c# - 如何获取 ComboBox 的值而不是文本

Question

我有一个组合框cmbCourses，我正在填充我的代码

var _courses = new DatabaseHandler().GetAllCourses();
            foreach (var a in _courses)
            {
                ComboBoxItem item = new ComboBoxItem();
                item.Text = a.Value;
                item.Value = a.Key;

                cmbCourses.Items.Add(a.Value);
            }

 public Dictionary<int, String> GetAllCourses()
    {
        Dictionary<int, String> courses = new Dictionary<int, String>();

        var connection = DatabaseConnector.Instance();

        if(connection.IsConnect())
        {
            connection.Connection.Open();
            string query = "SELECT * FROM courses";
            cmd = new MySqlCommand(query, connection.Connection);
            cmd.Prepare();
            var result = cmd.ExecuteReader();

            while(result.Read())
            {
                courses.Add(result.GetInt16(0), result.GetString(1));
            }
        }
        connection.Connection.Close();

        return courses;
    }

但是当我尝试获取 key 时，它显示的是值使用此代码

MessageBox.Show(cmbCourses.SelectedItem.ToString());

Answer 1

您只是将值添加到 ComboBox。将 KeyValuePair 添加到 ComboBox 并设置 DisplayMemberPath 和 SelectedValuePath 属性:

var _courses = new DatabaseHandler().GetAllCourses();
foreach (var a in _courses)
{
    cmbCourses.Items.Add(a);
}
cmbCourses.DisplayMemberPath = "Value";
cmbCourses.SelectedValuePath = "Key";

然后您可以像这样获取所选项目的 key :

var item = cmbCourses.SelectedItem as KeyValuePair<int, String>;
if (item != null)
    MessageBox.Show(item.Key);