C# 如何从数据库选项卡'；这是一排吗？

我使用实体框架连接到数据库并从表中检索一些信息。我需要在下拉列表中显示此信息。我需要将每个列表项的值设置为数据库中设置的Id

public void EducationDropDownListViewer()
{
    EducationDropdown.Items.Add(new ListItem { Text = "--select--", Value = "0" });
    List<Education> educations = ModelLists.GetEducationList();
    for (int i = 0; i < educations.Count; i++)
    {
        ListItem educationListItem = new ListItem();
        Education education = educations[i];
        educationListItem.Text = education.EducationName;
        educationListItem.Value = education.Id.ToString(CultureInfo.InvariantCulture);
        EducationDropdown.Items.Add(educationListItem);
    }
}

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SelectedIndex

属性返回整个下拉列表中当前选择项的累进索引。
您正在查找返回

SelectedItem的
值的
SelectedValue
属性

protected void EducationDropdown_SelectedIndexChanged(object sender, EventArgs e)
{
    // If you accept also the item at index zero (the prompt to select) then change
    // the test below to >=
    if(EducationDropDown.SelectedIndex > 0)
        ViewState["educationid"] = Convert.ToInt32(EducationDropdown.SelectedValue);
}

protected void EducationDropdown_SelectedIndexChanged(object sender, EventArgs e)
{
    // If you accept also the item at index zero (the prompt to select) then change
    // the test below to >=
    if(EducationDropDown.SelectedIndex > 0)
        ViewState["educationid"] = Convert.ToInt32(EducationDropdown.SelectedValue);
}