1、獲取加載進度：

使用KOV來觀察

[webView addObserver:selfforKeyPath:@"estimatedProgress"options:NSKeyValueObservingOptionNew context:NULL];

2、獲取Title

[webView addObserver:selfforKeyPath:@"title"options:NSKeyValueObservingOptionNew context:NULL];

然后重寫KVO的實現方法

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
    if (object == webView) {
        if ([keyPath isEqualToString:@"estimatedProgress"]) {
            //加載進度
            [progressView setAlpha:1.0f];
            [progressView setProgress:webView.estimatedProgress animated:YES];
            if(webView.estimatedProgress >= 1.0f) {
                [UIView animateWithDuration:0.3 delay:0.3 options:UIViewAnimationOptionCurveEaseOut animations:^{
                    [progressView setAlpha:0.0f];
                } completion:^(BOOL finished) {
                    [progressView setProgress:0.0f animated:NO];
                }];
            }
        } else if ([keyPath isEqualToString:@"title"]) {
            //頁面標題
            self.title = webView.title;
        }
    } else {
        [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
    }
}

3、返回某個歷史頁面

- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {
    if (navigationAction.navigationType==WKNavigationTypeBackForward) {                  //判斷是返回類型
        if (webView.backForwardList.backList.count>0) {                                  //得到棧里面的list
            WKBackForwardListItem * item = webView.backForwardList.currentItem;          //得到現在加載的list
            for (WKBackForwardListItem * backItem inwebView.backForwardList.backList) { //循環遍歷，得到你想退出到
                //添加判斷條件
                [webView goToBackForwardListItem:[webView.backForwardList.backListfirstObject]];
            }
        }
    }
    //允許跳轉
    decisionHandler(WKNavigationActionPolicyAllow);
}

4、清除緩存

- (void)deleteWebCache {
    if ([[UIDevice currentDevice].systemVersion floatValue] >= 9.0) {
        //系統版本高于iOS9
        NSSet *websiteDataTypes
        = [NSSet setWithArray:@[
                                WKWebsiteDataTypeDiskCache,
                                WKWebsiteDataTypeMemoryCache,
                                ]];
        //// All kinds of data
        //NSSet *websiteDataTypes = [WKWebsiteDataStore allWebsiteDataTypes];
        //// Date from
        NSDate *dateFrom = [NSDate dateWithTimeIntervalSince1970:0];
        //// Execute
        [[WKWebsiteDataStore defaultDataStore] removeDataOfTypes:websiteDataTypes modifiedSince:dateFrom completionHandler:^{
            // Done
        }];
    } else {
        //系統版本低于iOS9
        NSString *libraryPath = [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES) objectAtIndex:0];
        NSString *cookiesFolderPath = [libraryPath stringByAppendingString:@"/Cookies"];
        NSError *errors;
        [[NSFileManager defaultManager] removeItemAtPath:cookiesFolderPath error:&errors];
    }
}