appearance] setShadowImage:[[UIImage alloc] init]];
//未选中字体颜色
[[UITabBarItem appearance] setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor greenColor]} forState:UIControlStateNormal];
//选中字体颜色
[[UITabBarItem appearance] setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor cyanColor]} forState:UIControlStateSelected];
NULL - nil - Nil - NSNULL的区别
-
nil是OC的，空对象，地址指向空（0）的对象。对象的字面零值
-
Nil是Objective-C类的字面零值
-
NULL是C的，空地址，地址的数值是0，是个长整数
-
NSNull用于解决向NSArray和NSDictionary等集合中添加空值的问题
去掉BackBarButtonItem的文字
[[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60)
forBarMetrics:UIBarMetricsDefault];
控件不能交互的一些原因
-
控件的userInteractionEnabled = NO
-
透明度小于等于0.01，aplpha
-
控件被隐藏的时候，hidden = YES
-
子视图的位置超出了父视图的有效范围，子视图无法交互，设置了
修改UITextField中Placeholder的文字颜色
[text setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];
视图的生命周期
-
alloc 创建对象，分配空间
-
init (initWithNibName) 初始化对象，初始化数据
-
loadView 从nib载入视图 ，除非你没有使用xib文件创建视图
-
viewDidLoad 载入完成，可以进行自定义数据以及动态创建其他控件
-
viewWillAppear视图将出现在屏幕之前，马上这个视图就会被展现在屏幕上了
-
viewDidAppear 视图已在屏幕上渲染完成
-
viewWillDisappear 视图将被从屏幕上移除之前执行
-
viewDidDisappear 视图已经被从屏幕上移除，用户看不到这个视图了
-
dealloc 视图被销毁，此处需要对你在init和viewDidLoad中创建的对象进行释放.
-
viewVillUnload－ 当内存过低，即将释放时调用；
-
viewDidUnload－当内存过低，释放一些不需要的视图时调用。
判断view是不是指定视图的子视图
BOOL isView = [textView isDescendantOfView:self.view];
页面强制横屏
//pragma mark - 强制横屏代码
- (BOOL)shouldAutorotate{
//是否支持转屏
return NO;
}
- (UIInterfaceOrientationMask)supportedInterfaceOrientations{
//支持哪些转屏方向
return UIInterfaceOrientationMaskLandscape;
}
- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation{
return UIInterfaceOrientationLandscapeRight;
}
- (BOOL)prefersStatusBarHidden{
return NO;
}
系统键盘通知消息
-
UIKeyboardWillShowNotification-将要弹出键盘
-
UIKeyboardDidShowNotification-显示键盘
-
UIKeyboardWillHideNotification-将要隐藏键盘
-
UIKeyboardDidHideNotification-键盘已经隐藏
-
UIKeyboardWillChangeFrameNotification-键盘将要改变frame
-
UIKeyboardDidChangeFrameNotification-键盘已经改变frame
关闭navigationController的滑动返回手势
self.navigationController.interactivePopGestureRecognizer.enabled = NO;
设置状态栏为任意的颜色
- (void)setStatusColor
{
UIView *statusBarView = [[UIView alloc] initWithFrame:CGRectMake(0, 0,[UIScreen mainScreen].bounds.size.width, 20)];
statusBarView.backgroundColor = [UIColor orangeColor];
[self.view addSubview:statusBarView];
}
让Xcode的控制台支持LLDB类型的打印
打开终端输入三条命令:
touch ~/.lldbinit
echo display @import UIKit >> ~/.lldbinit
echo target stop-hook add -o \"target stop-hook disable\" >> ~/.lldbinit
下次重新运行项目，然后就不报错了。
Label行间距
-（void）test{
NSMutableAttributedString *attributedString =
[[NSMutableAttributedString alloc] initWithString:self.contentLabel.text];
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
[paragraphStyle setLineSpacing:3];
//调整行间距
[attributedString addAttribute:NSParagraphStyleAttributeName
value:paragraphStyle
range:NSMakeRange(0, [self.contentLabel.text length])];
self.contentLabel.attributedText = attributedString;
}
UIImageView填充模式
@"UIViewContentModeScaleToFill", // 拉伸自适应填满整个视图
@"UIViewContentModeScaleAspectFit", // 自适应比例大小显示
@"UIViewContentModeScaleAspectFill", // 原始大小显示
@"UIViewContentModeRedraw", // 尺寸改变时重绘
@"UIViewContentModeCenter", // 中间
@"UIViewContentModeTop", // 顶部
@"UIViewContentModeBottom", // 底部
@"UIViewContentModeLeft", // 中间贴左
@"UIViewContentModeRight", // 中间贴右
@"UIViewContentModeTopLeft", // 贴左上
@"UIViewContentModeTopRight", // 贴右上
@"UIViewContentModeBottomLeft", // 贴左下
@"UIViewContentModeBottomRight", // 贴右下
- 获取时间
//获取当地时间
- (NSString *)getCurrentTime {
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"yyyy-MM-dd"];
NSString *dateTime = [formatter stringFromDate:[NSDate date]];
return dateTime;
}
//将字符串转成NSDate类型
- (NSDate *)dateFromString:(NSString *)dateString {
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat: @"yyyy-MM-dd"];
NSDate *destDate= [dateFormatter dateFromString:dateString];
return destDate;
}
//传入今天的时间，返回明天的时间
- (NSString *)GetTomorrowDay:(NSDate *)aDate {
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
NSDateComponents *components = [gregorian components:NSCalendarUnitWeekday | NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay fromDate:aDate];
[components setDay:([components day]+1)];
NSDate *beginningOfWeek = [gregorian dateFromComponents:components];
NSDateFormatter *dateday = [[NSDateFormatter alloc] init];
[dateday setDateFormat:@"yyyy-MM-dd"];
return [dateday stringFromDate:beginningOfWeek];
}
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