Stream to Base64String - Out of memory exception

Question

Stream to Base64String - Out of memory exception

Nirenjana Raghupathy 26

Hi,

We are trying to read a file from Sharepoint document library and convert it to Base64 string using the below code:
var spFile = ctx.Web.GetFileByServerRelativeUrl(fileUrlPath);
var spFileContent = spFile.OpenBinaryStream();
ctx.Load(spFile);
ctx.ExecuteQuery();
MemoryStream stream = new MemoryStream();
if (spFileContent != null && spFileContent.Value != null)
{
spFileContent.Value.CopyTo(stream);
}
return Convert.ToBase64String(stream.ToArray());

We are getting a "System.OutOfMemory exception" while converting the stream array to Base64 string.
Does anyone know a solution for this?

2 answers

Your answer

Answer 1

satya karki 996 MVP

Hi,

try this way

var file = clientContext.Web.GetFileByServerRelativeUrl(oAttachment.ServerRelativeUrl);    
            clientContext.Load(file);    
            clientContext.ExecuteQuery();    
            ClientResult<System.IO.Stream> data = file.OpenBinaryStream();    
            clientContext.Load(file);    
            clientContext.ExecuteQuery();    
            using (System.IO.MemoryStream mStream = new System.IO.MemoryStream())    
            {    
               if (data != null)    
               {    
                  data.Value.CopyTo(mStream);    
                  byte[] imageArray = mStream.ToArray();    
                  imgBase64Str = Convert.ToBase64String(imageArray);    
               }    
            }

https://www.c-sharpcorner.com/article/read-list-item-attachmentimage-and-convert-into-base64-string-csom-using-app-o/

Nirenjana Raghupathy 26 Reputation points

2022-08-11T09:05:43.723+00:00

Hi Satyakarki,

Thank you for your quick response. We tried this way as well.
But unfortunately, this is also throwing the same exception.
This is occurring if the file size is over 100 MB

Thanks,
Nirenjana
Naveenkumar C 6 Reputation points

2022-08-11T09:10:14.617+00:00

I tried the same code, but the file Size which I am reading from document library is around 240MB.
I was able to read entire file content into byte array byte[270379968] .
I am getting exception in converting the same to base64string which is required to pass as parameter to encodian API.

imgBase64Str = Convert.ToBase64String(imageArray); // Here facing issue

Please suggest.

satya karki 996 MVP

Hi,

Here is an example for buffer large file.

private void ConvertLargeFile()  
{  
    using (var inputStream  = new FileStream("C:\\Users\\test\\Desktop\\my.zip", FileMode.Open, FileAccess.Read))   
    {  
        byte[] buffer = new byte[MultipleOfThree];  
        int bytesRead = inputStream.Read(buffer, 0, buffer.Length);  
        while(bytesRead > 0)  
        {  
            String base64String = Convert.ToBase64String(buffer, 0, bytesRead);  
            File.AppendAllText("C:\\Users\\test\\Desktop\\Base64Zip", base64String);   
            bytesRead = inputStream.Read(buffer, 0, buffer.Length);             
        }  
    }  
}

https://stackoverflow.com/questions/32702965/convert-a-very-large-binary-file-into-a-base64string-incrementally

Answer 2

Rijwan Ansari 766 MVP

Hi,

You can use below code for your case.

string imgBase64Str = "";  
var spFile = ctx.Web.GetFileByServerRelativeUrl(fileUrlPath);  
var spFileContent = spFile.OpenBinaryStream();  
ctx.Load(spFile);  
ctx.ExecuteQuery();  
using (MemoryStream stream = new MemoryStream())    
     {  
	if (spFileContent != null && spFileContent.Value != null)  
         {  
		spFileContent.Value.CopyTo(stream);  
		byte[] imageArray = mStream.ToArray();  
		imgBase64Str = Convert.ToBase64String(imageArray);  
         }  
     }    
  
return imgBase64Str

Nirenjana Raghupathy 26 Reputation points

2022-08-11T09:12:05.033+00:00

Hi rijwanansari,

Thank you for your quick response. We tried this way as well.
But unfortunately, this is also throwing the same exception.
This is occurring if the file size is over 100 MB

Thanks,
Nirenjana
Rijwan Ansari 766 Reputation points MVP

2022-08-11T09:28:38.093+00:00

Hi

You can do buffer.
Example
https://manishrules.wordpress.com/2016/05/31/convert-the-large-file-to-base64-encoded-string/
Tong Zhang_MSFT 9,251 Reputation points

2022-08-23T01:46:13.163+00:00

Hi @Nirenjana Raghupathy ,

Do you have any further questions about this thread? If you have any questions or progress, you can contact me in time.
Nirenjana Raghupathy 26 Reputation points

2022-09-22T13:37:45.38+00:00

Hi @Tong Zhang_MSFT ,

Thank you for your response.
We are trying with the below code to convert a Word Document into a byte array and pass it as a parameter to Encodian API.
This code works until the file size of 170MB.
Beyond 170MB, we are unable to get the byte array. We are getting the "out of memory exception".

Can you please let us know if you were able to successfully read documents over 170 MB into byte array ?243923-bytearraycode.txt
@Naveenkumar C

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Stream to Base64String - Out of memory exception

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