问题描述
研究了这个话题并尝试实现不同的解决方案，但我无法解决它。 我有一个函数 plotmyChartAsync() 从谷歌趋势中获取值。 在控制台应用程序中使用此功能工作正常，我得到了理想的结果。 但是当我尝试使用 Windows 窗体中的按钮执行此功能时，它总是失败。有了这个“HttpResponseMessage secondResponse = await clientUsed.GetAsync(secondRequestStr);”我总是从 API 得到 429 失败。这意味着我要发送许多请求。我怎样才能避免这种情况？
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Net;
using System.Net.Http;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System.Globalization;
using System.Threading;
namespace GoogleTrendsAnalysis
{
public partial class Form1 : Form
{
private SemaphoreSlim _mutex = new SemaphoreSlim(1);
public Form1()
{
InitializeComponent();
}
public async Task plotmyChartAsync()
{
await _mutex.WaitAsync();
try
{
const string searchKeyWord = "bmw";
const string firstTimePeriodString = "2021-01-10T00";
const string secondTimePeriodString = "+2021-01-15T00";
const string httprequestStr = "https://trends.google.de/trends/api/explore?hl=de&tz=-60&req=%7B%22comparisonItem%22:%5B%7B%22keyword%22:%22" + searchKeyWord + "%22,%22geo%22:%22DE%22,%22time%22:%22" + firstTimePeriodString + secondTimePeriodString + "%22%7D%5D,%22category%22:0,%22property%22:%22%22%7D&tz=-60";
CookieContainer cookies = new CookieContainer();
httpclienthandler handler = new httpclienthandler();
handler.CookieContainer = cookies;
HttpClient client = new HttpClient(handler);
HttpResponseMessage response = await client.GetAsync(httprequestStr,HttpCompletionoption.ResponseHeadersRead);
Uri uri = new Uri(httprequestStr);
Console.WriteLine(cookies.GetCookies(uri));
IEnumerable<Cookie> responseCookies = cookies.GetCookies(uri).Cast<Cookie>();
Console.WriteLine(responseCookies.First());
string cookieused = responseCookies.First().Name + "=" + responseCookies.First().Value;
client.CancelPendingRequests();
client.dispose();
handler.dispose();
using (var clientUsed = new HttpClient())
{
clientUsed.BaseAddress = new Uri("https://trends.google.de/trends/api/");
clientUsed.DefaultRequestHeaders.Add("cookie",cookieused);
Console.WriteLine(clientUsed.DefaultRequestHeaders);
HttpResponseMessage responseUsed = await clientUsed.GetAsync(httprequestStr);
responseUsed.EnsureSuccessstatusCode();
Console.WriteLine(responseUsed);
if (responseUsed.IsSuccessstatusCode)
{
string result = responseUsed.Content.ReadAsstringAsync().Result;
result = result.Substring(4,result.Length - 4);
Console.WriteLine("Result: " + result);
dynamic data = JObject.Parse(result);
Console.WriteLine("TOKEN: " + data.widgets[0]["token"]);
string myToken = data.widgets[0]["token"];
string secondRequestStr = "https://trends.google.de/trends/api/widgetdata/multiline?hl=de&tz=-60&req=%7B%22time%22:%22" + firstTimePeriodString + "%5C%5C:00%5C%5C:00" + secondTimePeriodString + "%5C%5C:00%5C%5C:00%22,%22resolution%22:%22HOUR%22,%22locale%22:%22de%22,%22comparisonItem%22:%5B%7B%22geo%22:%7B%22country%22:%22DE%22%7D,%22complexKeywordsRestriction%22:%7B%22keyword%22:%5B%7B%22type%22:%22broAD%22,%22value%22:%22" + searchKeyWord + "%22%7D%5D%7D%7D%5D,%22requestOptions%22:%7B%22property%22:%22%22,%22backend%22:%22CM%22,%22category%22:0%7D%7D&token=" + myToken + "&tz=-60";
HttpResponseMessage secondResponse = await clientUsed.GetAsync(secondRequestStr);
secondResponse.EnsureSuccessstatusCode();
string secondResult = secondResponse.Content.ReadAsstringAsync().Result;
List<DateTime> dateTimes = new List<DateTime>();
List<double> values = new List<double>();
secondResult = secondResult.Substring(5,secondResult.Length - 5);
dynamic secondData = JObject.Parse(secondResult);
foreach (var t in secondData)
{
foreach (var x in t)
{
foreach (var s in x.timelineData)
{
bool ifhasDataStr = s.hasData[0];
if (ifhasDataStr == true)
{
string formattedValueStr = s.formattedValue[0];
string formattedTimeStr = s.formattedTime;
double myValue = Convert.Todouble(formattedValueStr);
formattedTimeStr = formattedTimeStr.Replace(" um "," ");
DateTime dt = DateTime.ParseExact(formattedTimeStr,"dd.MM.yyyy HH:mm",CultureInfo.InvariantCulture);
dateTimes.Add(dt);
values.Add(myValue);
Console.WriteLine("Die ZEIT: " + formattedTimeStr + " / DER WERT: " + myValue);
}
}
}
}
double numberOfPeriods = dateTimes.Count;
double[] valuesArr = values.ToArray();
double[] xs = new double[valuesArr.Length];
for (int i = 0; i < valuesArr.Length; i++)
{
xs[i] = dateTimes[i].ToOADate();
}
formsPlot1.Reset();
formsPlot1.plt.PlotScatter(xs,valuesArr);
formsPlot1.plt.Ticks(dateTimeX: true);
formsPlot1.Render();
}
}
}
finally
{
_mutex.Release();
}
}
protected async void button1_Click(object sender,EventArgs e)
{
await plotmyChartAsync();
}
}
}
解决方法
经过研究，我发现问题出在 cookie... 下面是上面代码需要做的调整...
var baseAddress = new Uri("https://trends.google.de/trends/api/");
using (var firstHandler = new HttpClientHandler() { UseCookies = false })
using (var clientUsed = new HttpClient(firstHandler) { BaseAddress = baseAddress })
{
clientUsed.BaseAddress = baseAddress;
clientUsed.DefaultRequestHeaders.Accept.Clear();
//clientUsed.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
//clientUsed.DefaultRequestHeaders.Add("cookie",cookieused);
var firstRequest = new HttpRequestMessage(HttpMethod.Get,httprequestStr);
firstRequest.Headers.Add("cookie",cookieused);
Console.WriteLine(httprequestStr);
HttpResponseMessage responseUsed = await clientUsed.SendAsync(firstRequest);
Console.WriteLine(responseUsed);
string result = responseUsed.Content.ReadAsStringAsync().Result;
Console.WriteLine(result);