/// <summary>
/// 下载模组
/// </summary>
public void DownloadMod(DownloadStatus status)
{
DownloadModPrivate(status, 1);
}
//内部方法，用于下载失败时递归重试
private void DownloadModPrivate(DownloadStatus status, int tryTime)
{
//检查下载失败
if (tryTime > TryTime)
{
DownFailed?.Invoke(this, status);
return;
}
string urlStr = string.Format(BASE_DOWNLOAD_URL, status.ProjectId, status.FileId);
//检查网址正确性
if (!Uri.TryCreate(urlStr, UriKind.Absolute, out Uri url))
{
throw new FormatException("Url格式错误");
}
var req = (HttpWebRequest)WebRequest.Create(url);
HttpWebResponse rep;
//超时检查
try
{
rep = (HttpWebResponse)req.GetResponse();
}
catch (WebException)
{
//超时重试
DownloadModPrivate(status, tryTime + 1);
return;
}
//文件总大小
long totalBytes = rep.ContentLength;
//已经下载的大小
long downloaded = 0;
//缓存
byte[] buffer = new byte[1024];
//当前时间计算反馈周期用
DateTime startTime = DateTime.Now;
DateTime endTime;
//下载量数组，用于计算速度
Queue <double> insSpeeds = new Queue <double>(20);
for (int i = 0; i < 20; i++)
{
insSpeeds.Enqueue(0.0);
}
//下载速度
int speed = 0;
//获取文件名
string fileName = rep.ResponseUri.Segments.Last();
//获取文件地址
string modPath = Path.Combine(DirectoryPath, "mods", fileName);
//临时下载文件地址（下载完成重命名，防止下载中断导致文件损坏）
string tmpPath = modPath + ".cfdownload";
//保存参数
status.TotalBytes = totalBytes;
status.FileName = fileName;
status.Speed = 0;
status.DownloadedBytes = 0;
//下载开始反馈
status.IsBegin = true;
DownBegin?.Invoke(this, status);
if (File.Exists(modPath))
{
rep.Close();
status.DownloadedBytes = status.TotalBytes;
DownComplete?.Invoke(this, status);
return;
}
#region 载具体实现
//创建文件夹
Directory.CreateDirectory(Path.Combine(DirectoryPath, "mods"));
//保存流
using (FileStream fsSave = new FileStream(tmpPath,
FileMode.Create, FileAccess.ReadWrite, FileShare.None))
{
//下载流
using (Stream rsDown = rep.GetResponseStream())
{
//单位时间内下载量
int periodBytes = 0;
int r = 1;
//循环读流
while (r > 0)
{
//计算速度
endTime = DateTime.Now;
TimeSpan span = endTime - startTime;
//速度计算周期50ms
if (span > TimeSpan.FromMilliseconds(50))
{
//瞬时速度
double insSpeed = periodBytes / span.TotalSeconds / 1024;
//重置计算
periodBytes = 0;
startTime = DateTime.Now;
//计算平均速度
insSpeeds.Dequeue();
insSpeeds.Enqueue(insSpeed);
speed = (int)insSpeeds.Average();
}
//反馈进度
status.DownloadedBytes = downloaded;
status.Speed = speed;
try
{
r = rsDown.Read(buffer, 0, 1024); //读流
fsSave.Write(buffer, 0, r); //存流
}
catch (IOException)
{
fsSave.Close();
rsDown.Close();
DownloadModPrivate(status, tryTime + 1);
return;
}
//保存进度
downloaded += r;
periodBytes += r;
}
}
}
//下载完成，重命名文件（防止下载中断错误）
if (File.Exists(modPath))
{
File.Delete(modPath);
}
File.Move(tmpPath, modPath);
//下载完成反馈
Thread.Sleep(100);
DownComplete?.Invoke(this, status);
#endregion
}
public void Begin(DownloadStatus status)
{
txtName.Text = status.FileName;
}
