// The path to the documents directory.
string dataDir = RunExamples.GetDataDir_Text();

Dictionary<string, string> replacements = new Dictionary<string, string>();
replacements.Add("voice over", "voice over new text");

// Load the document into Aspose.Note.
Document oneFile = new Document(dataDir + "Aspose.one");

IList<Page> pageNodes = oneFile.GetChildNodes<Page>();


// Get all RichText nodes
IList<RichText> textNodes = pageNodes[0].GetChildNodes<RichText>();

foreach (RichText richText in textNodes)
{
    foreach (KeyValuePair<string, string> kvp in replacements)
    {
        if (richText != null && richText.Text.Contains(kvp.Key))
        {
            // Replace text of a shape
            richText.Text = richText.Text.Replace(kvp.Key, kvp.Value);
        }
    }
}
dataDir = dataDir + "ReplaceTextOnParticularPage_out.pdf";
// Save to any supported file format
oneFile.Save(dataDir, SaveFormat.Pdf);