public static void Run()
{
// ExStart:ModifyFormField
// The path to the documents directory.
string dataDir = RunExamples.GetDataDir_AsposePdf_Forms();
// Open document
Document pdfDocument = new Document(dataDir + "ModifyFormField.pdf");
// Get a field
TextBoxField textBoxField = pdfDocument.Form["textbox1"] as TextBoxField;
// Modify field value
textBoxField.Value = "New Value";
textBoxField.ReadOnly = true;
dataDir = dataDir + "ModifyFormField_out.pdf";
// Save updated document
pdfDocument.Save(dataDir);
// ExEnd:ModifyFormField
Console.WriteLine("\nForm field modified successfully.\nFile saved at " + dataDir);
}
}