new/二期/Scenes/首页/WKWebViewVC.m

//
//  WKWebViewVC.m
//  PoliceHome
//
//  Created by 刘惠萍 on 2020/12/15.
//  Copyright © 2020 刘惠萍. All rights reserved.
//

#import "WKWebViewVC.h"
#import <WebKit/WebKit.h>

@interface WKWebViewVC ()<WKNavigationDelegate>

@property (nonatomic, strong) WKWebView * webView;
///网页加载进度视图
@property (nonatomic, strong) UIProgressView * progressView;
/// WKWebView 内容的高度
@property (nonatomic, assign) CGFloat webContentHeight;
@property (nonatomic, strong) BaseNavView *navView;

@end

@implementation WKWebViewVC
- (BaseNavView *)navView{
    if (!_navView) {
        _navView = [BaseNavView initNavBackTitle:UnPackStr(self.navStr) rightView:nil];
        WEAKSELF
        _navView.blockBack = ^{
            if (weakSelf.webView.canGoBack) {
                [weakSelf.webView goBack];
            }else{
                [GB_Nav popViewControllerAnimated:true];
            }
        };
    }
    return _navView;
}
#pragma mark - Override
- (void)viewDidLoad {
    [super viewDidLoad];
    if (self.isNav) {
        [self.view addSubview:self.navView];
    }
    [self setupUI];
    [self addKVO];
}
- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
    [self.progressView removeFromSuperview];
}
- (void)dealloc {
    [self removeKVO];
    [NSURLProtocol registerClass:[NSURLProtocol class]];
}

#pragma mark - UI
- (void)setupUI {
    self.view.backgroundColor = UIColor.whiteColor;
    
    //设置自定义Cookie在WKWebView初始化之前
    
    [self.view addSubview:self.webView];
}

#pragma mark - Getter
- (WKWebView *)webView {
    if(_webView == nil){
        //创建网页配置
        WKWebViewConfiguration *config = [[WKWebViewConfiguration alloc] init];
        _webView = [[WKWebView alloc] initWithFrame:CGRectMake(0, self.isNav?NAVIGATIONBAR_HEIGHT:0, SCREEN_WIDTH, self.isNav?SCREEN_HEIGHT-NAVIGATIONBAR_HEIGHT:self.isHight?SCREEN_HEIGHT-NAVIGATIONBAR_HEIGHT-W(55)-W(84):SCREEN_HEIGHT) configuration:config];
        _webView.navigationDelegate = self;
        //以下代码适配文本大小
        NSString *jSString = @"var meta = document.createElement('meta'); meta.setAttribute('name', 'viewport'); meta.setAttribute('content', 'width=device-width'); document.getElementsByTagName('head')[0].appendChild(meta);";
        //用于进行JavaScript注入
        WKUserScript *wkUScript = [[WKUserScript alloc] initWithSource:jSString injectionTime:WKUserScriptInjectionTimeAtDocumentEnd forMainFrameOnly:YES];
        [config.userContentController addUserScript:wkUScript];
        _webView.allowsBackForwardNavigationGestures = YES;
        if (self.isH5) {
            NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:UnPackStr(self.htmlString)]];
            [_webView loadRequest:request];
        }else{
        [_webView loadHTMLString:UnPackStr(self.htmlString) baseURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] bundlePath]]];
        }
    }
    return _webView;
}
- (UIProgressView *)progressView {
    if (!_progressView){
        _progressView = [[UIProgressView alloc] initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH, 2)];
        _progressView.tintColor = [UIColor blueColor];
        _progressView.trackTintColor = [UIColor clearColor];
    }
    if (_progressView.superview == nil) {
        [self.navigationController.navigationBar addSubview:_progressView];
    }
    return _progressView;
}

#pragma mark - KVO
///添加键值对监听
- (void)addKVO {
    //监听网页加载进度
    [self.webView addObserver:self
                   forKeyPath:NSStringFromSelector(@selector(estimatedProgress))
                      options:NSKeyValueObservingOptionNew
                      context:nil];
    [self.webView addObserver:self
                   forKeyPath:@"title"
                      options:NSKeyValueObservingOptionNew
                      context:nil];
}
///移除监听
- (void)removeKVO {
    //移除观察者
    [_webView removeObserver:self
                  forKeyPath:NSStringFromSelector(@selector(estimatedProgress))];
    [_webView removeObserver:self
                  forKeyPath:NSStringFromSelector(@selector(title))];
}
//kvo监听 必须实现此方法
-(void)observeValueForKeyPath:(NSString *)keyPath
                     ofObject:(id)object
                       change:(NSDictionary<NSKeyValueChangeKey,id> *)change
                      context:(void *)context{
    
    if ([keyPath isEqualToString:NSStringFromSelector(@selector(estimatedProgress))]
        && object == _webView) {
        
        NSLog(@"网页加载进度 = %f",_webView.estimatedProgress);
        self.progressView.progress = _webView.estimatedProgress;
        if (_webView.estimatedProgress >= 1.0f) {
            dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.3 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
                self.progressView.progress = 0;
            });
        }
        
    }else if([keyPath isEqualToString:@"title"]
             && object == _webView){
        self.navStr = _webView.title;
//        [_navView changeTitle:UnPackStr(self.navStr)];
    }
}

#pragma mark - Events Handle
//返回上一步
- (void)goBackAction:(id)sender{
    if (_webView.canGoBack) {
        [_webView goBack];
    }else{
        
    }
}
//前往下一步
- (void)goForwardAction:(id)sender{
    [_webView goForward];
}

#pragma mark - WKNavigationDelegate
// 根据WebView对于即将跳转的HTTP请求头信息和相关信息来决定是否跳转
- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {
    //请求头信息
    NSDictionary *allHTTPHeaderFields =  [navigationAction.request allHTTPHeaderFields];
    NSLog(@" UserAgent: %@",allHTTPHeaderFields[@"User-Agent"]);
    decisionHandler(WKNavigationActionPolicyAllow);
}
// 根据客户端受到的服务器响应头以及response相关信息来决定是否可以跳转
- (void)webView:(WKWebView *)webView decidePolicyForNavigationResponse:(WKNavigationResponse *)navigationResponse decisionHandler:(void (^)(WKNavigationResponsePolicy))decisionHandler{
    if ([navigationResponse.response isKindOfClass:[NSHTTPURLResponse class]] && [navigationResponse.response.URL.absoluteString isEqualToString:self.htmlString]) {
        NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *)navigationResponse.response;
        if (httpResponse.statusCode == 304) {
            //自上次请求后，文件还没有修改变化
            //可以加载本地缓存
        }else if (httpResponse.statusCode == 200){
//            [SLMethod userDefaultsSetObject:httpResponse.allHeaderFields[@"Last-Modified"] forKey:@"localLastModified"];
            NSLog(@" httpResponse：%@",httpResponse);
        }
    }
    //允许跳转
    decisionHandler(WKNavigationResponsePolicyAllow);
}
// 页面加载完成之后调用
- (void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation {
    
}
//进程被终止时调用
- (void)webViewWebContentProcessDidTerminate:(WKWebView *)webView{
    //当 WKWebView 总体内存占用过大，页面即将白屏的时候，系统会调用此7u776回调函数，我们在该函数里执行[webView reload](这个时候 webView.URL 取值尚不为 nil）解决白屏问题。在一些高内存消耗的页面可能会频繁刷新当前页面，H5侧也要做相应的适配操作。
    [webView reload];
}
@end