iOS WKWebView添加网页加载进度条(转)

一、效果展示

WKWebProgressViewDemo.gif

二、主要步骤

1.添加UIProgressView属性

@property (nonatomic, strong) WKWebView *wkWebView; @property (nonatomic, strong) UIProgressView *progressView;

2.初始化progressView

- (void)viewDidLoad { [super viewDidLoad]; //进度条初始化 self.progressView = [[UIProgressView alloc] initWithFrame:CGRectMake(0, 20, [[UIScreen mainScreen] bounds].size.width, 2)]; self.progressView.backgroundColor = [UIColor blueColor]; //设置进度条的高度，下面这句代码表示进度条的宽度变为原来的1倍，高度变为原来的1.5倍. self.progressView.transform = CGAffineTransformMakeScale(1.0f, 1.5f); [self.view addSubview:self.progressView]; }

3.添加KVO，WKWebView有一个属性estimatedProgress，就是当前网页加载的进度，所以监听这个属性。

[self.wkWebView addObserver:self forKeyPath:@"estimatedProgress" options:NSKeyValueObservingOptionNew context:nil];

4.在监听方法中获取网页加载的进度，并将进度赋给progressView.progress

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSString *,id> *)change context:(void *)context { if ([keyPath isEqualToString:@"estimatedProgress"]) { self.progressView.progress = self.wkWebView.estimatedProgress; if (self.progressView.progress == 1) { /* *添加一个简单的动画，将progressView的Height变为1.4倍，在开始加载网页的代理中会恢复为1.5倍 *动画时长0.25s，延时0.3s后开始动画 *动画结束后将progressView隐藏 */ __weak typeof (self)weakSelf = self; [UIView animateWithDuration:0.25f delay:0.3f options:UIViewAnimationOptionCurveEaseOut animations:^{ weakSelf.progressView.transform = CGAffineTransformMakeScale(1.0f, 1.4f); } completion:^(BOOL finished) { weakSelf.progressView.hidden = YES; }]; } }else{ [super observeValueForKeyPath:keyPath ofObject:object change:change context:context]; } }

5.在WKWebViewd的代理中展示进度条，加载完成后隐藏进度条

//开始加载 - (void)webView:(WKWebView *)webView didStartProvisionalNavigation:(WKNavigation *)navigation { NSLog(@"开始加载网页"); //开始加载网页时展示出progressView self.progressView.hidden = NO; //开始加载网页的时候将progressView的Height恢复为1.5倍 self.progressView.transform = CGAffineTransformMakeScale(1.0f, 1.5f); //防止progressView被网页挡住 [self.view bringSubviewToFront:self.progressView]; } //加载完成 - (void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation { NSLog(@"加载完成"); //加载完成后隐藏progressView //self.progressView.hidden = YES; } //加载失败 - (void)webView:(WKWebView *)webView didFailProvisionalNavigation:(WKNavigation *)navigation withError:(NSError *)error { NSLog(@"加载失败"); //加载失败同样需要隐藏progressView //self.progressView.hidden = YES; }

6.在dealloc中取消监听

- (void)dealloc { [self.wkWebView removeObserver:self forKeyPath:@"estimatedProgress"]; }

三、github 代码地址

请戳这里查看demo