如何旋转24小时制的时钟指针? [英] How to rotate the hands of clock for the 24 hour clock?

问题描述

我正在做一个时钟项目，我知道如何实现12小时制的指针(时，分，秒)旋转.我使用的代码如下

I am working on a clock project, i know how to implement hands (Hour, Minute, Seconds) rotation of 12 hour clock. The code i have used is follows

CGFloat secAngle,minAngle,hourAngle;

NSDateComponents *dateComponents = [[NSCalendar currentCalendar] components:(NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit) fromDate:[NSDate date]];
NSInteger seconds = [dateComponents second];
NSInteger minutes = [dateComponents minute];
NSInteger hours = [dateComponents hour];



if (timeFormat == 12)//12 hour clock
{

    if (hours > 12) hours -=12; //PM

     secAngle = Degrees2Radians(seconds/60.0*360);
     minAngle = Degrees2Radians(minutes/60.0*360);

     hourAngle = Degrees2Radians(hours/12.0*360) + minAngle/12.0;

    //secHand.transform = CATransform3DMakeRotation (secAngle+M_PI, 0, 0, 1);
    minHand.transform = CATransform3DMakeRotation (minAngle+M_PI, 0, 0, 1);
    hourHand.transform = CATransform3DMakeRotation (hourAngle+M_PI, 0, 0, 1);
}
else //24 hour clock
{

    secAngle = Degrees2Radians(seconds/60.0*360);
    minAngle = Degrees2Radians(minutes/60.0*360);
    hourAngle = (30 * hours + minutes / 2) /2;

    //secHand.transform = CATransform3DMakeRotation(secAngle * M_PI / 180,0,0,1);
    minHand.transform = CATransform3DMakeRotation(minAngle * M_PI ,0,0,1);
    hourHand.transform = CATransform3DMakeRotation(hourAngle * M_PI,0,0,1);


}

但是当我尝试实施24小时制时.它不起作用.每当我运行此项目时，时钟都会显示错误的时间.

But when i try to implement the 24 hour clock. It is not working. Each time when i run this project the clock shows wrong timings.

谁能告诉我我做错了什么.提前非常感谢

Can anyone tell me what wrong do i did. Many thanks in advance

推荐答案

这是我的工作方式-我使用脸部中心和角度来计算手部端点的x，y位置，从那里开始绘制很简单.这是完整的表盘类.它是UIView的子类.每秒设置它的时间属性，它就像一个魅力...

Here's how I do it - I use the face center and the angle to compute the x,y position of the endpoints of the hands, drawing is simple from there. Here's a complete clock face class. It's a subclass of UIView. Set it's time property every second and it works like a charm...

//
//  ClockFace.h
//

#import <UIKit/UIKit.h>

@interface ClockFace : UIView

@property (strong,nonatomic) NSDate *time;

@end


//  ClockFace.m

#import "ClockFace.h"

@interface ClockFace ()

@property(assign,nonatomic) CGPoint boundsCenter;
@property(assign,nonatomic) NSInteger seconds;
@property(assign,nonatomic) NSInteger minutes;
@property(assign,nonatomic) NSInteger hours;

@end

@implementation ClockFace

@synthesize time=_time;
@synthesize boundsCenter=_boundsCenter;

- (id)initWithCoder:(NSCoder *)aDecoder {

    self = [super initWithCoder:aDecoder];
    if (self) {
        _boundsCenter = CGPointMake(self.bounds.size.width/2.0, self.bounds.size.height/2.0);
    }
    return self;
}

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
        _boundsCenter = CGPointMake(self.bounds.size.width/2.0, self.bounds.size.height/2.0);
    }
    return self;
}

- (CGPoint)secondsHandPosition {

    float secondsAsRadians = (float)self.seconds / 60.0 * 2.0 * M_PI - M_PI_2;
    float handRadius = self.frame.size.width / 2.4;
    return CGPointMake(handRadius*cosf(secondsAsRadians)+self.boundsCenter.x, handRadius*sinf(secondsAsRadians)+self.boundsCenter.y);
}

