C#comboBox院系专业班级的联动

[qq_35059981]

院系SchoolTable 院系编号Xno 院系名称Xname
专业 MajorTable 专业编号Mno 专业名称Xname 院系编号Xno
班级ClassTable 班级名称Bno 专业编号Mno 院系编号Xno

[kingtiy]

这个是要添加SelectedIndexChanged事件 依据当前选中的项,去修改需要联动的项的当前value值应该可以了.

[user2007001]

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
using System.Windows.Forms;

namespace WindowsFormsApplication2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private static string strConn = "Data Source=127.0.0.1;Initial Catalog=TestPARTITION;Persist Security Info=True;User ID=sa;PASSWORD=密码";
       
        private void cbo院系_Enter(object sender, EventArgs e)
        {
            cbo院系.Items.Clear();
            SqlConnection conn = new SqlConnection(strConn);
            conn.Open();
            string strSQL = "SELECT SchoolTable.Xname FROM SchoolTable";
            SqlCommand cmd = new SqlCommand(strSQL, conn);
            SqlDataReader sdr = cmd.ExecuteReader();
            while (sdr.Read())
            {
                cbo院系.Items.Add(sdr[0]);
            }
            conn.Close();
        }

        private void cbo专业_Enter(object sender, EventArgs e)
        {
            cbo专业.Items.Clear();
            SqlConnection conn = new SqlConnection(strConn);
            conn.Open();
            string strSQL = "SELECT MajorTable.Xname FROM MajorTable";
            if (cbo院系.Text != "")
            {
                strSQL = "SELECT MajorTable.Xname FROM MajorTable WHERE MajorTable.Xno in (SELECT SchoolTable.Xno FROM SchoolTable WHERE SchoolTable.Xname='" + cbo院系.Text + "')";
            }
            SqlCommand cmd = new SqlCommand(strSQL, conn);
            SqlDataReader sdr = cmd.ExecuteReader();
            while (sdr.Read())
            {
                cbo专业.Items.Add(sdr[0]);
            }
            conn.Close();
        }

        private void cbo班级_Enter(object sender, EventArgs e)
        {
            cbo班级.Items.Clear();
            SqlConnection conn = new SqlConnection(strConn);
            conn.Open();
            string strSQL = "SELECT ClassTable.Bno FROM ClassTable";
            if (cbo专业.Text != "")
            {
                strSQL = "SELECT ClassTable.Bno FROM ClassTable WHERE ClassTable.Mno in (SELECT MajorTable.Mno FROM MajorTable WHERE MajorTable.Xname='" + cbo专业.Text + "')";
            }
            SqlCommand cmd = new SqlCommand(strSQL, conn);
            SqlDataReader sdr = cmd.ExecuteReader();
            while (sdr.Read())
            {
                cbo班级.Items.Add(sdr[0]);
            }
            conn.Close();
        }
    }
}

[阿拉敏敏]

不明觉厉,怎么进入sql板块了.