cefsharp如何拦截xhr请求获取响应body值？

using CefSharp;
using CefSharp.Handler;

public class CustomRequestHandler : ResourceRequestHandler
{
    protected override bool OnBeforeResourceLoad(IWebBrowser chromiumWebBrowser, IBrowser browser, IFrame frame, IRequest request, IRequestCallback callback)
    {
        // 判断是否为xhr请求
        if (request.ResourceType == ResourceType.Xhr)
        {
            // 拦截xhr请求并获取请求URL
            string requestUrl = request.Url;

            // 在请求完成后获取响应body值
            ResourceHandler resourceHandler = new ResourceHandler();
            resourceHandler.ResourceResponse = new ResourceResponse();
            resourceHandler.ResourceResponse.MimeType = "text/plain"; // 设置响应的MIME类型
            resourceHandler.ResourceResponse.StatusCode = 200; // 设置响应的状态码
            resourceHandler.ResourceResponse.StatusText = "OK"; // 设置响应的状态文本
            resourceHandler.ResourceResponse.ResponseHeaders = new NameValueCollection(); // 设置响应的头部信息
            resourceHandler.ResourceResponse.ResponseHeaders.Add("Access-Control-Allow-Origin", "*"); // 设置允许跨域访问

            // 设置响应的body值
            string responseBody = "This is the response body.";
            resourceHandler.RegisterStream(new MemoryStream(Encoding.UTF8.GetBytes(responseBody)), responseBody.Length);

            // 返回自定义的响应
            callback.Continue();
            return true;
        }

        return base.OnBeforeResourceLoad(chromiumWebBrowser, browser, frame, request, callback);
    }
}

// 在创建浏览器实例时，设置自定义的请求处理器
var settings = new CefSettings();
Cef.Initialize(settings);
var browser = new ChromiumWebBrowser("https://example.com");
browser.RequestHandler = new CustomRequestHandler();