为什么只能取15个汉字，多余了就自动去掉了啊?

Question

代码如下：我选中checkboxlist后，只能往数据库里添加15人汉字，多余了，就自动去掉了，我没有限制字数啊，这是为什么啊?
        ///获取检验医技cheboxlist的内容                
                     StringBuilder sb1 = new StringBuilder();                     for (int i = 0; i < CheckBoxList2.Items.Count; i++)                         if (CheckBoxList2.Items[i].Selected)
                         {                             sb1.Append((CheckBoxList2.Items[i]).Text);
                             sb1.Append(",");                         }
        ///获取checkboxlist3的值                     for (int i = 0; i < CheckBoxList3.Items.Count; i++)
                         if (CheckBoxList3.Items[i].Selected)
                         {                             sb1.Append((CheckBoxList3.Items[i]).Text);
                             sb1.Append(",");                         }

Answer 1

使用sqlparamter时指定了长度??????????
这个可能性比较大

Answer 2

如果数据训是Varchar（１５）那么改成Nvarchar(15）就可以了.

Answer 3

这是有关的全部代码
  protected void btn_y_Click(object sender, EventArgs e)
    {
        StringBuilder sb = new StringBuilder();        for (int i = 0; i < CheckBoxList1.Items.Count; i++)            if (CheckBoxList1.Items[i].Selected)
            {                sb.Append((CheckBoxList1.Items[i]).Text);
                sb.Append(",");
                //Session["s_aids"] = sb;
                     }
        ///获取检验医技cheboxlist的内容
                 if (DropDownList2.SelectedValue=="检验医技")
                 {
                     StringBuilder sb1 = new StringBuilder();                     for (int i = 0; i < CheckBoxList2.Items.Count; i++)                         if (CheckBoxList2.Items[i].Selected)
                         {                             sb1.Append((CheckBoxList2.Items[i]).Text);
                             sb1.Append(",");                         }
                         else
                         {                             Jscript.Alert("请输入您的值");
                         
                         }
                }
        ///获取checkboxlist3的值
                                     for (int i = 0; i< CheckBoxList3.Items.Count; i++)
                         if (CheckBoxList3.Items[i].Selected)
                         {                             sb1.Append((CheckBoxList3.Items[i]).Text);
                             sb1.Append(",");                         }                                                                         for (int i = 0; i < CheckBoxList4.Items.Count; i++)                         if (CheckBoxList4.Items[i].Selected)
                         {
                             sb1.Append((CheckBoxList4.Items[i]).Text);
                             sb1.Append(",");                         }                 
                                        for (int i = 0; i < CheckBoxList5.Items.Count; i++)
                         if (CheckBoxList5.Items[i].Selected)
                         {
                             sb1.Append((CheckBoxList5.Items[i].Text));
                             sb1.Append(",");                         }
                              
                    
                      for (int i = 0; i < CheckBoxList6.Items.Count; i++)                         if (CheckBoxList6.Items[i].Selected)
                         {
                             sb1.Append((CheckBoxList6.Items[i].Text));
                             sb1.Append(",");
                         }                      
        int s_image = 1;                             try
        {
                       //string s_qiyu = Convert.ToString(Session["s_aids"]);            bool result = (new Member_all()).Mhickey_insert(txt_name.Text.Trim(), DropDownList1.SelectedValue, sb.ToString().Trim(), DropDownList2.SelectedValue, sb1.ToString(), txt_xinghao.Text.Trim(), txt_shuliang.Text, txt_dianjia.Text, txt_changshang.Text, txt_shouming.Text.Trim(), s_image, txt_yiaoqiu.Text.Trim(), txt_zhichi.Text.Trim());
            if (result == false)
            {                Jscript.Alert("请稍后注册");            }            else            {                Jscript.AlertAndRedirect("添加成功","Mhickey_issue.aspx");
            
            }
        
        
        
        
        }
        catch(System.Data.SqlClient.SqlException ex)
        {            throw new Exception(ex.Message);
        }
    }
    /// <summary>
    ///  
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    protected void DropDownList2_SelectedIndexChanged(object sender, EventArgs e)
    {        if (DropDownList2.SelectedValue == "检验医技")
        {
           
            CheckBoxList2.Visible = true;
            Panel2.Visible = false;
            Panel3.Visible = false;
            Panel4.Visible = false;
            Panel5.Visible = false;        
         }
         if (DropDownList2.SelectedValue == "基础设备")
         {
            
             Panel2.Visible = true;
             Panel3.Visible = false;
             Panel4.Visible = false;
             Panel5.Visible = false;
                  }         if (DropDownList2.SelectedValue == "手术治疗")
         {
            
             Panel2.Visible = false;
             Panel3.Visible = true;
             Panel4.Visible = false;
             Panel5.Visible = false;
         }         if (DropDownList2.SelectedValue == "监测护理")
         {
           
             Panel2.Visible = false;
             Panel3.Visible = false;
             Panel4.Visible = true;
             Panel5.Visible = false;
         }
         if (DropDownList2.SelectedValue == "家用医疗")
         {
            
             Panel2.Visible = false;
             Panel3.Visible = false;
             Panel4.Visible = false;
             Panel5.Visible = true;
         }   }

Answer 4

Member_all.Mhickey_insert
中如果指定参数类型为ntext
 则不要同时指定其长度为16
ntext(16)存放的是指针不是数据块

Answer 5

Member_all.Mhickey_insert
中如果指定参数类型为ntext
 则不要同时指定其长度为16
ntext(16)存放的是指针不是数据块

Answer 6

其是能过blackant2(乔峰)老兄一指，小弟，已经明白几分，加分