iOS开发-下载进度条的环形动画 包括使用AFN下载的示例

前言

iOS开发中会遇到很多需要使用进度条表示下载进度的地方。

如图

代码

• 首先是环形动画的封装
• ShowProgress.h

#import <UIKit/UIKit.h>

NS_ASSUME_NONNULL_BEGIN

@interface ShowProgress : UIView

@property(nonatomic, assign) CGFloat progress;
@property(nonatomic, strong) UIColor *progressBarColor;

@end

NS_ASSUME_NONNULL_END

• ShowProgress.m

#import "ShowProgress.h"

@implementation ShowProgress

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

- (void)drawRect:(CGRect)rect {
    
    
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    CGFloat xCenter = rect.size.width * 0.5;
    CGFloat yCenter = rect.size.height * 0.5;
    
    [_progressBarColor set];
    
    //设置圆环的宽度
    CGContextSetLineWidth(ctx, 2); //1.5 圆环的宽度
    CGContextSetLineCap(ctx, kCGLineCapRound);
    CGFloat to = - M_PI * 0.5 + self.progress * M_PI * 2; // 初始值0.05
    //半径
    CGFloat radius = rect.size.width * 0.5 - 1;
    CGContextAddArc(ctx, xCenter, yCenter, radius, - M_PI * 0.5, to, 0);
    CGContextStrokePath(ctx);
}

- (void)setProgress:(CGFloat)progress {
    
    
    _progress = progress;
    if (_progress >= 1) {
    
    
        [self removeFromSuperview];
    } else {
    
    
        [self setNeedsDisplay];
    }
}

@end

使用

• 一般是用AFN进行下载

#pragma mark - AFN 下载

- (void)downLoadUrl:(NSString *)urlString
      progressBlock:(DownProgressBlock _Nullable)progressBlock
   downSuccessBlock:(DownSuccessBlock _Nullable)downSuccessBlock
    downFailedBlock:(DownFailedBlock _Nullable)downFailedBlock {
    
    
    AFHTTPSessionManager *manager = [self manager];
    //2.1 创建请求对象
    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:urlString]];
    __weak typeof(self) weakSelf = self;
    NSURLSessionDownloadTask *downloadTask = [manager downloadTaskWithRequest:request progress:^(NSProgress *downloadProgress) {
    
     //进度
        CGFloat rate = (100.0 * downloadProgress.completedUnitCount / downloadProgress.totalUnitCount);
        [weakSelf _getMainThread:^{
    
    
            if (progressBlock) {
    
    
                progressBlock(rate);
            }
        }];
    } destination:^NSURL *(NSURL *targetPath, NSURLResponse *response) {
    
    
        NSString *caches = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];
        //response.suggestedFilename后缀名 xxx.mp4
        //https://dl.anycdn.cc/data/static/ay/bao.zip
        NSString *fullpath = [caches stringByAppendingPathComponent:response.suggestedFilename];
        NSURL *filePathUrl = [NSURL fileURLWithPath:fullpath];

        return filePathUrl;
    } completionHandler:^(NSURLResponse *response, NSURL *filePath, NSError *error) {
    
     //都在主线程
        if (error) {
    
     //加载失败
            downFailedBlock(error);
        }

        NSString *file = [[filePath absoluteString] stringByReplacingOccurrencesOfString:@"file://" withString:@""];
        NSString *caches = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];
        if(filePath) {
    
     //加载成功返回路径
            downSuccessBlock(file, caches);
        }
    }];

    //3.启动任务
    [downloadTask resume];
}

- (AFHTTPSessionManager *)manager {
    
    
    static AFHTTPSessionManager *manager = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
    
    
        if (manager == nil) {
    
    
            manager = [AFHTTPSessionManager manager];
            manager.requestSerializer.timeoutInterval = kTimeoutInterval;
        }
    });
    return manager;
}

#pragma mark - AFN 下载 end

• 通过一个计时器对环形动画的进度填充 ViewController.m

#import "ViewController.h"
#import "ShowProgress.h"

static NSInteger const kMaxTime = 10;
@interface ViewController ()

@property(nonatomic, strong) UIView *backView;
@property(nonatomic, strong) ShowProgress *_Nullable progressView; //下载进度页面
@property(nonatomic, strong) NSTimer *timer;
@property(nonatomic, assign) NSInteger count;

@end

@implementation ViewController

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    
    
    [self startTask];
}

- (void)viewDidLoad {
    
    
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor lightGrayColor];
    [self.view addSubview:self.backView];
}

- (UIView *)backView {
    
    
    if(_backView == nil) {
    
    
        _backView = [[UIView alloc]initWithFrame:CGRectMake((self.view.frame.size.width - 100) / 2, (self.view.frame.size.height - 100) / 2, 100, 100)];
        _backView.backgroundColor = [UIColor clearColor];
        _backView.layer.borderColor = [UIColor whiteColor].CGColor;
        _backView.layer.borderWidth = 2;
        _backView.layer.cornerRadius = self.backView.frame.size.width / 2;
        _backView.clipsToBounds = YES;
        _backView.hidden = YES;
    }
    return _backView;
}

- (ShowProgress *)progressView {
    
    
    if(_progressView == nil) {
    
    
        _progressView = [[ShowProgress alloc]initWithFrame:CGRectMake((self.view.frame.size.width - 100) / 2, (self.view.frame.size.height - 100) / 2, 100, 100)];
    }
    return _progressView;
}

- (void)startTask {
    
     //开始
    self.backView.hidden = NO;
    [self.view addSubview:self.progressView];
    
    _timer = [NSTimer scheduledTimerWithTimeInterval:kMaxTime target:self selector:@selector(taskAction) userInfo:nil repeats:YES];
    [[NSRunLoop currentRunLoop] addTimer:_timer forMode:NSDefaultRunLoopMode];
}

- (void)endTask {
    
     //结束
    [_timer invalidate];
    _timer = nil;
    self.progressView = nil;
    [self.progressView removeFromSuperview];
}

- (void)taskAction {
    
    
    if(_count == kMaxTime) {
    
    
        [self endTask];
    }
    [self.progressView setProgress:_count * 0.1];
    _count ++;
}

@end

• 关联使用将AFN返回的下载进度对self.progressView 的setProgress:方法，进行填充，既有动画