public virtual async Task DownloadFileAsync(VersionFileGetDto versionFileGet)
{
// 分块模式下载文件
// 得到文件流
var fileStream = await _versionFileManager.DownloadFileAsync(
versionFileGet.PlatformType, versionFileGet.Version, versionFileGet.FilePath,
versionFileGet.FileName, versionFileGet.FileVersion);
// 得到文件扩展名
var fileExt = Path.GetExtension(versionFileGet.FileName);
var provider = new FileExtensionContentTypeProvider();
// Http响应标头的文件类型
string memi = provider.Mappings[fileExt];
using (Response.Body)
{
// Http响应标头的文件类型
Response.ContentType = memi;
// 文件大小
byte[] contentBytes = await fileStream.GetAllBytesAsync();
long contentLength = contentBytes.Length;
// 指定响应内容大小
Response.ContentLength = contentLength;
// 单个分块大小 2MB
int bufferSize = 2 * 1024 * 1024;
// 分块总数
int contentByteCount = Math.DivRem(contentBytes.Length, bufferSize, out int modResult);
for (int index = 0; index < contentByteCount; index++)
{
// 当前分页传输字节
byte[] currentTransferBytes = new byte[bufferSize];
if (index == contentByteCount - 1)
{
// 最后一个分块和余数大小一起传输
if (modResult > 0)
{
currentTransferBytes = new byte[bufferSize + modResult];
}
}
// 复制文件流中的当前分块区段
Array.Copy(contentBytes, index * bufferSize, currentTransferBytes, 0, currentTransferBytes.Length);
// 写入响应流
await Response.Body.WriteAsync(currentTransferBytes, 0, currentTransferBytes.Length);
// 清空缓冲区
await Response.Body.FlushAsync();
}
}
}
public virtual Task DownloadFileAsync(VersionFileGetDto versionFileGet)
{
// TODO: 是否需要定义此接口用于 abp-definition-api ?
// overrided implement HttpContext.Response.Body.Write(Stream fileStream)
return(Task.CompletedTask);
}
