iOS 常用方法

1.根据字体大小的计算出字符串的长和宽

  CGSize nameSize = [name sizeWithAttributes:[NSDictionary dictionaryWithObjectsAndKeys:[UIFont systemFontOfSize:14],NSFontAttributeName, nil]];

2.通过生日计算年龄

//  calculate age by birthday//  birthday : YYYYMMDD//  age: *岁*个月*天- (NSString *)ageStringByBirthday:(NSString *)birthday{    //年齢計算    NSDateFormatter *inputFormatter = [[NSDateFormatter alloc] init];    [inputFormatter setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"zh_CN"] ] ;    [inputFormatter setDateFormat:@"yyyyMMdd"];    NSDate* inputDate = [inputFormatter dateFromString:birthday];    NSDate *today = [NSDate date];    NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];    NSDateComponents *dayComponents = [gregorian components:NSCalendarUnitYear | NSCalendarUnitMonth| NSCalendarUnitDay fromDate:inputDate toDate:today options:0];    long year = [dayComponents year];    long month = [dayComponents month];    long day = [dayComponents day];    NSString *result = [NSString stringWithFormat:@"%li岁%li个月%li天",year,month,day];    return result;}

3.为右边的导航按钮设置弹簧距离

UIButton* rightBtn= [UIButton buttonWithType:UIButtonTypeCustom];    rightBtn.titleLabel.font = [UIFont systemFontOfSize:11];    [rightBtn setTitleColor:[UIColor colorWithRed:255.0/255 green:93.0/255 blue:93.0/255 alpha:1] forState:(UIControlStateNormal)];    rightBtn.frame = CGRectMake(self.view.bounds.size.width-70, 20, 60, 44);    UIBarButtonItem* rightBtnItem = [[UIBarButtonItem alloc]initWithCustomView:rightBtn];    [rightBtn addTarget:self action:@selector(attentionBtnClick:) forControlEvents:UIControlEventTouchUpInside];    UIBarButtonItem *spaceItem = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:(UIBarButtonSystemItemFixedSpace) target:nil action:nil];    spaceItem.width = -12;    self.navigationItem.rightBarButtonItems = @[spaceItem, rightBtnItem];

4.使得tableview在界面启动后定位在某一行

NSIndexPath *idxPath = [NSIndexPath indexPathForRow:5 inSection:0];   [self.tableView scrollToRowAtIndexPath:idxPath  atScrollPosition:UITableViewScrollPositionMiddle  animated:NO]；

5.给定宽度和字体大小计算字符串的高度

- (CGSize)getHeightText:(NSString*)text{    NSDictionary *attribute = @{NSFontAttributeName: [UIFont systemFontOfSize:14]};    CGSize size = [text boundingRectWithSize:CGSizeMake(kWindowW-COMMON_CARD_MARGIN*2-105, MAXFLOAT) options: NSStringDrawingTruncatesLastVisibleLine | NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading attributes:attribute context:nil].size;    return size;}

6.检测是否是手机号码

-(BOOL)isMobileNumber:(NSString*)mobileNum{//手机号码//移动：134[0-8],135,136,137,138,139,150,151,157,158,159,182,187,188//联通：130,131,132,152,155,156,185,186//电信：133,1349,153,180,189NSString*MOBILE=@"^1(3[0-9]|5[0-35-9]|8[025-9])\\d{8}$"; //中国移动：China MobileNSString*CM=@"^1(34[0-8]|(3[5-9]|5[017-9]|8[278])\\d)\\d{7}$";    // 中国联通：China UnicomNSString*CU=@"^1(3[0-2]|5[256]|8[56])\\d{8}$";    // 中国电信：China TelecomNSString*CT=@"^1((33|53|8[09])[0-9]|349)\\d{7}$";  // 大陆地区固话及小灵通// NSString * PHS = @"^0(10|2[0-5789]|\\d{3})\\d{7,8}$";    NSPredicate*regextestmobile=[NSPredicate predicateWithFormat:@"SELF MATCHES %@",MOBILE];    NSPredicate*regextestcm=[NSPredicate predicateWithFormat:@"SELF MATCHES %@",CM];    NSPredicate*regextestcu=[NSPredicate predicateWithFormat:@"SELF MATCHES %@",CU];    NSPredicate*regextestct=[NSPredicate predicateWithFormat:@"SELF MATCHES %@",CT];    if(([regextestmobile evaluateWithObject:mobileNum]==YES)||([regextestcm evaluateWithObject:mobileNum]==YES)||([regextestct evaluateWithObject:mobileNum]==YES)||([regextestcu evaluateWithObject:mobileNum]==YES)){    return YES;        }else{    return NO;    }}

