File uploads

The MultipartFormDataPostNetworkRequest handles file uploads using multipart/form-data encoding. It provides a fluent API for building the request content, supporting multiple files and form fields in a single request.

Uploading a file

var request = requestFactory.PostMultipart("https://api.example.com/upload")
    .AddStreamContent("file", fileStream, "photo.png", "image/png")
    .AddStringContent("description", "Profile photo");

var result = await request.ExecuteAsync<UploadResult>();

Content types

You can add three types of content to a multipart request:

AddStreamContent

Adds a file from a Stream with a file name and content type:

request.AddStreamContent("file", fileStream, "document.pdf", "application/pdf");

AddByteArrayContent

Adds a file from a byte array:

byte[] imageBytes = await File.ReadAllBytesAsync("photo.jpg");
request.AddByteArrayContent("file", imageBytes, "photo.jpg", "image/jpeg");

AddStringContent

Adds a text form field:

request.AddStringContent("title", "My Document");
request.AddStringContent("category", "reports");

Uploading multiple files

Chain multiple AddStreamContent or AddByteArrayContent calls:

var request = requestFactory.PostMultipart("https://api.example.com/upload")
    .AddStreamContent("files", stream1, "photo1.png", "image/png")
    .AddStreamContent("files", stream2, "photo2.png", "image/png")
    .AddStringContent("album", "Vacation");

var result = await request.ExecuteAsync<UploadResult>();

Best practices

• Dispose streams after the request completes. The request reads the stream during execution but doesn't take ownership of it.
• Set the correct content type for each file. Some APIs validate the content type and will reject uploads with incorrect MIME types.
• Consider file size limits. Large file uploads may need increased timeout settings on your HttpClient configuration.