用OpenXml在文档的尾部添加一个Rich Text Content Control/Plain(3)

                        Paragraph objParagraph_2 = new Paragraph(); 
                        Run objRun = new Run(); 
                        Text objText = new Text(); 
                        if (strInsertText.Length > 0) 
                            objText.Text = strInsertText; 
                        else 
                            objText.Text = "<Null>"; 
                        objRun.Append(objText); 
                        objParagraph_2.Append(objRun); 
                        objSdtContentBlock.Append(objParagraph_2); 
                        objSdtBlock.Append(objSdtContentBlock); 
                        objParagraph_1.Append(objSdtBlock); 
                        objBody.Append(objParagraph_1); 
                        objDocument.Save(); 
                    } 
                } 
                catch (Exception ex) 
                { 
                    MessageBox.Show(string.Format