我在 Excel 中有两列，但我想将某些部分导入 C# 程序

Question

我的 Excel 是：

region            city
iç anadolu        ankara
iç anadolu        ankara
iç anadolu        ankara
iç anadolu        ankara
iç anadolu        kayseri
marmara           istanbul
marmara           istanbul
marmara           istanbul
marmara           bursa
marmara           bursa

我想当在combobox1中选择iç anadolu时，只有ankara和kayseri出现在combobox2中，当在combobox1中选择marmara时，只有ankara和kayseri出现istanbul 和 bursa 出现在 combobox2 中。

我该怎么做？

这是我的代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.OleDb;
namespace trfd
{
public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
 }
   OleDbConnection baglan = new OleDbConnection(@"Provider =Microsoft.ACE.OLEDB.12.0;Data Source=C:\users\toshiba\desktop\proje_ofy\proje-1; Extended Properties='Excel 12.0 xml;HDR=YES;'");    
    private void Form1_Load(object sender, EventArgs e)
    {
        baglan.Open();
        string sql = "SELECT  * FROM [Sheet1$A1:A100]";
        OleDbCommand komut = new OleDbCommand(sql, baglan);
        OleDbDataReader dr = null;
        dr = komut.ExecuteReader();                   
        while (dr.Read()) {
            if (!comboBox1.Items.Contains(dr[0].ToString()))
                { 
        comboBox1.Items.Add(dr[0].ToString());                 
           }

}

    }
    private void button1_Click(object sender, EventArgs e)
    {        
    }
    private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
    {          
    }
    private void comboBox2_SelectedIndexChanged(object sender, EventArgs e)
    {            
    }

} }

Answer 1

按照下面的代码

public Form1()
{
    InitializeComponent();

    OleDbConnection baglan = new OleDbConnection(@"Provider =Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\d.faldu\Desktop\WindowsFormsApplication1\WindowsFormsApplication1\bin\Debug\tempExcel; Extended Properties='Excel 12.0 xml;HDR=YES;'");

    baglan.Open();
    string sql = "SELECT * FROM [Sheet1$A1:A100]";
    OleDbCommand komut = new OleDbCommand(sql, baglan);
    OleDbDataReader dr = null;
    dr = komut.ExecuteReader();
    while (dr.Read())
    {
        if (!comboBox1.Items.Contains(dr[0].ToString()))
        {
            comboBox1.Items.Add(dr[0].ToString());
        }
    }
    baglan.Close();   
}

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
    comboBox2.Items.Clear();

    OleDbConnection baglan = new OleDbConnection(@"Provider =Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\d.faldu\Desktop\WindowsFormsApplication1\WindowsFormsApplication1\bin\Debug\tempExcel; Extended Properties='Excel 12.0 xml;HDR=YES;'");
    baglan.Open();
    string sql = "SELECT * FROM [Sheet1$B1:B100]";
    OleDbCommand komut = new OleDbCommand(sql, baglan);
    OleDbDataReader dr = null;
    dr = komut.ExecuteReader();

    string sql_2 = "SELECT * FROM [Sheet1$A1:A100]";
    OleDbCommand komut_2 = new OleDbCommand(sql_2, baglan);
    OleDbDataReader dr_2 = null;
    dr_2 = komut_2.ExecuteReader();
    while (dr_2.Read() && dr.Read())
    {
        if (dr_2[0].ToString() == comboBox1.SelectedItem.ToString())
        {
            if (!comboBox2.Items.Contains(dr[0].ToString()))
            {
                comboBox2.Items.Add(dr[0].ToString());
            }
        }
    }
    baglan.Close();
}

我在 Excel 中有两列，但我想将某些部分导入 C# 程序

I have two colums in Excel but I want to import certain sections to C# program

c#

oledb

excel

combobox