iOS 给webView加进度条(WKWebView)

1.导入头文件

#import  

2.创建WKWebView和ProcessView, 并且添加观察着

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

- (void)viewDidLoad {
    [super viewDidLoad];
    _webView = [[WKWebView alloc] initWithFrame:self.view.bounds];
    _webView.UIDelegate = self;
    _webView.navigationDelegate = self;
    [self.view addSubview:_webView];
    
    _progressView = [[UIProgressView alloc]initWithFrame:CGRectMake(0, 65, CGRectGetWidth(self.view.frame),2)];
    [self.view addSubview:_progressView];
    
    [_webView addObserver:self forKeyPath:@"estimatedProgress" options:NSKeyValueObservingOptionNew| NSKeyValueObservingOptionOld context:nil];
    [_webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.baidu.com"]]];

}

3. 实现代理方法

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context{
    NSLog(@" %s,change = %@",__FUNCTION__,change);
    if ([keyPath isEqual: @"estimatedProgress"] && object == _webView) {
        [self.progressView setAlpha:1.0f];
        [self.progressView setProgress:_webView.estimatedProgress animated:YES];
            if(_webView.estimatedProgress >= 1.0f)
            {
                [UIView animateWithDuration:0.3 delay:0.3 options:UIViewAnimationOptionCurveEaseOut animations:^{
                    [self.progressView setAlpha:0.0f];
                } completion:^(BOOL finished) {
                    [self.progressView setProgress:0.0f animated:NO];
                }];
            }
    }
    else {
        [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
    }
}

4.移除观察者

- (void)dealloc {
    [_webView removeObserver:self forKeyPath:@"estimatedProgress"];
    
    // if you have set either WKWebView delegate also set these to nil here
    [_webView setNavigationDelegate:nil];
    [_webView setUIDelegate:nil];
}