WKWebView免登陆，配置cookie-白红宇

需求：纯webapp第一次登录记住账号密码，退出app，下次启动时候免登录

第一步：

创建wkwebview对象时，选择自定义配置加载网页是携带cookie。如果本地存有上次登录保留的cookie，那么直接将cookie配置到wkwebview，可以在加载后面的页面是自动携带cookie，本地没有缓存cookie，则跳转登录页.

- (WKWebView *)webView{ if (_webView == nil) {        WKUserContentController *userContrntController = [[WKUserContentController alloc] init];        WKWebViewConfiguration *config = [[WKWebViewConfiguration alloc] init];        config.userContentController = userContrntController;        WKProcessPool *processpool = [[WKProcessPool alloc] init];        config.processPool = processpool;                WKUserScript *cookieScript = [[WKUserScript alloc] initWithSource:[self cookieJavaScriptString] injectionTime:WKUserScriptInjectionTimeAtDocumentStart forMainFrameOnly:YES];        [userContrntController addUserScript:cookieScript];          _webView = [[WKWebView alloc] initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height-kNavigationBarHeight) configuration:config];  _webView.navigationDelegate = self;        _webView.UIDelegate = self;  _webView.allowsBackForwardNavigationGestures = YES; }  return _webView;}复制代码

第二步：

获取本地cookie，cookie本地持久化用网页urlHost作为键值，保证需要同一个cookie的网页通过urlHost获取对应cookie，从本地取出cookie的内容

//配置config，获取cookieString- (NSString *)cookieJavaScriptString{    NSMutableString *cookieString = [[NSMutableString alloc] init];    NSUserDefaults *userDefault = [NSUserDefaults standardUserDefaults];    NSDictionary *cookieDic = [userDefault objectForKey:self.urlHost];    for (NSString *key in cookieDic) {        NSHTTPCookie *cookie = [[NSHTTPCookie alloc] initWithProperties:[cookieDic objectForKey:key]];        NSString *excuteJSString = [NSString stringWithFormat:@"document.cookie='%@=%@';",cookie.name,cookie.value];        [cookieString appendString:excuteJSString];    }    return cookieString;}复制代码

第三步：

在网页跳转之前，向服务器发送请求之前先判断是否携带cookie，如果没有携带cookie，取消跳转，手动添加cookie在跳

//发送请求之前，决定是否跳转- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(nonnull WKNavigationAction *)navigationAction decisionHandler:(nonnull void (^)(WKNavigationActionPolicy))decisionHandler{    self.urlHost = navigationAction.request.URL.host;    if (self.urlHost) {        if (!navigationAction.request.allHTTPHeaderFields[@"Cookie"]) {            decisionHandler(WKNavigationActionPolicyCancel);            [self loadRequestWithString:navigationAction.request.URL];        } else {            decisionHandler(WKNavigationActionPolicyAllow);        }    } else {        decisionHandler(WKNavigationActionPolicyAllow);    }}复制代码

//手动添加cookie- (void)loadRequestWithString:(NSURL *)url{    NSMutableString *cookieValue = [NSMutableString string];    NSUserDefaults *userDefault = [NSUserDefaults standardUserDefaults];    NSDictionary *cookieDic = nil;    if (self.urlHost) {        cookieDic = [userDefault objectForKey:self.urlHost];    }        for (NSString *key in cookieDic) {        NSHTTPCookie *cookie = [[NSHTTPCookie alloc] initWithProperties:[cookieDic objectForKey:key]];        NSString *appendString = [NSString stringWithFormat:@"%@=%@",cookie.name,cookie.value];        [cookieValue appendString:appendString];    }    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];    [request addValue:cookieValue forHTTPHeaderField:@"Cookie"];    [self.webView loadRequest:request];}复制代码

第四步：

保存cookie，第一次或第cookie失效的时候需要登录，成功之后将网页请求的cookie保存在本地，下次加载需要使用

//接收到响应后，决定是否跳转- (void)webView:(WKWebView *)webView decidePolicyForNavigationResponse:(nonnull WKNavigationResponse *)navigationResponse decisionHandler:(nonnull void (^)(WKNavigationResponsePolicy))decisionHandler{    //将获取的cookie本地化    NSUserDefaults *userDefault = [NSUserDefaults standardUserDefaults];    NSMutableDictionary *cookieDic = [[NSMutableDictionary alloc] initWithDictionary:[userDefault objectForKey:self.urlHost]];    NSHTTPURLResponse *response = (NSHTTPURLResponse *)navigationResponse.response;    NSArray *cookies = [NSHTTPCookie cookiesWithResponseHeaderFields:[response allHeaderFields] forURL:response.URL];    for (NSHTTPCookie *cookie in cookies) {        [cookieDic setObject:[cookie properties] forKey:cookie.name];    }    [userDefault setObject:cookieDic forKey:self.urlHost];    decisionHandler(WKNavigationResponsePolicyAllow);}复制代码

注意：我这里的slef.urlHost默认是请求h5的域名

补充：最近测试的时候发现这么方法有点bug，如果cookie进场丢失，程序先是进入一个空白页面，时间很短暂，难以察觉，所以返回的时候会出现空白页，而且有时候一直返回不了，一直停留在空白页上。

我的解决方法是在

-(void)webView:(WKWebView *)webView decidePolicyForNavigationResponse:(nonnull WKNavigationResponse *)navigationResponse decisionHandler:(nonnull void (^)(WKNavigationResponsePolicy))decisionHandler复制代码

这个方法里添加一个判断操作，如果是返回的时候直接

decisionHandler(WKNavigationResponsePolicyAllow);复制代码

所以要监听返回按钮的操作事件