IOS第16天(3,Quartz2D饼图）

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#import "HMPieView.h"
#import "UIColor+Random.h"
@implementation HMPieView

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
    }
    return self;
}

// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
    // Drawing code

    NSArray *data = @[@,@,@];

    // 1.获取上下文
    CGContextRef ctx = UIGraphicsGetCurrentContext();

    // 2.拼接路径
    CGPoint center = CGPointMake(, );
    CGFloat radius = ;
    CGFloat startA = ;
    CGFloat angle = ;
    CGFloat endA = ;

    for (NSNumber *number in data) {
        // 2.拼接路径
        startA = endA;
        angle = number.intValue / 100.0 * M_PI * ;
        endA = startA + angle;
        UIBezierPath *path = [UIBezierPath bezierPathWithArcCenter:center radius:radius startAngle:startA endAngle:endA clockwise:YES];
        [path addLineToPoint:center];

        [[UIColor randomColor] set];
        // 把路径添加上下文
        CGContextAddPath(ctx, path.CGPath);

        // 渲染
        CGContextFillPath(ctx);

    }

}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    CGFloat a = arc4random_uniform();
    //CGFloat a =  arc4random()%6;
    NSLog(@"随机数--%f",a);

    [self setNeedsDisplay];
}

- (void)drawPie
{
    // 1.获取上下文
    CGContextRef ctx = UIGraphicsGetCurrentContext();

    // 2.拼接路径
    CGPoint center = CGPointMake(, );
    CGFloat radius = ;
    CGFloat startA = ;
    CGFloat angle = ;
    CGFloat endA = ;

    // 第一个扇形
    angle =  / 100.0 * M_PI * ;
    endA = startA + angle;
    UIBezierPath *path = [UIBezierPath bezierPathWithArcCenter:center radius:radius startAngle:startA endAngle:endA clockwise:YES];
    [path addLineToPoint:center];
    // 添加到上下文
    CGContextAddPath(ctx, path.CGPath);
    [[UIColor redColor] set];

    // 渲染
    CGContextFillPath(ctx);

    // 第二个扇形
    startA = endA;
    angle =  / 100.0 * M_PI * ;
    endA = startA + angle;
    UIBezierPath *path1 = [UIBezierPath bezierPathWithArcCenter:center radius:radius startAngle:startA endAngle:endA clockwise:YES];
    [path1 addLineToPoint:center];
    // 添加到上下文
    CGContextAddPath(ctx, path1.CGPath);
    [[UIColor greenColor] set];
    // 渲染
    CGContextFillPath(ctx);

    // 第三个扇形
    startA = endA;
    angle =  / 100.0 * M_PI * ;
    endA = startA + angle;
    UIBezierPath *path2 = [UIBezierPath bezierPathWithArcCenter:center radius:radius startAngle:startA endAngle:endA clockwise:YES];
    [path2 addLineToPoint:center];
    // 添加到上下文
    CGContextAddPath(ctx, path2.CGPath);
    [[UIColor blueColor] set];
    // 渲染
    CGContextFillPath(ctx);

   }

@end