转圈圈定制加载中视图

//
//  HYCircleLoadingView.h
//  HYCircleLoadingViewExample
//
//  Created by Shadow on 14-3-7.
//  Copyright (c) 2014年 Shadow. All rights reserved.
//

#import <UIKit/UIKit.h>

/*!
 * @brief 圆形转圈圈加载等待视图
 * @author huangyibiao
 */
@interface HYBCircleLoadingView : UIView

// 线宽
// default is 1.0f
@property (nonatomic, assign) CGFloat lineWidth;

// 线的颜色
// default is [UIColor lightGrayColor]
@property (nonatomic, strong) UIColor *lineColor;

// 是否添加动画
// default is YES
@property (nonatomic, readonly) BOOL isAnimating;

// 开始、结束动画效果
- (void)startAnimation;
// 结束动画的时候会移除掉
- (void)stopAnimation;

@end

//
//  HYCircleLoadingView.m
//  HYCircleLoadingViewExample
//
//  Created by Shadow on 14-3-7.
//  Copyright (c) 2014年 Shadow. All rights reserved.
//

#import "HYBCircleLoadingView.h"

#define kAngelWithDegree(degree) (2 * M_PI / 360 * degree)

@interface HYBCircleLoadingView ()

// 角度
// 0.0 - 1.0
@property (nonatomic, assign) CGFloat angel;

@end

@implementation HYBCircleLoadingView

- (id)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if (self) {
        self.backgroundColor = [UIColor clearColor];
    }
    return self;
}

- (id)init {
    return [self initWithFrame:CGRectZero];
}

- (void)setAngel:(CGFloat)angel {
    _angel = angel;
    [self setNeedsDisplay];
    return;
}

- (void)startAnimation {
    if (self.isAnimating) {
        [self stopAnimation];
        [self.layer removeAllAnimations];
    }
    _isAnimating = YES;
    
    self.angel = kAngelWithDegree(30);
    [self startRotateAnimation];
    return;
}

- (void)stopAnimation {
    _isAnimating = NO;
    [self stopRotateAnimation];
    return;
}

- (void)startRotateAnimation {
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
    animation.fromValue = @(0);
    animation.toValue = @(2 * M_PI);
    animation.duration = 0.9f;
    animation.repeatCount = INT_MAX;
    [self.layer addAnimation:animation forKey:@"keyFrameAnimation"];
    
    [UIView animateWithDuration:0.3f animations:^{
        self.alpha = 1.0;
    } completion:nil];
    return;
}

- (void)stopRotateAnimation {
    [UIView animateWithDuration:0.3f animations:^{
        self.alpha = 0;
    } completion:^(BOOL finished) {
        _angel = 0;
        [self.layer removeAllAnimations];
    }];
    return;
}

- (void)drawRect:(CGRect)rect {
    if (self.angel <= 0) {
        _angel = 0;
    }
    
    CGFloat lineWidth = 1.f;
    UIColor *lineColor = [UIColor blueColor];
    if (self.lineWidth) {
        lineWidth = self.lineWidth;
    }
    if (self.lineColor) {
        lineColor = self.lineColor;
    }
    
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetLineWidth(context, lineWidth);
    CGContextSetStrokeColorWithColor(context, lineColor.CGColor);
    CGContextAddArc(context,
                    CGRectGetMidX(self.bounds), CGRectGetMidY(self.bounds),
                    CGRectGetWidth(self.bounds)/2-lineWidth,
                    kAngelWithDegree(120),
                    kAngelWithDegree(120) + kAngelWithDegree(330) * self.angel,
                    0);
    CGContextStrokePath(context);
    return;
}

@end