/// <summary>
/// 启动下载
/// </summary>
/// <param name="sUrl">下载链接</param>
/// <param name="sPath">路径文件名</param>
/// <param name="data">中间传递的数据</param>
/// <param name="UpdateFunc">进度更新</param>
/// <param name="CompleteFunc">下载结束</param>
/// <param name="ErrFunc">错误</param>
/// <param name="Timeout">超时</param>
/// <param name="UserAgent"></param>
/// <param name="ContentType"></param>
public static Task <object> StartAsync(string sUrl,
string sPath,
object data = null,
UpdateDownloadNotify UpdateFunc = null,
CompleteDownloadNotify CompleteFunc = null,
ErrDownloadNotify ErrFunc = null,
int RetryNum = 0,
int Timeout = 5 * 1000,
string UserAgent = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Safari/537.36",
string ContentType = "application/x-www-form-urlencoded; charset=UTF-8",
bool bOnlyGetSize = false,
bool bAppendFile = false,
HttpHelper.ProxyInfo Proxy = null)
{
return(Task.Run(() =>
{
UpdateDownloadNotify UpdateMothed = UpdateFunc == null ? null : new UpdateDownloadNotify(UpdateFunc);
CompleteDownloadNotify CompleteMothed = CompleteFunc == null ? null : new CompleteDownloadNotify(CompleteFunc);
ErrDownloadNotify ErrMothed = ErrFunc == null ? null : new ErrDownloadNotify(ErrFunc);
long lAlreadyDownloadSize = 0;
long lTotalSize = 0;
long lIncreSize = 0;
if (RetryNum > 50)
{
RetryNum = 50;
}
RETRY_ENTRY:
try
{
bool bRet = false;
ServicePointManager.Expect100Continue = false;
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(sUrl);
request.Method = "GET";
request.ContentType = ContentType;
request.Timeout = Timeout;
//request.KeepAlive = true;
request.UserAgent = UserAgent;
request.Proxy = null;
if (Proxy != null && Proxy.Host.IsNotBlank() && Proxy.Port >= 0)
{
WebProxy myProxy = new WebProxy(Proxy.Host, Proxy.Port);
if (Proxy.Username.IsNotBlank() && Proxy.Password.IsNotBlank())
{
myProxy.Credentials = new NetworkCredential(Proxy.Username, Proxy.Password);
}
request.Proxy = myProxy;
request.Credentials = CredentialCache.DefaultNetworkCredentials;
}
//开始请求
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
lTotalSize = response.ContentLength;
if (bOnlyGetSize)
{
return (object)lTotalSize;
}
//创建目录
string pDir = Path.GetDirectoryName(sPath);
PathHelper.Mkdirs(pDir);
if (File.Exists(sPath) && !bAppendFile)
{
File.Delete(sPath);
}
//打开文件
Stream myResponseStream = response.GetResponseStream();
//一分钟超时
myResponseStream.ReadTimeout = 60000;
System.IO.Stream pFD = new System.IO.FileStream(sPath, bAppendFile ? System.IO.FileMode.Append : System.IO.FileMode.Create);
//如果走到这里的话，就不能重试了，要不如进度会出错
RetryNum = 0;
byte[] buf = new byte[1024];
int size = 0;
while ((size = myResponseStream.Read(buf, 0, (int)buf.Length)) > 0)
{
lIncreSize = size;
lAlreadyDownloadSize += size;
pFD.Write(buf, 0, size);
if (UpdateFunc != null)
{
if (!UpdateMothed(lTotalSize, lAlreadyDownloadSize, lIncreSize, data))
{
goto RETURN_POINT;
}
}
}
if (CompleteMothed != null)
{
CompleteMothed(lTotalSize, data);
}
bRet = true;
RETURN_POINT:
pFD.Close();
myResponseStream.Close();
return bRet;
}
catch (System.Exception e)
{
if (RetryNum > 0)
{
RetryNum--;
goto RETRY_ENTRY;
}
if (ErrMothed != null)
{
ErrMothed(lTotalSize, lAlreadyDownloadSize, e.Message, data);
}
if (bOnlyGetSize)
{
return (object)0;
}
return (object)false;
}
}));
}