关于异步多线程处理(操作百度翻译API接口)
近期被Task搞到爆炸,本来写的好好的异步操作,提示各种例如“无await异步操作将按照同步来执行”,由于之前我对于多线程基本等于零了解,这次由于工作需要轻轻松松被一个异步多线程困扰了两个周!!!!整整两个周!
简述要求:通过多线程来进行异步处理大数据,举个简单的例子,将数据库中的某一列中文进行中译英,在进行英译中,存回数据库(EF)。
先进行百度翻译API的整理(此处为借鉴大神的操作)
public class Translation
{
public string Src { get; set; }
public string Dst { get; set; }
}
public class TranslationResult
{
//错误码,翻译结果无法正常返回
public string Error_code { get; set; }
public string Error_msg { get; set; }
public string From { get; set; }
public string To { get; set; }
public string Query { get; set; }
//翻译正确,返回的结果
//这里是数组的原因是百度翻译支持多个单词或多段文本的翻译,在发送的字段q中用换行符(\n)分隔
public Translation[] Trans_result { get; set; }
}
public enum Language
{
//百度翻译API官网提供了多种语言,这里只列了几种
auto = 0,
zh = 1,
en = 2,
cht = 3,
}
//对字符串做md5加密
private static string GetMD5WithString(string input)
{
if (input == null)
{
return null;
}
MD5 md5Hash = MD5.Create();
//将输入字符串转换为字节数组并计算哈希数据
byte[] data = md5Hash.ComputeHash(Encoding.UTF8.GetBytes(input));
//创建一个 Stringbuilder 来收集字节并创建字符串
StringBuilder sBuilder = new StringBuilder();
//循环遍历哈希数据的每一个字节并格式化为十六进制字符串
for (int i = 0; i < data.Length; i++)
{
sBuilder.Append(data[i].ToString("x2"));
}
//返回十六进制字符串
return sBuilder.ToString();
}
/// <summary>
/// 调用百度翻译API进行翻译
/// 详情可参考http://api.fanyi.baidu.com/api/trans/product/apidoc
/// </summary>
/// <param name="q">待翻译字符</param>
/// <param name="from">源语言</param>
/// <param name="to">目标语言</param>
/// <returns></returns>
private async Task GetTranslationFromBaiduFanyi(List<CMSPois> Pa , Language from, Language to,string aid,string pd)
{
//可以直接到百度翻译API的官网申请
//一定要去申请,不然程序的翻译功能不能使用
string appId =aid;
string password =pd;
foreach(CMSPois pa in Pa)
{
string q = pa.Description;
if(q==null)
{
continue;
}
if (q == "")
{
continue;
}
string jsonResult = String.Empty;
//源语言
string languageFrom = from.ToString().ToLower();
//目标语言
string languageTo = to.ToString().ToLower();
//随机数
string randomNum = System.DateTime.Now.Millisecond.ToString();
//md5加密
string md5Sign = GetMD5WithString(appId + q + randomNum + password);
//url
string url = String.Format("http://api.fanyi.baidu.com/api/trans/vip/translate?q={0}&from={1}&to={2}&appid={3}&salt={4}&sign={5}",
HttpUtility.UrlEncode(q, Encoding.UTF8),
languageFrom,
languageTo,
appId,
randomNum,
md5Sign
);
WebClient wc = new WebClient();
try
{
jsonResult = wc.DownloadString(url);
}
catch
{
jsonResult = string.Empty;
}
//解析json
JavaScriptSerializer jss = new JavaScriptSerializer();
TranslationResult result = jss.Deserialize<TranslationResult>(jsonResult);
if(result.Trans_result[0].Dst==null)
{
continue;
}
pa.Description = result.Trans_result[0].Dst;
string q1 = pa.Description;
string jsonResult1 = String.Empty;
//源语言
string languageFrom1 = to.ToString().ToLower();
//目标语言
string languageTo1 = from.ToString().ToLower();
//随机数
string randomNum1 = System.DateTime.Now.Millisecond.ToString();
//md5加密
string md5Sign1 = GetMD5WithString(appId + q1 + randomNum1 + password);
//url
string url1 = String.Format("http://api.fanyi.baidu.com/api/trans/vip/translate?q={0}&from={1}&to={2}&appid={3}&salt={4}&sign={5}",
HttpUtility.UrlEncode(q1, Encoding.UTF8),
languageFrom1,
languageTo1,
appId,
randomNum1,
md5Sign1
);
WebClient wc1 = new WebClient();
try
{
jsonResult1 = wc1.DownloadString(url1);
}
catch
{
jsonResult1 = string.Empty;
}
//解析json
JavaScriptSerializer jss1 = new JavaScriptSerializer();
TranslationResult result1 = jss1.Deserialize<TranslationResult>(jsonResult1);
pa.Description = result1.Trans_result[0].Dst;
pa.LastModificationTime = DateTime.Now;
// Debug.WriteLine("poiId: " + pa.Id+ " " + DateTime.Now+" "+appId);
}
//保存数据
PD.SaveChanges();
}
多线程调用方法
在这里你填写多少appId与secretKey就代表你开了多少线程
pois为分页操作,即每个线程平均要处理多少条数据;
最后进行whenall;