设置时间单击拨号

Question

我正在制作一个警报应用程序，我必须在其中显示模拟时钟。功能是通过单击显示为时钟刻度盘的圆周来设置时间。

我也成功地做到了这一点。但问题出现在6点钟或30分钟。这个角度为nan，这使我的光滑时钟完全突然。

这是代码。

myPath1 = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(5, 5, 244, 244)];
    [myPath1 closePath];
    [myPath1 setLineWidth:20];

    // Draw a shape Layer with Triangle Path 
    CAShapeLayer *shapeLayer1 = [CAShapeLayer layer];
    shapeLayer1.fillColor   = [UIColor clearColor].CGColor;
    shapeLayer1.strokeColor = [UIColor clearColor].CGColor;
shapeLayer1.lineWidth   = 20;
shapeLayer1.path = myPath1.CGPath;

// Add it to your view
[circleView.layer addSublayer:shapeLayer1];


-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];

    CGPoint currentPoint = [touch locationInView:circleView];

    if([self containsPointOnStroke:currentPoint onPath:myPath1])
    {
        [self calculateAngle:currentPoint];
    }
}

- (BOOL)containsPointOnStroke:(CGPoint)point onPath:(UIBezierPath *)path
{
    CGPathRef cgPath = path.CGPath;
    CGPathRef strokedPath = CGPathCreateCopyByStrokingPath(cgPath, NULL, 10,
                                                           kCGLineCapRound, kCGLineJoinRound, 1);
    BOOL pointIsNearPath = CGPathContainsPoint(strokedPath, NULL, point, NO);
    CGPathRelease(strokedPath);

    return pointIsNearPath;
}

//---- calculate angle from the point of touch taking center as the reference ----//
- (void) calculateAngle : (CGPoint)currentPoint
{
    double distance = sqrt(pow((currentPoint.x - 127), 2.0) + pow((currentPoint.y - 5), 2.0));
    float val = ((2 * 14884) -  powf((distance), 2)) / (2 * 14884);
    float angleVal = acosf(val) * 180/M_PI;

    float timeval = angleVal;

    //NSLog(@"angleVal : %f timeVal : %.2f", angleVal, timeval);

    if (isnan(angleVal))
    {
        // if the value of the angle val is infinite
        if(check == 0)
            [hourBtn setTitle:@"06" forState:UIControlStateNormal];
        else
            [minBtn setTitle:@"30" forState:UIControlStateNormal];
    }
    else
    {
        if(check == 0)
        {
            if (currentPoint.x >= 127)
                [hourBtn setTitle:[self getHour:timeval reverseTIme:NO] forState:UIControlStateNormal];
            else
                [hourBtn setTitle:[self getHour:timeval reverseTIme:YES] forState:UIControlStateNormal];
        }
        else
        {
            if (currentPoint.x >= 127)
                [minBtn setTitle:[self getMin:timeval reverseTIme:NO] forState:UIControlStateNormal];
            else
                [minBtn setTitle:[self getMin:timeval reverseTIme:YES] forState:UIControlStateNormal];

        }
    }

    [timeLbl setText:[NSString stringWithFormat:@"%02d:%02d",[hourBtn.titleLabel.text intValue], [minBtn.titleLabel.text intValue]]];
}

//---- get the hour time from the angle ----//
- (NSString *) getHour :(float) angle reverseTIme:(BOOL) reverseCheck
{
    int minuteCount = angle * 2;
    int quo = minuteCount / 60;
    int temp = quo;
    if(quo == 0)
        quo = 12;

    NSString *timeStr = [NSString stringWithFormat:@"%02d",  quo];
    quo = temp;
    if (reverseCheck)
    {
        int revQuo = 11 - quo;
        if(revQuo == 0)
            revQuo = 12;
        timeStr = [NSString stringWithFormat:@"%02d", revQuo];
    }


    return timeStr;
}

// get the min time from the angle

- (NSString *) getMin :(float) angle reverseTIme:(BOOL) reverseCheck
{
    int minuteCount = angle;
    int rem = minuteCount / 6;


    NSString *timeStr = [NSString stringWithFormat:@"%02d", rem];
    if (reverseCheck)
    {
        int revRem = 60 - rem;
        if(revRem == 60)
            revRem = 0;

        timeStr = [NSString stringWithFormat:@"%02d", revRem];
    }

    //NSLog(@"timeStr : %@", timeStr);

    return timeStr;
}