WKWebView 的简单使用

相比UIWebView 的优点 占用内存少 加载速度快

1. 创建

WKWebView *webView = [[WKWebView alloc]initWithFrame:CGRectMake(0, 0,Screen_Width, Screen_Height)];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];
// 取消掉回弹效果
    webView.scrollView.bounces = NO ;
    [webView loadRequest:request];
    [self.view addSubview:webView];

2.添加加载进度条
该部分来源http://blog.csdn.net/hdfqq188816190/article/details/51382388

UIView *progress = [[UIView alloc]initWithFrame:CGRectMake(0, 23, CGRectGetWidth(self.view.frame), 2)];
    progress.backgroundColor = [UIColor clearColor];
    [self.view addSubview:progress];
    
    CALayer *layer = [CALayer layer];
    layer.frame = CGRectMake(0, 0, 0, 3);
    layer.backgroundColor = Theme_Blue.CGColor;
    [progress.layer addSublayer:layer];
    self.progresslayer = layer;

// 给wkwebView 添加观察者

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

// 实现监听方法

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSString *,id> *)change context:(void *)context{
    if ([keyPath isEqualToString:@"estimatedProgress"]) {
        self.progresslayer.opacity = 1;
        //不要让进度条倒着走...有时候goback会出现这种情况
        if ([change[@"new"] floatValue] < [change[@"old"] floatValue]) {
            return;
        }
        self.progresslayer.frame = CGRectMake(0, 0, self.view.bounds.size.width * [change[@"new"] floatValue], 2);
        if ([change[@"new"] floatValue] == 1) {
            dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(.4 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
                self.progresslayer.opacity = 0;
            });
            dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(.5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
                self.progresslayer.frame = CGRectMake(0, 0, 0, 2);
            });
        }
    }else{
        [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
    }
}

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

3.self.view 上添加webview 后 添加的点击手势会被拦截而无法执行
解决办法(这样可以执行自定义的手势 但是无法屏蔽掉webview 自带的手势 也就是说如果webview 和 self.view 都有添加双击手势的话两者都会被执行)

实现手势的代理方法

// 所在的类遵守协议UIGestureRecognizerDelegate
// 设置添加手势的代理为self
@interface UIViewController ()<UIGestureRecognizerDelegate>

-(void)addTapGestureRecoginize{
    
    UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(bactToListView)];
    doubleTap.delegate = self ;
    [doubleTap setNumberOfTapsRequired:2];
    [self.view addGestureRecognizer:doubleTap];
   
}
-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{

    return YES ;
}