7.怎么画虚线

- (instancetype)initWithFrame:(CGRect)frame{    if (self = [super initWithFrame:frame]) {        [self drawRect:frame];    }    return self;}-(void)drawRect:(CGRect)rect{    //    self.layer.cornerRadius = 10;    UIView *lineView = [[UIView alloc]init];    lineView.frame = CGRectMake(12, rect.size.height-1,rect.size.width-12*2, 1);    [DashedLineView drawDashLine:lineView lineLength:4 lineSpacing:3                 lineColor:kRTColorWithHEX(0xd0d0d0, 1.0)];    [self addSubview:lineView];}/** ** lineView:       需要绘制成虚线的view ** lineLength:     虚线的宽度 ** lineSpacing:    虚线的间距 ** lineColor:      虚线的颜色 **/+ (void)drawDashLine:(UIView *)lineView lineLength:(int)lineLength lineSpacing:(int)lineSpacing lineColor:(UIColor *)lineColor{    CAShapeLayer *shapeLayer = [CAShapeLayer layer];    [shapeLayer setBounds:lineView.bounds];    [shapeLayer setPosition:CGPointMake(CGRectGetWidth(lineView.frame) / 2, CGRectGetHeight(lineView.frame))];    [shapeLayer setFillColor:[UIColor clearColor].CGColor];    //  设置虚线颜色为blackColor    [shapeLayer setStrokeColor:lineColor.CGColor];    //  设置虚线宽度    [shapeLayer setLineWidth:CGRectGetHeight(lineView.frame)];    [shapeLayer setLineJoin:kCALineJoinRound];    //  设置线宽，线间距    [shapeLayer setLineDashPattern:[NSArray arrayWithObjects:[NSNumber numberWithInt:lineLength], [NSNumber numberWithInt:lineSpacing], nil]];    //  设置路径    CGMutablePathRef path = CGPathCreateMutable();    CGPathMoveToPoint(path, NULL, 0, 0);    CGPathAddLineToPoint(path, NULL, CGRectGetWidth(lineView.frame), 0);    [shapeLayer setPath:path];    CGPathRelease(path);    //  把绘制好的虚线添加上来    [lineView.layer addSublayer:shapeLayer];}

8.把图片保存到相册中

- (void)save:(UIBarButtonItem *)sender {    UIGraphicsBeginImageContext(self.hmView.bounds.size);    CGContextRef ctx = UIGraphicsGetCurrentContext();    [self.hmView.layer renderInContext:ctx];    UIImage * image = UIGraphicsGetImageFromCurrentImageContext();    UIGraphicsEndImageContext();    UIImageWriteToSavedPhotosAlbum(image, NULL, NULL, NULL);}

9.创建单一颜色的图片然后设置UIControlStateHighlighted状态

+ (UIImage *)imageWithColor:(UIColor *)color size:(CGSize)size {    CGRect rect = CGRectMake(0, 0, size.width, size.height);    UIGraphicsBeginImageContext(rect.size);    CGContextRef context = UIGraphicsGetCurrentContext();    CGContextSetFillColorWithColor(context, [color CGColor]);     CGContextFillRect(context, rect);    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();    UIGraphicsEndImageContext();    return image;}

