使用 SQLDataReader 将项目从数据库添加到 ComboBox

Question

我正在尝试将项目从数据库添加到 Windows 窗体组合框，以下代码对我有用。代码中引用的表 Course 有 2 列，CourseId 和 CourseName，我想将显示成员设置为 CourseName，将值成员设置为 CourseId。

请告诉我，我需要在以下代码中进行哪些额外更改才能实现这一点？

private void LoadCourse()
{
        SqlConnection conn = new SqlConnection(sasdbConnectionString);
        SqlCommand cmd = new SqlCommand("SELECT CourseId FROM Courses", conn);

        cmd.CommandType = CommandType.Text;

        conn.Open();

        SqlDataReader dr = cmd.ExecuteReader();

        while (dr.Read())
        {
            this.courseComboBox.Items.Add(dr.GetInt32(0));
        }

        dr.Close();

        conn.Close();
}

Answer 1

用 sql 适配器试试这个

private void LoadCourse()
 {
    SqlConnection conn = new SqlConnection(sasdbConnectionString);
    string query = "SELECT CourseId,CourseName FROM Courses";
    SqlDataAdapter da = new SqlDataAdapter(query, conn);
    conn.Open();
    DataSet ds = new DataSet();
    da.Fill(ds, "Course");
    courseComboBox.DisplayMember =  "CourseName";
    courseComboBox.ValueMember = "CourseId";
    courseComboBox.DataSource = ds.Tables["Course"];
 }

Answer 2

试试这个..！

private void LoadCourse()
{
    SqlConnection conn = new SqlConnection(sasdbConnectionString);
    SqlCommand cmd = new SqlCommand("SELECT CourseId,CourseName FROM Courses", conn);

    cmd.CommandType = CommandType.Text;

    conn.Open();

    SqlDataReader dr = cmd.ExecuteReader();

    while (dr.Read())
    {
        this.courseComboBox.DisplayMember =dr[0];
        this.courseComboBox.ValueMember = dr[1];
        this.courseComboBox.DataSource = dr;

    dr.Close();

    conn.Close();
}