使用所选项目更改组合框 c# 从数据库加载文本框

Question

当我尝试加载包含两个组合框和两个文本框的表单时出现异常我从数据库加载 Combobox 项目，我尝试从 table Bureau 加载数据并将它们填充到两个文本框中图片： [我得到的异常]

[我的表格]

public partial class Modifier : Form
{

    public DataSet ds = new DataSet();

    public DataSet ds2 = new DataSet();

    public SqlCeConnection conn = new SqlCeConnection(@"Data Source=\Program Files\projetpfe\Inventaire.sdf");

    public SqlCeDataAdapter da, da2;
    public SqlCeCommand cmd, cmd2;
    public SqlCeDataReader dr,dr2;
    public Modifier()
    {
        InitializeComponent();

        this.da = new SqlCeDataAdapter("Select Code_locale from Bureau", conn);
        this.da2 = new SqlCeDataAdapter("Select DISTINCT Adresse from Bureau ", conn); 
        this.cmd = new SqlCeCommand("Select * from Bureau where Code_locale='" + comboBox1.SelectedValue + "'", conn);

        conn.Open();

    }

    private void Modifier_Load(object sender, EventArgs e)
    {

        this.ds.Tables.Clear();
        this.da.Fill(this.ds, "Bureau");
        comboBox1.DataSource = this.ds.Tables["Bureau"];
        comboBox1.DisplayMember = "Code_locale";
        this.ds2.Tables.Clear();
        this.da2.Fill(this.ds2, "Bureau");
        comboBox2.DataSource = this.ds2.Tables["Bureau"];
        comboBox2.DisplayMember = "Adresse";
        dr = cmd.ExecuteReader();
        while (dr.Read())
        {
            textBox1.Text = dr[1].ToString();
            textBox2.Text = dr[2].ToString();
        }
    }

Answer 1

我解决了我的问题，我使用了事件组合框选择更改，我将所有代码复制到组合框选择更改事件，它解决了我的问题，当我选择一个组合框项目时，文本框显示数据阅读器

使用所选项目更改组合框 c# 从数据库加载文本框

Load Textbox from database using selected item changed combobox c#

c#

windows-ce

visual-studio