VS2005 C# groupbox绑定3个radioButton后 不能更新我所选的某一个按钮

Question

绑定是            binding = new Binding("Text", dsMain.Tables[0], "service_request", true);
                  binding.Format += new ConvertEventHandler(binding_Format);
                  groupBox1.DataBindings.Add(binding);               void binding_Format(object sender, ConvertEventArgs e)
        {
            string val = dsMain.Tables[0].Rows[0]["service_request"].ToString();             switch (val)               {                  case  "A":                {                   e.Value = "A";                     this.radioButton1.Checked = true;                   this.radioButton2.Checked = false;                   this.radioButton3.Checked = false;                   break;                  }               case "B":                {                    e.Value = "B";                 this.radioButton1.Checked = false;                 this.radioButton2.Checked = true;                 this.radioButton3.Checked = false;                  break;                 }                case "C":                {                    e.Value = "C";                this.radioButton1.Checked = false;                this.radioButton2.Checked = false;                this.radioButton3.Checked = true;               break;                }
             }
            //throw new Exception("The method or operation is not implemented.");
        }
当我选择radioButton2为TRUE时，但是保存更新时 adapterMain.Update(dsMain); dsmain表 TABLE 就是不能把service_request字段 B保存进去 为什么  

Answer 1

更新程序 部分 /// <summary>
            /// 保存数据
            /// </summary>
        private void SaveData()
        {
   
                    dsMain.Tables[0].NewRow();
 
                    dsMain.EndInit(); 
   
            adapterMain.Update(dsMain);        }

Answer 2

dsMain.Tables[0].NewRow();
添加了一行，什么数据也没有

Answer 3

设置adapterMain 的插入，更新语句了没？