如何更快地加载 vb.net 组合框

Question

我是 Vb.net 的新手，我使用此代码从 Mysql 数据库加载组合框。 效果很好，但速度很慢

有没有办法在一个查询中执行所有这些并加载所有组合框或另一种更快地执行此任务的方法？

    AbrirDB()
    comandomysql.CommandText = "select distinct TblMarcas.marca from TblMarcas order by marca"
    Try
        Lector = comandomysql.ExecuteReader
        Lector.Read()
        .cbom.Properties.Items.Clear()
        If Lector.HasRows Then
            .cbom.Properties.Items.Add(Lector.Item("marca"))
            Do While Lector.Read
                .cbom.Properties.Items.Add(Lector.Item("marca"))
            Loop
        Else
        End If
    Catch ex As Exception
        DevExpress.XtraEditors.XtraMessageBox.Show(Err.Number & Err.Description)
        If conexion.State = ConnectionState.Open Then conexion.Close()
    End Try
    CerrarDb()




    'CARGO  Categorias a treelist
    AbrirDB()
    comandomysql.CommandText = "select distinct TblCategorias.categoria from TblCategorias order by categoria ASC"
    Try
        Lector = comandomysql.ExecuteReader
        Lector.Read()
        .cboc.Properties.Items.Clear()
        If Lector.HasRows Then
            .cboc.Properties.Items.Add(Lector.Item("categoria"))
            Do While Lector.Read
                .cbocategoria.Properties.Items.Add(Lector.Item("categoria"))
            Loop
        Else

        End If

    Catch ex As Exception
        DevExpress.XtraEditors.XtraMessageBox.Show(Err.Number & Err.Description)
        If conexion.State = ConnectionState.Open Then conexion.Close()
    End Try
    CerrarDb()


    'CARGO Subcategorias
    AbrirDB()
    comandomysql.CommandText = "select distinct TblSubcategorias.subcategoria from TblSubcategorias order by subcategoria ASC"
    Try
        Lector = comandomysql.ExecuteReader
        Lector.Read()
        .cbos.Properties.Items.Clear()
        If Lector.HasRows Then
            .cbos.Properties.Items.Add(Lector.Item("subcategoria"))
            Do While Lector.Read
                .cbos.Properties.Items.Add(Lector.Item("subcategoria"))
            Loop

        End If

    Catch ex As Exception
        DevExpress.XtraEditors.XtraMessageBox.Show(Err.Number & Err.Description)
        If conexion.State = ConnectionState.Open Then conexion.Close()
    End Try
    CerrarDb()

任何帮助将不胜感激。

Answer 1

尝试：
myCombo.SuspendLayout()
暗表作为新的 DataTable()
table.Load(MyDataReader)
myCombo.DataSource=表
myCombo.DisplayMember="column1"
myCombo.ResumeLayout()