// 功能：获取下载文件的大小
// 参数：url - 网络URL地址
// nFileSize - 输出文件的大小
// 返回值：返回true表示得到了文件的大小，URL地址有效; 返回false表示无法得到文件的信息
// 说明：这个接口是阻塞模式的，请不要在主线程调用
static public bool GetDownFileSize(string url, out int nOutFileSize, long nRandSeed = 0)
{
nOutFileSize = 0;
CHttp http = new CHttp(nRandSeed);
string szServerIP = string.Empty, szObj = string.Empty;
int nPort = 80;
http.ParseURL(url, ref szServerIP, ref szObj, ref nPort);
string szAnswer = string.Empty;
if (!http.QueryFile(ref szAnswer, szServerIP, nPort, szObj, 0, 1, false))
{
http.Close();
return(false);
}
int nDownSize = 0, nFileSize = 0;
if (!http.AnlyseFileLengthFromAnswer(szAnswer, ref nDownSize, ref nFileSize))
{
http.Close();
return(false);
}
http.Close();
nOutFileSize = nFileSize;
return(true);
}
// 功能：下载整个文件
// 说明：这个接口是阻塞模式的，请不要在主线程调用
static public bool DownFile(string url, out byte[] szFileData, int nDownOffset = 0, int nNeedDownSize = 0, long nRandSeed = 0, LPOnReceiveDownFile lpReceiveFunc = null)
{
szFileData = null;
CHttp http = new CHttp(nRandSeed);
string szServerIP = string.Empty, szObj = string.Empty;
int nPort = 80;
http.ParseURL(url, ref szServerIP, ref szObj, ref nPort);
string szAnswer = string.Empty;
if (!http.QueryFile(ref szAnswer, szServerIP, nPort, szObj, nDownOffset, nNeedDownSize, nNeedDownSize <= 0))
{
http.Close();
return(false);
}
int nDownSize = 0, nFileSize = 0;
if (!http.AnlyseFileLengthFromAnswer(szAnswer, ref nDownSize, ref nFileSize))
{
http.Close();
return(false);
}
nDownSize = nFileSize;
byte[] szTempBuf = null;
szFileData = new byte[nFileSize];
int nRecTotal = 0;
int nRecLen = 0;
int nOffset = 0;
while (nRecTotal < nDownSize)
{
nRecLen = http.FastReceiveMax(ref szTempBuf, ref nOffset);
// 写入文件吧
if (nRecLen > 0)
{
if (lpReceiveFunc != null)
{
lpReceiveFunc(nRecLen);
}
Array.Copy(szTempBuf, nOffset, szFileData, nRecTotal, nRecLen);
nRecTotal += nRecLen;
}
else
{
break;
}
}
http.Close();
return(nRecTotal == nDownSize);
}
// 功能：下载文件，并将下载的文件保存到本地
// 参数：url - 网络URL的地址
// szLocalPathName - 本地保存地址
// 说明：这个接口是阻塞模式的，请不要在主线程调用
static public bool DownFile(string url, string szLocalPathName, int nNeedDownOffset, int nNeedDownSize, long nRandSeed = 0, LPOnReceiveDownFile lpReceiveFunc = null)
{
CHttp http = new CHttp(nRandSeed);
string szServerIP = string.Empty, szObj = string.Empty;
int nPort = 80;
http.ParseURL(url, ref szServerIP, ref szObj, ref nPort);
string szAnswer = string.Empty;
if (!http.QueryFile(ref szAnswer, szServerIP, nPort, szObj, nNeedDownOffset, nNeedDownSize, nNeedDownSize <= 0))
{
http.Close();
return(false);
}
int nDownSize = 0, nFileSize = 0;
if (!http.AnlyseFileLengthFromAnswer(szAnswer, ref nDownSize, ref nFileSize))
{
http.Close();
return(false);
}
if (nNeedDownSize <= 0)
{
nDownSize = nFileSize; // 这是全部下载
}
// 打开本地文件
if (File.Exists(szLocalPathName))
{
File.Delete(szLocalPathName);
}
FileStream pFile = new FileStream(szLocalPathName, FileMode.CreateNew, FileAccess.Write);
// 开始下载吧
byte[] szTempBuf = null;
int nRecTotal = 0;
int nRecLen = 0;
int nOffset = 0;
while (nRecTotal < nDownSize)
{
nRecLen = http.FastReceiveMax(ref szTempBuf, ref nOffset);
// 写入文件吧
if (nRecLen > 0)
{
if (lpReceiveFunc != null)
{
lpReceiveFunc(nRecLen);
}
nRecTotal += nRecLen;
pFile.Write(szTempBuf, nOffset, nRecLen);
}
else
{
break;
}
}
http.Close();
pFile.Close();
return(nRecTotal == nDownSize);
}