Error when uploading file using Microsoft Graph API - api

Question

I am trying to upload a large file to One Drive using Microsoft Graph API.
Uploading to One Drive works normally, but the file is damaged.
Please help me to solve the problem.
public ActionResult UploadLargeFiles(string id, [FromForm]IFormFile files)
{
string fileName = files.FileName;
int fileSize = Convert.ToInt32(files.Length);
var uploadProvider = new JObject();
var res = new JArray();
var isExistence = _mailService.GetUploadFolder(id);
if (isExistence != HttpStatusCode.OK)
{
var createFolder = _mailService.CreateUploadFolder(id);
if (createFolder != HttpStatusCode.Created)
{
return BadRequest(ModelState);
}
}
if (files.Length > 0)
{
var uploadSessionUrl = _mailService.CreateUploadSession(id, fileName);
if (uploadSessionUrl != null)
{
if (fileSize < 4194304)
{
uploadProvider = _mailService.UploadByteFile(id, uploadSessionUrl, files);
res.Add(uploadProvider);
}
}
else
{
return BadRequest(ModelState);
}
}
return Ok();
}
createUploadSession
public string CreateUploadSession(string upn, string fileName)
{
var uploadSession = _mailGraphService.CreateUploadSession(upn, fileName).Result;
var sessionResult = new UploadSessionDTO(uploadSession);
return sessionResult.uploadUrl;
}
public async Task<UploadSessionDTO> CreateUploadSession(string upn, string fileName)
{
this.InitHttpClient();
var jObject = JObject.FromObject(new { item = new Dictionary<string, object> { { "#microsoft.graph.conflictBehavior", "rename" } }, fileSystemInfo = new Dictionary<string, object> { { "#odata.type", "microsoft.graph.fileSystemInfo" } }, name = fileName });
var toJson = JsonConvert.SerializeObject(jObject);
var content = new StringContent(toJson, Encoding.UTF8, "application/json");
var response = await _client.PostAsync("users/"+ upn + "/drive/root:/MailFiles/" + fileName +":/createUploadSession", content);
if (!response.IsSuccessStatusCode)
return null;
var strData = await response.Content.ReadAsStringAsync();
dynamic uploadSession = JsonConvert.DeserializeObject<UploadSessionDTO>(strData);
return uploadSession;
}
public JObject LargeFileUpload(string upn, string url, IFormFile files)
{
var responseCode = HttpStatusCode.OK;
var jObject = new JObject();
int idx = 0;
int fileSize = Convert.ToInt32(files.Length);
int fragSize = 4 * 1024 * 1024; //4MB => 4 * 1024 * 1024;
var byteRemaining = fileSize;
var numFragments = (byteRemaining / fragSize) + 1;
while (idx < numFragments)
{
var chunkSize = fragSize;
var start = idx * fragSize;
var end = idx * fragSize + chunkSize - 1;
var offset = idx * fragSize;
if (byteRemaining < chunkSize)
{
chunkSize = byteRemaining;
end = fileSize - 1;
}
var contentRange = " bytes " + start + "-" + end + "/" + fileSize;
byte[] file = new byte[chunkSize];
using (var client = new HttpClient())
{
var content = new ByteArrayContent(file);
content.Headers.Add("Content-Length", chunkSize.ToString());
content.Headers.Add("Content-Range", contentRange);
var response = client.PutAsync(url, content);
var strData = response.Result.Content.ReadAsStringAsync().Result;
responseCode = response.Result.StatusCode;
//업로드 성공
if (responseCode == HttpStatusCode.Created)
{
JObject data = JObject.Parse(strData);
string downloadUrl = data["#content.downloadUrl"].ToString();
string itemId = data["id"].ToString();
//파일 크기 -> kb로 변환
fileSize = fileSize / 1000;
jObject = JObject.FromObject(new { name = files.Name, id = itemId, url = downloadUrl, size = (double)fileSize });
}
//업로드 충돌
else if (responseCode == HttpStatusCode.Conflict)
{
var restart = RestartByteFile(upn, url, files.Name);
responseCode = restart;
}
}
byteRemaining = byteRemaining - chunkSize;
idx++;
}
if (responseCode == HttpStatusCode.Created) { return jObject; }
else return jObject = JObject.FromObject(new { result = "실패" });
}
When I checked OneDrive, the file was uploaded normally, and when I downloaded and opened the file, it came out as a damaged file.
I wonder why the file gets corrupted when uploaded, and how to fix it.
If the problem cannot be solved, please let us know that it cannot be solved.