在组合框中添加项目

Question

我想向 combobox 添加一个项目，该项目已经与一些数据绑定。

代码：

Public Sub showSection()
        sb = New StringBuilder()
        sb.Remove(0, sb.Length)
        sb.Append("SELECT DISTINCT Section ")
        sb.Append(" FROM Employee ")
        sb.Append(" ORDER BY Section")
        Dim sqlSection As String = sb.ToString()

        da = New SqlDataAdapter(sqlSection, Conn)
        da.Fill(ds, "Section")

        dt = ds.Tables("Section")
        bs.DataSource = dt

        With cbSection
            .DisplayMember = "Section"
            .ValueMember = "Section"
            .DataSource = ds.Tables("Section")
            .DataBindings.Add("SelectedValue", bs, "Section")
        End With
End Sub

但我想添加项目，比如"---All---"，所以这应该是输出。

---All---
HR
Store
Packing
Training
Qc
Qa
Stock

Answer 1

这是一个简单的解决方案

Dim dr As DataRow = dt.NewRow()
dr("Section") = "---All---"
dr("SectionId") = 0
dt.Rows.InsertAt(dr, 0)

With cbSection
    .DisplayMember = "Section"
    .ValueMember = "SectionId"
    .DataSource = ds.Tables("Section")
    .DataBindings.Add("SelectedValue", bs, "Section")
End With

cbSection.SelectedIndex = 0