private void ThreadableResumeDownload(string url)
{
if (_isFinished)
{
Error = new Exception("Before ThreadableResumeDownload Error!");
return;
}
System.IO.FileStream downloadFileStream;
//打开上次下载的文件或新建文件
long lStartPos = 0;
if (_useContinue && System.IO.File.Exists(TmpDownloadPath))
{
downloadFileStream = System.IO.File.OpenWrite(TmpDownloadPath);
lStartPos = downloadFileStream.Length;
downloadFileStream.Seek(lStartPos, System.IO.SeekOrigin.Current); //移动文件流中的当前指针
Log("Resume.... from {0}", lStartPos);
//CDebug.LogConsole_MultiThread("Resume.... from {0}", lStartPos);
}
else
{
downloadFileStream = new System.IO.FileStream(TmpDownloadPath, System.IO.FileMode.OpenOrCreate);
lStartPos = 0;
}
Requester = new HttpRequester(Url, downloadFileStream, BufferSize);
if (lStartPos > 0)
{
Requester.SetRequestRange(lStartPos);
}
Requester.BeforeReadAsyncHook = _requesterAsyncHook;
Requester.SetFinishCallback(OnRequestFinish);
Requester.SetStreamCallback((req) =>
{
if (_stepCallback != null)
{
_stepCallback(this);
}
});
Requester.Start();
}
private void OnRequestFinish(HttpRequester req)
{
try
{
req.Dispose(); // 释放写入的Stream...进行移动操作
Error = req.Error;
if (IsError)
{
Log("下载过程中出现错误:" + Error.ToString());
// 如果非断点续传模式，错误删掉临时文件
if (!_useContinue)
{
if (File.Exists(TmpDownloadPath))
{
File.Delete(TmpDownloadPath); // delete temporary file
}
}
}
else
{
if (File.Exists(_saveFullPath))
{
File.Delete(_saveFullPath);
}
File.Move(TmpDownloadPath, _saveFullPath);
}
}
catch (Exception e)
{
Error = e;
}
IsFinished = true;
}
