• ios开发之--给WebView加载进度条


    不是新东西,就是在项目里面用到H5页面的时候,中间加载延迟的时候,在最上面加载一个进度条,代码如下:

    // 获取屏幕 宽度、高度 bounds就是屏幕的全部区域
    #define KDeviceWidth    [UIScreen mainScreen].bounds.size.width
    #define KDeviceHeight   [UIScreen mainScreen].bounds.size.height
    
    #define IS_IPHONE_X (KDeviceHeight == 812.0f) ? YES : NO
    
    #define Height_NavBar ((IS_IPHONE_X) ? 88.0f : 64.0f)
    
    #define Height_NavContentBar 64.0f
    
    
    #import "OtherViewController.h"
    
    @interface OtherViewController ()<WKUIDelegate,WKNavigationDelegate>
    
    @property (nonatomic, strong) WKWebViewConfiguration *wkConfig;
    /*
     *1.添加UIProgressView属性
     */
    @property (nonatomic, strong) UIProgressView *progressView;
    
    @property (nonatomic, strong) WKWebView *wkWebView;
    
    @end
    
    @implementation OtherViewController
    
    #pragma mark - 初始化wkWebView
    
    - (WKWebViewConfiguration *)wkConfig {
        if (!_wkConfig) {
            _wkConfig = [[WKWebViewConfiguration alloc] init];
            _wkConfig.allowsInlineMediaPlayback = YES;
            if (@available(iOS 10.0, *)) {
                _wkConfig.allowsPictureInPictureMediaPlayback = YES;
            } else {
                // Fallback on earlier versions
            }
        }
        return _wkConfig;
    }
    
    - (WKWebView *)wkWebView {
        if (!_wkWebView) {
            _wkWebView = [[WKWebView alloc] initWithFrame:CGRectMake(0, Height_NavBar, KDeviceWidth, KDeviceHeight) configuration:self.wkConfig];
            _wkWebView.navigationDelegate = self;
            _wkWebView.UIDelegate = self;
            [self.view addSubview:_wkWebView];
        }
        return _wkWebView;
    }
    
    /*
     *6.在dealloc中取消监听
     */
    
    - (void)dealloc {
        if (self.progressView) {
            [self.progressView removeFromSuperview];
            self.progressView = nil;
        }
        [self.wkWebView removeObserver:self forKeyPath:@"estimatedProgress"];
    }
    
    - (void)viewDidLoad {
        [super viewDidLoad];
        // Do any additional setup after loading the view.
        
        /*
         *2.初始化progressView
         */
        self.progressView = [[UIProgressView alloc] initWithFrame:CGRectMake(0, 44, [[UIScreen mainScreen] bounds].size.width, 2)];
        self.progressView.backgroundColor = [UIColor whiteColor];
        self.progressView.progressImage = [UIImage imageNamed:@"WKProgress"];
        //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.navigationController.navigationBar addSubview:self.progressView];
        [self.navigationController.navigationBar 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];
        
        [self loadWebViewWithUrl:@"http://www.pc6.com/apple/"];
    }
    
    - (void)viewWillDisappear:(BOOL)animated{
        [super viewWillDisappear:animated];
        [self.progressView removeFromSuperview];
        self.progressView = nil;
    }
    
    #pragma mark - start load web
    
    - (void)loadWebViewWithUrl:(NSString *)url{
        NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:url]];
        request.timeoutInterval = 15.0f;
        [self.wkWebView loadRequest:request];
    }
    
    #pragma mark - 监听
    
    /*
     *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"]) {
            NSLog(@"%.2f,",self.wkWebView.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
                 *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];
        }
    }
    
    #pragma mark - WKWKNavigationDelegate Methods
    
    /*
     *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.navigationController.navigationBar 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;
    }
    
    //页面跳转
    - (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {
        //允许页面跳转
        NSLog(@"%@",navigationAction.request.URL);
        decisionHandler(WKNavigationActionPolicyAllow);
    }

    思路是:给WKWebView添加一个观察者,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,然后再开始加载网页的时候显示progress,在加载完成或者失败的时候,把progress隐藏就可以了!

    仅做记录!

    效果如下:

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  • 原文地址:https://www.cnblogs.com/hero11223/p/9690573.html
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