10.UIView中的坐标转换

// 将像素point由point所在视图转换到目标视图view中，返回在目标视图view中的像素值      - (CGPoint)convertPoint:(CGPoint)point toView:(UIView *)view;      // 将像素point从view中转换到当前视图中，返回在当前视图中的像素值      - (CGPoint)convertPoint:(CGPoint)point fromView:(UIView *)view;      // 将rect由rect所在视图转换到目标视图view中，返回在目标视图view中的rect      - (CGRect)convertRect:(CGRect)rect toView:(UIView *)view;      // 将rect从view中转换到当前视图中，返回在当前视图中的rect      - (CGRect)convertRect:(CGRect)rect fromView:(UIView *)view;      // controllerA 中有一个UITableView, UITableView里有多行UITableVieCell，cell上放有一个button      // 在controllerA中实现:      CGRect rc = [cell convertRect:cell.btn.frame toView:self.view];      或      CGRect rc = [self.view convertRect:cell.btn.frame fromView:cell];      // 此rc为btn在controllerA中的rect      或当已知btn时：      CGRect rc = [btn.superview convertRect:btn.frame toView:self.view];      或      CGRect rc = [self.view convertRect:btn.frame fromView:btn.superview];

11.颜色：rgb，和16进制

#define kRTColorWihRGB(R,G,B)     [UIColor colorWithRed:R/255.0 green:G/255.0 blue:B/255.0 alpha:1.0]#define kRTColorWithHEX(hex,opa)  [UIColor colorWithRed:((float)((hex & 0XFF0000)>>16))/255.0 green:((float)((hex & 0X00FF00)>>8))/255.0 blue:((float)(hex & 0X0000FF))/255.0 alpha:opa]

12.把数据变成三位加逗号的数据类型

- (NSString *)formatNumber:(double)num{    NSNumberFormatter *formatterCurrency = [[NSNumberFormatter alloc] init];    formatterCurrency.numberStyle = NSNumberFormatterDecimalStyle;    [formatterCurrency setMaximumFractionDigits:2];    return [formatterCurrency stringFromNumber: @(num)];}

13. 把科学计数法变为普通数

{NSString *str = @"1.2808245E7";    NSRange eSite = [str rangeOfString:@"E"];    double fund = [[str substringWithRange:NSMakeRange(0, eSite.location)] doubleValue];  //把E前面的数截取下来当底数    double top = [[str substringFromIndex:eSite.location + 1] doubleValue];   //把E后面的数截取下来当指数    double result = fund * pow(10.0, top);}

14.一些判断的方法

-(BOOL) isKindOfClass: classObj 用来判断是否是某个类或其子类的实例-(BOOL) isMemberOfClass: classObj 用来判断是否是某个类的实例-(BOOL) respondsToSelector: selector 用来判断是否有以某个名字命名的方法(被封装在一个selector的对象里传递)+(BOOL) instancesRespondToSelector: selector 用来判断实例是否有以某个名字命名的方法. 和上面一个不同之处在于, 前面这个方法可以用在实例和类上，而此方法只能用在类上.

15.UIDatePicker的简单使用

UIDatePicker *dp = [[UIDatePicker alloc] init];     [dp setDate:[NSDate date] animated:YES];    // 设置日期控件值     [dp addTarget:self            action:@selector(dateValueChange:)  forControlEvents:UIControlEventValueChanged];  // 时间改变时触发此事件     设置日期选择控件的地区[dp setLocale:[[NSLocale alloc]initWithLocaleIdentifier:@"zh_CN"]];     NSDateFormatter *form = [[NSDateFormatter alloc] init]; // 定义时间       格式     [form setDateFormat:@"yyyy/MM/DD HH:mm"];     NSString *dateString = [form stringFromDate:dp.date];     dp.minuteInterval = 30; //  最小间隔30分钟     dp.minimumDate = [NSDate date];     // 最小值     dp.maximumDate = [NSDate dateWithTimeIntervalSinceNow:60*60*24*31]; // 最大值     dp.datePickerMode = UIDatePickerModeTime;               // 时间模式     dp.datePickerMode = UIDatePickerModeDate;               // 日期模式     dp.datePickerMode = UIDatePickerModeDateAndTime;        // 日期和时  间模式  dp.datePickerMode = UIDatePickerModeCountDownTimer;     // 倒计时模式

创建block匿名函数之前一般需要对self进行weak化，否则造成循环引用无法释放controller:

 __weak MyController *weakSelf = self 或者 __weak __typeof(self) weakSelf = self;