Jose estoy feliz ya funciona muchas gracias a ti y todas las personas que con su ayuda y consejos me dieron mucho apoyo y herramientas para aprender
te cuento que el problema era un detalle, me di cuenta viendo un articulo en el que insertan un drop dentro de un datagrid
tenia que poner la propiedad del drop1 asi: OnSelectedIndexChanged="DropDownList2_SelectedInde xChanged" y asi funciono
abajo dejo el codigo para el qeu lo necesite
Y un millon de gracias
Saludos
y la del drop2 asi :_ OnSelectedIndexChanged="DropDownList1_SelectedInde xChanged"
<%@ Page language="VB" Codebehind="WebForm1.aspx.cs" AutoEventWireup="true" Inherits="Rainbow.DesktopModules.Agencia.WebForm1" debug=true%>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<HTML>
<script language="VB" id="Script1" runat="server">
Sub Page_Load(Sender As Object, E As EventArgs)
If Not IsPostBack
Dim ds As DataSet
Dim MyConnection As SqlConnection
Dim MyCommand As SqlDataAdapter
ds = New DataSet ()
MyConnection = New SqlConnection("SERVER=MDS01; DATABASE=be; INTEGRATED SECURITY=false;PASSWORD=sa;USER=sa")
MyCommand = New SqlDataAdapter ("select EstadoID, Nombre_Estado from Estado" , MyConnection)
MyCommand.Fill(ds,"Estado")
DropDownList1.DataSource = ds.Tables("Estado").DefaultView
DropDownList1.DataTextField = "Nombre_Estado"
DropDownList1.DataValueField ="EstadoID"
DropDownList1.DataBind()
DropDownList1.Items.Insert(0, "Seleccione un item")
DropDownList1.SelectedIndex = 0
end if
end sub
Private Sub DropDownList1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)
Dim DS As DataSet
Dim MyConnection As SQLConnection
Dim MyCommand As SqlDataAdapter
MyConnection = New SQLConnection("SERVER=MDS01; DATABASE=be; INTEGRATED SECURITY=false;PASSWORD=sa;USER=sa")
MyCommand = New SqlDataAdapter("select CiudadID, Nombre_Ciudad from Ciudad where EstadoID=" &DropDownList1.SelectedItem.Value,MyConnection)
DS = new DataSet()
MyCommand.Fill(DS, "Ciudad")
Dropdownlist2.DataSource=ds.Tables("Ciudad").Defau ltView
Dropdownlist2.datatextfield="Nombre_Ciudad"
Dropdownlist2.datavaluefield="CiudadID"
Dropdownlist2.DataBind()
Dropdownlist2.Items.Insert(0, "Seleccione un item")
Dropdownlist2.SelectedIndex = 0
End Sub
Private Sub DropDownList2_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)
Dim ds As DataSet
Dim MyConnection As SqlConnection
Dim MyCommand As SqlDataAdapter
ds = New DataSet ()
MyConnection = New SqlConnection("SERVER=MDS01; DATABASE=be; INTEGRATED SECURITY=false;PASSWORD=sa;USER=sa")
MyCommand = New SqlDataAdapter ("select UbicacionID, Descripcion from Ubicacion WHERE CiudadID=" &Dropdownlist2.SelectedItem.Value, MyConnection)
MyCommand.Fill(ds,"Ubicacion")
DropDownList3.DataSource = ds.Tables("Ubicacion").DefaultView
DropDownList3.DataTextField = "Descripcion"
DropDownList3.DataValueField ="UbicacionID"
DropDownList3.DataBind()
DropDownList3.Items.Insert(0, "Seleccione un item")
DropDownList3.SelectedIndex = 0
End Sub
</script>
<body>
<form id="WebForm1" method="post" runat="server">
<asp:dropdownlist id="DropDownList1" runat="server" AutoPostBack="True" OnSelectedIndexChanged="DropDownList1_SelectedInde xChanged"></asp:dropdownlist>
<asp:DropDownList id="Dropdownlist2" runat="server" AutoPostBack="True" OnSelectedIndexChanged="DropDownList2_SelectedInde xChanged"></asp:DropDownList>
<asp:dropdownlist id="Dropdownlist3" runat="server" AutoPostBack="True" ></asp:dropdownlist>
</form>
</body>
</HTML>