WKWebView中 alert不起作用

附上 demo 地址 https://github.com/Liuchunqi3240/demo/tree/master/WKWebView/HTMLStudy

自从学了HTML 之后 再用wkwebview 简直想说 真🐔2️⃣蔡

alert 不做处理的话 在wkwebview上竟然没有反应

是通过document.write()这个函数起作用，而我写的一个alert()没有反应发现的这个问题。

下面说一下解决方法

没事就问问百度
百度告诉我添加一下三个方法就好了

#pragma mark -- WKUIDelegate
// 显示一个按钮。点击后调用completionHandler回调
- (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler{
    
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:message message:nil preferredStyle:UIAlertControllerStyleAlert];
    [alertController addAction:[UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {

    }]];
    [self presentViewController:alertController animated:YES completion:nil];
}

// 显示两个按钮，通过completionHandler回调判断用户点击的确定还是取消按钮
- (void)webView:(WKWebView *)webView runJavaScriptConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(BOOL))completionHandler{
    
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:message message:nil preferredStyle:UIAlertControllerStyleAlert];
    [alertController addAction:[UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
        
    }]];
    [alertController addAction:[UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
        
    }]];
    [self presentViewController:alertController animated:YES completion:nil];
    
}

// 显示一个带有输入框和一个确定按钮的，通过completionHandler回调用户输入的内容
- (void)webView:(WKWebView *)webView runJavaScriptTextInputPanelWithPrompt:(NSString *)prompt defaultText:(NSString *)defaultText initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(NSString * _Nullable))completionHandler{
    
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"" message:nil preferredStyle:UIAlertControllerStyleAlert];
    [alertController addTextFieldWithConfigurationHandler:^(UITextField * _Nonnull textField) {
        
    }];
    [alertController addAction:[UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
        
        completionHandler(alertController.textFields.lastObject.text);
    }]];
    [self presentViewController:alertController animated:YES completion:nil];
}

---

然而事情并没有那么简单

直接给我扔出来一个错误，还一脸蒙蔽

webView:runJavaScriptAlertPanelWithMessage:initiatedByFrame:completionHandler:] was not called'、

然后就闪退了，你们抄袭能不能认真点，都不好用了 你们还放上去

正确的做法应该是这样子的

当然首先你要设置一下wkwebview的代理

 self.webView.uiDelegate = self

// MARK: - WKUIDelegate
extension WKWebViewController: WKUIDelegate{
    // show js alert
    func webView(_ webView: WKWebView, runJavaScriptAlertPanelWithMessage message: String, initiatedByFrame frame: WKFrameInfo, completionHandler: @escaping () -> Void) {
        let alert = UIAlertController.init(title: message, message: nil, preferredStyle: .alert)
        let action = UIAlertAction.init(title: "确定", style: .default) { (action) in
            completionHandler()
        }
        alert.addAction(action)
        
        
        
        self.present(alert, animated: true, completion: nil)
    }
    // show js commfirm
    func webView(_ webView: WKWebView, runJavaScriptConfirmPanelWithMessage message: String, initiatedByFrame frame: WKFrameInfo, completionHandler: @escaping (Bool) -> Void) {
        let alert = UIAlertController.init(title: message, message: nil, preferredStyle: .alert)
        let cancelAction = UIAlertAction.init(title: "取消", style: .cancel) { (action) in
            completionHandler(false)
        }
        alert.addAction(cancelAction)
        
        let sureAction = UIAlertAction.init(title: "确定", style: .default) { (action) in
            completionHandler(true)
        }
        alert.addAction(sureAction)
        
        self.present(alert, animated: true, completion: nil)
    }
 
    // show js Prompt
    func webView(_ webView: WKWebView, runJavaScriptTextInputPanelWithPrompt prompt: String, defaultText: String?, initiatedByFrame frame: WKFrameInfo, completionHandler: @escaping (String?) -> Void) {
        let alert = UIAlertController.init(title: "提示", message: prompt, preferredStyle: .alert)
        
        alert.addTextField { (texfiled) in
            texfiled.placeholder = defaultText
        }
        
        let sureAction = UIAlertAction.init(title: "确定", style: .default) { (action) in
            completionHandler(alert.textFields?.last?.text ?? "")
        }
        alert.addAction(sureAction)
        
        self.present(alert, animated: true, completion: nil)
    }
    
    
}