protected void Button1_Click(object sender, EventArgs e) {     int a =int.Parse( DropDownList1.SelectedValue);                                //用于取得行数     int  b = int.Parse(DropDownList2.SelectedValue);                               //用于取的列数 ，int.Parse();和Convert.ToInt32作用相同，是将转换为整型。     Table1.BorderColor = System.Drawing.Color.DarkGoldenrod;                          Table1.BorderWidth = 2;                                                        //这两句用于设置表格的属性     for (int i = 0; i < a; i++)     {         TableRow w = new TableRow();                                              //实例化行对象         for (int j = 0; j < b; j++)         {             TableCell q = new TableCell();                                       //实例化单元格对象             q.BackColor = System.Drawing.Color.Blue;                             //设置单元格的背景颜色属性。             Button r = new Button();                                            //实例化按钮对象，用于向表格中添加。             if (i == 2 && j == 2)                                               //向第三行、第三列中中添加按钮             {                 q.Controls.Add(r);                                              //单元格中添加按钮，添加其他控件的方法相同             }                                                                              q.BorderWidth = 2;             w.Cells.Add(q);                                                      //将单元格添加到行中。         }         Table1.Rows.Add(w);                                                     //将行添加到表格中     } }