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);

	SignatureSettings signatureSettings = new SignatureSettings()
	{
		OwnerName = "John Doe",
		RedirectUrlAfterSignature = this.BasePath + "Signature/SignDocument",
		UniqueId = Guid.NewGuid().ToString(),
		SignerName = "Jane Doe",
		SignatureBoxes = new SignatureBox[]
		{
			new SignatureBox("txsign")
			{
				Style = SignatureBox.SignatureBoxStyle.Signature
			}
		},
		ShowSignatureBar = true		
	};

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