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：133,1349,153,180,189
NSString*MOBILE=@"^1(3[0-9]|5[0-35-9]|8[025-9])\\d{8}$";

 //中国移动：China Mobile
NSString*CM=@"^1(34[0-8]|(3[5-9]|5[017-9]|8[278])\\d)\\d{7}$";


    // 中国联通：China Unicom
NSString*CU=@"^1(3[0-2]|5[256]|8[56])\\d{8}$";

    // 中国电信：China Telecom
NSString*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;