WKWebView 笔记

WKWebView JS 交互

客户端中加入以下代码 可以监听JS->OC

WKWebViewConfiguration *configuration = [[WKWebViewConfiguration alloc] init];
[configuration.userContentController addScriptMessageHandler:self name:@"abc"];

 //发送的信息仅支持字符串
window.webkit.messageHandlers.abc.postMessage("你好") ;

当在页面中调用 以上JS代码后 在 delegate 中接受到数据

-(void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message {
    if ([message.name isEqualToString:@"abc"]) {
        NSLog(@" %@",message.body);
    }
}

  //移除Handler
    [self.webView.configuration.userContentController removeScriptMessageHandlerForName:@"abc"];

重点
在这里的Controller 退出的时候dealloc ,并不会执行。 WKScriptMessageHandler,会有内存泄漏的Bug，
目前的解决方式 新建一个对象实现上述代理。

@interface WeakMessageHandler : NSObject <WKScriptMessageHandler>

@property (nullable, nonatomic, weak)id <WKScriptMessageHandler> delegate; //重点

-(instancetype)initWithMessageHandler:(id<WKScriptMessageHandler>) delegate ;
@end

-(instancetype)initWithMessageHandler:(id<WKScriptMessageHandler>)delegate {
    if (self = [super init]) {
        _delegate = delegate;
    }
    return self;
}

-(void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message {
    if (self.delegate && [self.delegate respondsToSelector:@selector(userContentController:didReceiveScriptMessage:)]) {
        [self.delegate userContentController:userContentController didReceiveScriptMessage:message];
    }
}

即可解决内存泄漏的问题

OC->JS

  [self.webView evaluateJavaScript:@"方法" completionHandler:nil]