- (CGPoint)minutesHandPosition {

    float minutesAsRadians = (float)self.minutes / 60.0 * 2.0 * M_PI - M_PI_2;
    float handRadius = self.frame.size.width / 2.2;
    return CGPointMake(handRadius*cosf(minutesAsRadians)+self.boundsCenter.x, handRadius*sinf(minutesAsRadians)+self.boundsCenter.y);
}

- (CGPoint)hoursHandPosition {

    float hoursAsRadians = (float)self.hours / 12.0 * 2.0 * M_PI - M_PI_2;
    float handRadius = self.frame.size.width / 3.8;
    return CGPointMake(handRadius*cosf(hoursAsRadians)+self.boundsCenter.x, handRadius*sinf(hoursAsRadians)+self.boundsCenter.y);
}


// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
    CGContextRef context = UIGraphicsGetCurrentContext();

    CGFloat zClear[4] = {1.0,1.0,1.0,0.0};
    CGContextSetFillColor(context, zClear); 
    CGContextFillRect(context, rect);

    CGRect face = CGRectInset(rect, 1.0, 1.0);
    CGContextSetLineWidth(context, 1.0);
    CGContextAddEllipseInRect(context, face);
    CGContextStrokePath(context);

    CGRect center = CGRectMake(self.boundsCenter.x-2.0, self.boundsCenter.y-2.0, 4.0, 4.0);
    CGContextAddEllipseInRect(context, center);
    CGContextStrokePath(context);

    CGFloat red[4] = {1.0f, 0.0f, 0.0f, 1.0f};
    CGPoint secondsHandPosition = [self secondsHandPosition];

    CGContextSetStrokeColor(context, red);
    CGContextBeginPath(context);
    CGContextMoveToPoint(context, self.boundsCenter.x, self.boundsCenter.y);
    CGContextAddLineToPoint(context, secondsHandPosition.x, secondsHandPosition.y);
    CGContextStrokePath(context);

    CGFloat black[4] = {0.0f, 0.0f, 0.0f, 1.0f};
    CGPoint minutesHandPosition = [self minutesHandPosition];

    CGContextSetStrokeColor(context, black);
    CGContextBeginPath(context);
    CGContextMoveToPoint(context, self.boundsCenter.x, self.boundsCenter.y);
    CGContextAddLineToPoint(context, minutesHandPosition.x, minutesHandPosition.y);
    CGContextStrokePath(context);

    CGPoint hoursHandPosition = [self hoursHandPosition];

    CGContextSetStrokeColor(context, black);
    CGContextBeginPath(context);
    CGContextMoveToPoint(context, self.boundsCenter.x, self.boundsCenter.y);
    CGContextAddLineToPoint(context, hoursHandPosition.x, hoursHandPosition.y);
    CGContextStrokePath(context);
}

- (void)setTime:(NSDate *)time {

    _time = time;

    static NSCalendar *gregorian;

    if (!gregorian) gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
    NSDateComponents *weekdayComponents =
    [gregorian components:(NSDayCalendarUnit | NSWeekdayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit) fromDate:time];

    self.hours = [weekdayComponents hour];
    if (self.hours > 12) self.hours -= 12;
    self.minutes = [weekdayComponents minute];
    self.seconds = [weekdayComponents second];

    [self setNeedsDisplay];
}


@end

要在视图控制器中使用此属性，请创建一个属性:

To use this in a view controller, create a property:

#import "ClockFace.h"

// ...

@property(strong, non atomic) ClockFace *clockFace;

确实加载了视图(或者如果您知道如何添加自定义视图，则在情节提要中):

In view did load (or in storyboard if you know how to add custom views):

self.clockFace = [[ClockFace alloc] initWithFrame:CGRectMake(10, 10, 300, 300)];

只要您希望时钟运行，请设置一个计时器:

Whenever you want the clock to run, setup a timer:

[NSTimer scheduledTimerWithTimeInterval:1.0
    target:self
    selector:@selector(timerFired:)
    userInfo:nil
    repeats:NO];

当计时器启动时，告诉时钟现在几点:

When the timer fires, tell the clock what time it is:

- (void)timerFired:(NSTimer *)timer {

    self.clockFace.time = [NSDate date];
}

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