MultipartFormDataContent GetMultipartFormDataContent2(IEnumerable <IUploadFileSource> uploadFiles)
{
var multipartFormDataContent = new MultipartFormDataContent();
int index = 0;
foreach (var item in uploadFiles)
{
if (item.HasValue() && item.Available)
{
var uploadFile = item;
var stream = uploadFile.OpenRead();
void ThrowUnsupportedUploadFileMediaType() // 未知的上传媒体类型
{
stream?.Dispose();
multipartFormDataContent.Dispose();
// ↑ 释放未压缩的文件流 与 总内容(MultipartFormDataContent) 当前文件源不释放
var msg = $"Unsupported Upload File MediaType, filePath: {uploadFile.FilePath}, index: {index}";
logger.LogError(msg);
throw new ApiResponseCodeException(
ApiResponseCode.UnsupportedUploadFileMediaType, msg);
}
var needHandle = true;
switch (uploadFile.UploadFileType) // 上传文件类型
{
case UploadFileType.Image: // 图片
if (uploadFile.IsCompressed) // 文件源已压缩过
{
if (string.IsNullOrEmpty(uploadFile.MIME)) // 无MIME，则检测
{
if (FileFormat.IsImage(stream, out var format))
{
if (format.IsAllow()) // 属于允许的格式，则不处理
{
uploadFile.MIME = format.GetMIME();
needHandle = false;
}
}
}
else if (FileFormat.AllowImageMediaTypeNames.Contains(uploadFile.MIME))
{
// 有MIME值，且在允许的范围内，则不处理
needHandle = false;
}
}
break;
//case UploadFileType.Voice: // 音频
// break;
//case UploadFileType.Video: // 视频
// break;
default:
throw new ArgumentOutOfRangeException(nameof(uploadFile.UploadFileType), uploadFile.UploadFileType, null);
}
if (needHandle)
{
var result = helper.TryHandleUploadFile(stream, uploadFile.UploadFileType);
if (!result.HasValue) // 处理失败
{
ThrowUnsupportedUploadFileMediaType();
}
else
{
stream.Dispose();
uploadFile.Dispose();
// ↑ 释放未压缩的文件流 与 文件源
uploadFile = new UploadFileSource
{
FilePath = result.Value.filePath,
MIME = result.Value.mime,
IsCompressed = true,
IsCache = true,
UploadFileType = uploadFile.UploadFileType,
};
stream = uploadFile.OpenRead();
// 生成新的文件源 并 重新打开文件流
}
}
var content = new UploadFileContent(uploadFile, stream);
if (string.IsNullOrWhiteSpace(uploadFile.FilePath))
{
multipartFormDataContent.Add(content, "file");
}
else
{
var fileName = Path.GetFileName(uploadFile.FilePath);
multipartFormDataContent.Add(content, "file", fileName);
}
}
index++;
}
if (!multipartFormDataContent.Any())
{
throw new ApiResponseCodeException(ApiResponseCode.LackAvailableUploadFile);
}
return(multipartFormDataContent);
}