winform 中 combobox 怎么实现对listview的类别查询？？

Question

急！急急！！ 急急急！！！ 请教高手！ 在 combobox 中有A、B、 C、三种类型，我选中 A 类型之后，在listview 中把所有是 A 类型的项查询出来？？？？

Answer 1

在 combobox 的 SelectedIndexChanged 事件中写查询方法，查询条件为combobox选择的值

Answer 2

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;namespace combobox与TEXT关联
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        public class hc
        {
            public DataTable mm(string sql)
            {
                DataTable dt = new DataTable();
                string sqlconn = "data source=.;database=emgn_byang_sale;uid=sa;pwd=;";
                SqlConnection ss = new SqlConnection(sqlconn);
                ss.Open();
                SqlDataAdapter sd = new SqlDataAdapter(sql, ss);
                sd.Fill(dt);
                ss.Close();
                return dt;
            }
        }        private void Form1_Load(object sender, EventArgs e)
        {
            comboBox1.Items.Add("A");
            comboBox1.Items.Add("B");
            comboBox1.Items.Add("c");
           
        }        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            hc da = new hc();
            string sql = "select namec from t_sal_client where cst_originid='" + this.comboBox1.SelectedValue.ToString() + "'";
            DataTable dt = da.mm(sql);
            
            if (dt.Rows.Count == 0)
            {
                this.comboBox2.Text = "无";
            }
            else
            {
                foreach (DataRow dr in dt.Rows)
                
               this.comboBox2.Items.Add(dr.ItemArray[0].ToString());
            }
        }    }
}

Answer 3

  private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            
            //根据comboBox1.SelectedValue的值在数据库中查询啊，把查询结果绑定到listview
        }