test.razor

[JSInvokable("LoadDocumentFromFile")]
public void LoadDocumentFromFile(string filename)
{
	// check if the file exists
	if (!System.IO.File.Exists(filename))
	{
		return;
	}

	// load the file into a byte array
	byte[] bDocument = System.IO.File.ReadAllBytes(filename);

	// invoke the JS function 'loadDocument' to load back to the modified document
	_txdocumentviewer?.InvokeVoidAsync("loadDocument", new object[] { Convert.ToBase64String(bDocument), filename });
}