如何在Dropdownlist上进行验证 [英] how to give validation on Dropdownlist

问题描述

当我从第一个下拉列表中选择值后，我有6个下拉列表具有相同的值，之后我从dropdownlist2中选择相同的值，以便时间应该给出错误它已经选择了请选择其他选项（其动态下拉列表不是静态的）

I have 6 dropdownlist with same value when i select value from first dropdownlist after that i select same value from dropdownlist2 so that time should be give an error Its already selected please select other option(Its Dynamic Dropdown not static)

推荐答案

使用 CompareValidator [ ^ ]：

Use a CompareValidator[^]:

<asp:CompareValidator runat="server"
    ControlToValidate="SecondDropDownList"
    ControlToCompare="FirstDropDownList"
    Operator="NotEqual"
    Display="Dynamic"
    Text="That value has already been selected - please chose another."
/>

对于六个列表，您需要总共15个验证器以确保没有两个列表相同的值：

• 比较清单2到清单1;
• 比较清单3到清单1;
• 比较清单3到清单2;
• 比较清单4到清单1;
• 比较清单4到清单2;
• 比较清单4到清单3;
• 比较列表5到列表1;
• 比较列表5到列表2;
• 比较列表5到列表3;
• 比较列表5到列表4 ;
• 将列表6与列表1进行比较;
• 将列表6与列表2进行比较;
• 将列表6与列表3进行比较;
• 比较清单6到清单4;
• 比较清单6到清单5;


For six lists, you'll need a total of 15 validators to ensure that no two lists have the same value:


• Compare list 2 to list 1;
• Compare list 3 to list 1;
• Compare list 3 to list 2;
• Compare list 4 to list 1;
• Compare list 4 to list 2;
• Compare list 4 to list 3;
• Compare list 5 to list 1;
• Compare list 5 to list 2;
• Compare list 5 to list 3;
• Compare list 5 to list 4;
• Compare list 6 to list 1;
• Compare list 6 to list 2;
• Compare list 6 to list 3;
• Compare list 6 to list 4;
• Compare list 6 to list 5;




- 你可以拿临时列表中的所有下拉列表。

- 对于所有下拉列表的selectedIndexChanged事件，您可以调用某个方法，该方法将使用临时列表ID检查/比较其他下拉列表中的值。



希望这会给出一些基本的想法...

- You may take all dropdown's ids in temp list.
- and for all dropdown's selectedIndexChanged event, you can call some method, which will check/ compare values from other dropdowns using temp list ids.

hope this would give some basic idea...




使用此方法

========= ================



Use This method
=========================


using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;

public partial class Default6 : System.Web.UI.Page
{
    SqlConnection con = new SqlConnection("Data Source=TMINDZ-18\\SQLEXPRESS;Initial Catalog=adharcard;Persist Security Info=True;User ID=sa;Password=sql");

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            fill_drop1();
            fill_drop2();
            fill_drop3();
        }
    }
    private void fill_drop1()
    {
        SqlCommand cmd = new SqlCommand("select id,username from login",con);
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataSet ds = new DataSet();
        da.Fill(ds);
        DropDownList1.DataSource = ds;
        DropDownList1.DataTextField = "username";
        DropDownList1.DataValueField = "id";
        DropDownList1.DataBind();
   }
    private void fill_drop2()
    {
        SqlCommand cmd = new SqlCommand("select id,username from login", con);
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataSet ds = new DataSet();
        da.Fill(ds);
        DropDownList2.DataSource = ds;
        DropDownList2.DataTextField = "username";
        DropDownList2.DataValueField = "id";
        DropDownList2.DataBind();
    }
    private void fill_drop3()
    {
        SqlCommand cmd = new SqlCommand("select id,username from login", con);
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataSet ds = new DataSet();
        da.Fill(ds);
        DropDownList3.DataSource = ds;
        DropDownList3.DataTextField = "username";
        DropDownList3.DataValueField = "id";
        DropDownList3.DataBind();
    }
    
}



尝试这种方法....任何疑问告诉我......


Try This Method....any doubt Tell me...

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