如何静音来自UIWebView的音频

// 获取UIWebView的实例
var webView = document.getElementById('your-iframe');

// 监听音频事件
webView.contentWindow.addEventListener('message', function(event) {
  if (event.data.type === 'audio-event') {
    // 音频已经被静音
    alert('音频已经被静音');
  }
});

// 设置UIWebView的代理
@interface YourViewController () <UIWebViewDelegate>

// ...

@end

// 实现UIWebViewDelegate方法
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
  // 监听音频事件
  [[webView.window.contentView superview] addObserver:self
                                             forKeyPath:@"postMessage"
                                               options:NSKeyValueObservingOptionNew
                                               context:nil];

  return YES;
}

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
  if ([keyPath isEqualToString:@"postMessage"]) {
    [self.webView stringByEvaluatingJavaScriptFromString:@"alert('音频已经被静音')"];
  }
}

// 设置WebView的WebViewClient
private WebViewClient mWebViewClient = new WebViewClient() {
    @Override
    public void onPageFinished(WebView view, String url) {
        super.onPageFinished(view, url);

        // 监听音频事件
        if (url.contains("your-audio-src")) {
            new AlertDialog.Builder(YourActivity.this)
                    .setTitle("音频已经被静音")
                    .setMessage("音频已经被静音")
                    .setPositiveButton("确定", null)
                    .show();
        }
    }
};

using System.Runtime.CompilerServices;
using Xamarin.Forms;

namespace YourNamespace
{
    public class CustomWebViewRenderer : WebViewRenderer
    {
        protected override void OnElementChanged(ElementChangedEventArgs<WebView> e)
        {
            base.OnElementChanged(e);

            // 监听音频事件
            if (e.NewElement != null)
            {
                var webView = e.NewElement;
                if (webView.Source.Contains("your-audio-src"))
                {
                    var activity = CrossCurrentActivity.Current.Activity;
                    activity.StartActivity(typeof(YourActivity));
                }
            }
        }
    }
}