如何在组合框中显示与另一个组合框项目相关的项目 [英] how to show item in combobox as related to another combobox Item

问题描述

string ADDRES = Convert.ToString(comboBox1.SelectedItem);
                SqlConnection con = new SqlConnection();
                con.ConnectionString = "Data source=.;User ID=sa;Password=password;Initial Catalog=bank";
                string sql = "select NAME_PEOPLE from PEOPLE where ADDRESS='@ADDRESS' ";
                SqlCommand cmd=new SqlCommand(sql,con);
                cmd.Parameters.AddWithValue("@ADDRESS", ADDRES);
                 con.Open();
                 SqlDataAdapter ada = new SqlDataAdapter(cmd);
                     
                 DataTable dt = new DataTable();
                    ada.Fill(dt);
                if(comboBox1.SelectedIndex==1)
                {
                        
                     string w=dt.Rows[dt.Rows.Count-1]["NAME_PEOPLE"].ToString();
                            comboBox2.DataSource = dt;
                            comboBox2.DisplayMember = "NAME_PEOPLE";
                }

推荐答案

您好



这里我添加了解决方案请检查

Hi

Here i added solution please check that

private void Form2_Load(object sender, EventArgs e)
        {
            comboBox1.Items.Add("a");
            comboBox1.Items.Add("b");
            comboBox1.Items.Add("c");
            comboBox1.Items.Add("d");
            comboBox1.SelectedIndex = -1;
        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            var selectedItem = Convert.ToString(comboBox1.SelectedItem);

            //Instead of this code you can read data from database
            DataTable dt = new DataTable();
            dt.Columns.Add("Name", typeof(string));
            for(int i=0;i<3;i++)
            {
                dt.Rows.Add(selectedItem + i);
            }


            comboBox2.DataSource = null;
            comboBox2.DataSource = dt;
            comboBox2.DisplayMember = "Name";
        }

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