iOS实践：根据进度绘制进度条、进度扇形、进度球1. 效果展示及思维导图2. 项目准备工作3. 进度条的实现4. 扇形进度指示器5. 球形指示器

@property (weak, nonatomic) IBOutlet UIProgressView *lineView;

- (IBAction)sliderValueChanged:(UISlider *)sender {
    
    //    对进度条进行赋值，同时对数值进行安全处理
    self.lineView.progress  =  (sender.value - sender.minimumValue) / (sender.maximumValue - sender.minimumValue);
}

@interface SectorProgress : UIView
@property(assign,nonatomic)CGFloat progress;
@property(weak,nonatomic) IBOutlet UILabel *progressLabel;

@end


- (void)drawRect:(CGRect)rect {
//    定义扇形中心
    CGPoint origin = CGPointMake(100, 100);
//    定义扇形半径
    CGFloat radius = 100.0f;
    
//    设定扇形起点位置
    CGFloat startAngle = - M_PI_2;
//    根据进度计算扇形结束位置
    CGFloat endAngle = startAngle + self.progress * M_PI * 2;
    
//    根据起始点、原点、半径绘制弧线
    UIBezierPath *sectorPath = [UIBezierPath bezierPathWithArcCenter:origin radius:radius startAngle:startAngle endAngle:endAngle clockwise:YES];
    
//    从弧线结束为止绘制一条线段到圆心。这样系统会自动闭合图形，绘制一条从圆心到弧线起点的线段。
    [sectorPath addLineToPoint:origin];
    
//    设置扇形的填充颜色
    [[UIColor darkGrayColor] set];
    
//    设置扇形的填充模式
    [sectorPath fill];
}


//重写progress的set方法，可以在赋值的同时给label赋值
- (void)setProgress:(CGFloat)progress{
    _progress = progress;
    
//    对label进行赋值
    self.progressLabel.text = [NSString stringWithFormat:@"%0.2f%%",progress * 100];
//    赋值结束之后要刷新UI，不然看不到扇形的变化
    [self setNeedsDisplay];
}

@interface BallProgress ()
@property(assign,nonatomic)CGFloat progress;
@property(assign,nonatomic)CGFloat startAngle;
@property(assign,nonatomic)CGFloat endAngle;

@property(weak,nonatomic) IBOutlet UILabel *progressLabel;


@end

- (void)drawRect:(CGRect)rect {
    CGPoint origin = CGPointMake(100, 100);
    CGFloat radius = 95.0f;
    
    UIBezierPath *ballPath = [UIBezierPath bezierPathWithArcCenter:origin radius:radius startAngle:_startAngle endAngle:_endAngle clockwise:YES];
    
    [[UIColor purpleColor]set];
    [ballPath fill];
    
//    在球形的外面绘制一个描边空心的圆形，不然很难看
    UIBezierPath *strokePath = [UIBezierPath bezierPathWithArcCenter:origin radius:radius startAngle:0 endAngle:-0.00000001 clockwise:YES];
    [[UIColor lightGrayColor]set];
    [strokePath stroke];
}


- (void)setProgress:(CGFloat)progress{
    _progress = progress;
    
//    设置起始点，位置是根据进度动态变换的
    self.startAngle = M_PI_2 - progress * M_PI;
    self.endAngle = M_PI_2 + progress * M_PI;
    
    self.progressLabel.text = [NSString stringWithFormat:@"%0.2f%%",progress * 100];
    
    [self setNeedsDisplay];
}