在本教程中,我们将介绍如何实现 Web 呈现器的异步方法。您只需要将 HTML 内容发送到 SubmitPDFFromHTMLTask 或 SubmitImageFromHTMLTask API 方法即可接收任务标识符作为响应。还有SubmitPDFFromUrlTask和SubmitImageFromUrlTask方法,用于从公共Web Uri呈现PDF或图像。

收到任务标识符后,您需要通过调用 GetRenderingTaskStatus 方法来检查任务状态。只要任务状态等于“Waiting”,您需要在几秒钟延迟后调用相同的方法。一旦您从 GetRenderingTaskStatus 方法收到“Completed”,您就可以调用 DownloadResult 方法来下载最终文件。可以使用下面的 C# 实现。

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async Task<string> SubmitPDFFromHTMLTask(string htmlContent, string uri, string rapidApiKey)
{
    using (HttpClient httpClient = new HttpClient())
    {
        using (MultipartFormDataContent form = new MultipartFormDataContent())
        {
            form.Headers.Add("X-RapidAPI-Key", rapidApiKey);
            form.Add(new StringContent(uri), "uri");
            form.Add(new StringContent("false"), "useCompression");
            form.Add(new StringContent("Home Page"), "pageLabel");
            form.Add(new StringContent("Initial Capture"), "messageLabel");
            form.Add(new StringContent("768"), "browserHeight");
            form.Add(new StringContent("1024"), "browserWidth");
            form.Add(new StringContent(htmlContent), "htmlContent");
            using (var response = await httpClient.PostAsync("https://web-renderer.p.rapidapi.com/SubmitPDFFromHTMLTask", form))
            {
                response.EnsureSuccessStatusCode();
                return await response.Content.ReadAsStringAsync();
            }
        }
    }
}

async Task<string> GetRenderingTaskStatus(string taskId, string rapidApiKey)
{
    using (HttpClient httpClient = new HttpClient())
    {
        httpClient.DefaultRequestHeaders.Add("X-RapidAPI-Key", rapidApiKey);

        using (var response = await httpClient.GetAsync($"https://web-renderer.p.rapidapi.com/GetRenderingTaskStatus?taskId={taskId}"))
        {
            response.EnsureSuccessStatusCode();
            return await response.Content.ReadAsStringAsync();
        }
    }
}

async Task<byte[]> DownloadResult(string taskId, string rapidApiKey)
{
    using (HttpClient httpClient = new HttpClient())
    {
        httpClient.DefaultRequestHeaders.Add("X-RapidAPI-Key", rapidApiKey);

        using (var response = await httpClient.GetAsync($"https://web-renderer.p.rapidapi.com/DownloadResult?taskId={taskId}"))
        {
            response.EnsureSuccessStatusCode();
            return await response.Content.ReadAsByteArrayAsync();
        }
    }
}

var rapidApiKey = "<YOUR RAPIDAPI KEY HERE>";
var htmlContent = "<HTML CONTENT TO RENDER>";
var uriOfHtmlContent = "https://www.google.com?hl=en";
var taskId = await SubmitPDFFromHTMLTask(htmlContent, uriOfHtmlContent, rapidApiKey);
var retryCount = 0;
while (retryCount < 100)
{
    retryCount++;
    await Task.Delay(5000);
    var status = await GetRenderingTaskStatus(taskId, rapidApiKey);
    if (status == "Completed")
    {
        var fileBytes = await DownloadResult(taskId, rapidApiKey);
        await File.WriteAllBytesAsync("html_from_html.pdf", fileBytes);
        break;
    }
    else if (status == "Waiting")
    {
        continue;
    }
    else if (status == "Failed")
    {
        throw new Exception("Cannot convert file");
    }
    else
    {
        throw new Exception("Invalid status");
    }
}