/// <summary>
/// 向指定位置添加空行
/// </summary>
/// <param name="mydoc"></param>
/// <param name="str"></param>
/// <param name="spacenum"></param>
public void AddSpaceLine(Spire.Doc.Document mydoc, string str, int spacenum)
{
var myts = mydoc.FindAllString(Regex.Replace(str, @"\r\n", ""), false, false);
for (int spaceindex = 0; spaceindex < spacenum; spaceindex++)
{
myts[myts.Length - 1].GetAsOneRange().OwnerParagraph.AppendText("\r\n");
}
}