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

为了方便多次调用，用继承UIView的方式

.m文件

#import <UIKit/UIKit.h>@interface LoopProgressView : UIView@property (nonatomic, assign) CGFloat progress;@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。

#import "LoopProgressView.h"#import <QuartzCore/QuartzCore.h>#define ViewWidth self.frame.size.width //环形进度条的视图宽度#define ProgressWidth 2.5 //环形进度条的圆环宽度#define Radius ViewWidth/2-ProgressWidth //环形进度条的半径@interface LoopProgressView(){ CAShapeLayer *arcLayer; UILabel *label; NSTimer *progressTimer;}@property (nonatomic,assign)CGFloat i;@end@implementation LoopProgressView-(id)initWithFrame:(CGRect)frame{ self = [super initWithFrame:frame]; if (self) { self.backgroundColor = [UIColor clearColor]; } return self;}-(void)drawRect:(CGRect)rect{ _i=0; CGContextRef progressContext = UIGraphicsGetCurrentContext(); CGContextSetLineWidth(progressContext, ProgressWidth); CGContextSetRGBStrokeColor(progressContext, 209.0/255.0, 209.0/255.0, 209.0/255.0, 1); CGFloat xCenter = rect.size.width * 0.5; CGFloat yCenter = rect.size.height * 0.5; //绘制环形进度条底框 CGContextAddArc(progressContext, xCenter, yCenter, Radius, 0, 2*M_PI, 0); CGContextDrawPath(progressContext, kCGPathStroke); // //绘制环形进度环 CGFloat to = self.progress * M_PI * 2; // - M_PI * 0.5为改变初始位置 // 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 int fontNum = ViewWidth/6; 49 label = [[UILabel alloc]initWithFrame:CGRectMake(0, 0,Radius+10, ViewWidth/6)]; label.center = CGPointMake(xCenter, yCenter); label.textAlignment = NSTextAlignmentCenter; label.font = [UIFont boldSystemFontOfSize:fontNum]; label.text = @"0%"; [self addSubview:label]; UIBezierPath *path=[UIBezierPath bezierPath]; [path addArcWithCenter:CGPointMake(xCenter,yCenter) radius:Radius startAngle:0 endAngle:to clockwise:YES]; arcLayer=[CAShapeLayer layer]; arcLayer.path=path.CGPath;//46,169,230 arcLayer.fillColor = [UIColor clearColor].CGColor; arcLayer.strokeColor=[UIColor colorWithRed:227.0/255.0 green:91.0/255.0 blue:90.0/255.0 alpha:0.7].CGColor; arcLayer.lineWidth=ProgressWidth; arcLayer.backgroundColor = [UIColor blueColor].CGColor; [self.layer addSublayer:arcLayer]; dispatch_async(dispatch_get_global_queue(0, 0), ^{ [self drawLineAnimation:arcLayer]; }); if (self.progress > 1) { NSLog(@"传入数值范围为 0-1"); self.progress = 1; }else if (self.progress < 0){ NSLog(@"传入数值范围为 0-1"); self.progress = 0; return; } if (self.progress > 0) { NSThread *thread = [[NSThread alloc]initWithTarget:self selector:@selector(newThread) object:nil]; [thread start]; } }-(void)newThread{ @autoreleasepool { progressTimer = [NSTimer scheduledTimerWithTimeInterval:0.01 target:self selector:@selector(timeLabel) userInfo:nil repeats:YES]; [[NSRunLoop currentRunLoop] run]; }}//NSTimer不会精准调用-(void)timeLabel{ _i += 0.01; label.text = [NSString stringWithFormat:@"%.0f%%",_i*100]; if (_i >= self.progress) { [progressTimer invalidate]; progressTimer = nil; } }//定义动画过程-(void)drawLineAnimation:(CALayer*)layer{ CABasicAnimation *bas=[CABasicAnimation animationWithKeyPath:@"strokeEnd"]; bas.duration=self.progress;//动画时间 bas.delegate=self; bas.fromValue=[NSNumber numberWithInteger:0]; bas.toValue=[NSNumber numberWithInteger:1]; [layer addAnimation:bas forKey:@"key"];}@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

LoopProgressView *custom = [[LoopProgressView alloc]initWithFrame:CGRectMake(50, 100, 100, 100)]; custom.progress = 0.44; [self.view addSubview:custom];

实现：

已经实现进度条和数字的同步：

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。