本篇写的是实现环形进度条，并带动画效果，要实现这些，仅能通过自己画一个
方法直接看代码 demo下载：LoopProgressViewDemo.zip
为了方便多次调用，用继承UIView的方式
.m文件
1 #import <UIKit/UIKit.h> 2 3 @interface LoopProgressView : UIView 4 5 @property (nonatomic, assign) CGFloat progress; 6 7 8 @end
.h文件
NSTimer的调用并非精确，可以自行百度
这里因为每0.01s启动一次定时器，所以要同步进度条和数字，就将self.progress赋值给动画的duration属性就可以了，duration为动画时间
在使用时我发现如果在tableviewcell中添加了这个环形进度条时有个缺点，就是定时器原本用的是系统的runloop，导致数据显示滞后，所以现更新为子线程里添加定时器，子线程的定时器必须添加
[[NSRunLoop currentRunLoop] run];才可启动定时器，因为子线程的runloop里是不带nstimer的，要手动添加运行
1 #import "LoopProgressView.h" 2 #import <QuartzCore/QuartzCore.h> 3 4 #define ViewWidth self.frame.size.width //环形进度条的视图宽度 5 #define ProgressWidth 2.5 //环形进度条的圆环宽度 6 #define Radius ViewWidth/2-ProgressWidth //环形进度条的半径 7 8 @interface LoopProgressView() 9 { 10 CAShapeLayer *arcLayer; 11 UILabel *label; 12 NSTimer *progressTimer; 13 } 14 @property (nonatomic,assign)CGFloat i; 15 16 @end 17 18 @implementation LoopProgressView 19 20 -(id)initWithFrame:(CGRect)frame 21 { 22 self = [super initWithFrame:frame]; 23 if (self) { 24 self.backgroundColor = [UIColor clearColor]; 25 } 26 return self; 27 } 28 29 -(void)drawRect:(CGRect)rect 30 { 31 _i=0; 32 CGContextRef progressContext = UIGraphicsGetCurrentContext(); 33 CGContextSetLineWidth(progressContext, ProgressWidth); 34 CGContextSetRGBStrokeColor(progressContext, 209.0/255.0, 209.0/255.0, 209.0/255.0, 1); 35 36 CGFloat xCenter = rect.size.width * 0.5; 37 CGFloat yCenter = rect.size.height * 0.5; 38 39 //绘制环形进度条底框 40 CGContextAddArc(progressContext, xCenter, yCenter, Radius, 0, 2*M_PI, 0); 41 CGContextDrawPath(progressContext, kCGPathStroke); 42 43 // //绘制环形进度环 44 CGFloat to = self.progress * M_PI * 2; // - M_PI * 0.5为改变初始位置 45 46 // 进度数字字号,可自己根据自己需要，从视图大小去适配字体字号 47 int fontNum = ViewWidth/6; 48
49 label = [[UILabel alloc]initWithFrame:CGRectMake(0, 0,Radius+10, ViewWidth/6)];
50 label.center = CGPointMake(xCenter, yCenter);
51 label.textAlignment = NSTextAlignmentCenter; 52 label.font = [UIFont boldSystemFontOfSize:fontNum]; 53 label.text = @"0%"; 54 [self addSubview:label]; 55 56 UIBezierPath *path=[UIBezierPath bezierPath]; 57 [path addArcWithCenter:CGPointMake(xCenter,yCenter) radius:Radius startAngle:0 endAngle:to clockwise:YES]; 58 arcLayer=[CAShapeLayer layer]; 59 arcLayer.path=path.CGPath;//46,169,230 60 arcLayer.fillColor = [UIColor clearColor].CGColor; 61 arcLayer.strokeColor=[UIColor colorWithRed:227.0/255.0 green:91.0/255.0 blue:90.0/255.0 alpha:0.7].CGColor; 62 arcLayer.lineWidth=ProgressWidth; 63 arcLayer.backgroundColor = [UIColor blueColor].CGColor; 64 [self.layer addSublayer:arcLayer]; 65 66 67 dispatch_async(dispatch_get_global_queue(0, 0), ^{ 68 [self drawLineAnimation:arcLayer]; 69 }); 70 71 if (self.progress > 1) { 72 NSLog(@"传入数值范围为 0-1"); 73 self.progress = 1; 74 }else if (self.progress < 0){ 75 NSLog(@"传入数值范围为 0-1"); 76 self.progress = 0; 77 return; 78 } 79 80 if (self.progress > 0) { 81 NSThread *thread = [[NSThread alloc]initWithTarget:self selector:@selector(newThread) object:nil]; 82 [thread start]; 83 } 84 85 } 86 87 -(void)newThread 88 { 89 @autoreleasepool { 90 progressTimer = [NSTimer scheduledTimerWithTimeInterval:0.01 target:self selector:@selector(timeLabel) userInfo:nil repeats:YES]; 91 [[NSRunLoop currentRunLoop] run]; 92 } 93 } 94 95 //NSTimer不会精准调用 96 -(void)timeLabel 97 { 98 _i += 0.01; 99 label.text = [NSString stringWithFormat:@"%.0f%%",_i*100]; 100 101 if (_i >= self.progress) {
102 [progressTimer invalidate];
103 progressTimer = nil; 104 105 } 106 107 } 108 109 //定义动画过程 110 -(void)drawLineAnimation:(CALayer*)layer 111 { 112 CABasicAnimation *bas=[CABasicAnimation animationWithKeyPath:@"strokeEnd"]; 113 bas.duration=self.progress;//动画时间 114 bas.delegate=self; 115 bas.fromValue=[NSNumber numberWithInteger:0]; 116 bas.toValue=[NSNumber numberWithInteger:1]; 117 [layer addAnimation:bas forKey:@"key"]; 118 } 119 120 @end
完成后在要调用的控制器里，仅需几段代码：传进的参数：为0-1
1 LoopProgressView *custom = [[LoopProgressView alloc]initWithFrame:CGRectMake(50, 100, 100, 100)]; 2 custom.progress = 0.44; 3 [self.view addSubview:custom];
实现后：
已经实现进度条和数字的同步：
