Asp.net dropdownlist: no refreshing!

Last Update:2018-12-04 Source: Internet

Author: User

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<Title> webform2 </title>

<Script language = 'javascript '>
Function load (){
VaR drp2 = Document. getelementbyid ("dropdownlist2 ");
Drp2.innertext = "";
For (VAR I = 0; I <= drp2.options. Length-1; I ++ ){
Drp2.remove (I );
}
VaR drp3 = Document. getelementbyid ("dropdownlist3 ");
For (VAR I = 0; I <= drp3.options. Length-1; I ++ ){
Drp3.remove (I );
}
VaR XMLHTTP = new activexobject ("msxml2.xmlhttp ");
VaR odoc = new activexobject ("msxml2.domdocument ");
VaR state = Document. getelementbyid ("dropdownlist1"). value;
XMLHTTP. Open ("Post", "webform1.aspx? Id = "+ state, false );
XMLHTTP. Send ("");
VaR res = odoc. loadxml (XMLHTTP. responsetext );
VaR naitems = odoc. selectnodes ("// market/table/maname ");
VaR iditems = odoc. selectnodes ("// market/table/maid ");
VaR item;
VaR ID;
For (item = naitems. nextnode (), id = iditems. nextnode (); item & ID; item = naitems. nextnode (), id = iditems. nextnode ()){
VaR nastr = item. nodetypedvalue;
VaR idstr = ID. nodetypedvalue;
VaR newoption = Document. createelement ("option ");
Newoption. Text = nastr;
Newoption. value = idstr;

Drp2.options. Add (newoption );
}
Load2 ();

}
Function load2 (){
VaR drp2 = Document. getelementbyid ("dropdownlist3 ");
Drp2.innertext = "";
For (VAR I = 0; I <= drp2.options. Length-1; I ++ ){
Drp2.remove (I );
}
VaR XMLHTTP = new activexobject ("msxml2.xmlhttp ");
VaR odoc = new activexobject ("msxml2.domdocument ");
VaR state = Document. getelementbyid ("dropdownlist2"). value;
XMLHTTP. Open ("Post", "webform3.aspx? Id = "+ state, false );
XMLHTTP. Send ("");
VaR res = odoc. loadxml (XMLHTTP. responsetext );
VaR naitems = odoc. selectnodes ("// market/table/maname ");
VaR iditems = odoc. selectnodes ("// market/table/maid ");
VaR item;
VaR ID;
For (item = naitems. nextnode (), id = iditems. nextnode (); item & ID; item = naitems. nextnode (), id = iditems. nextnode ()){
VaR nastr = item. nodetypedvalue;
VaR idstr = ID. nodetypedvalue;
VaR newoption = Document. createelement ("option ");
Newoption. Text = nastr;
Newoption. value = idstr;

Drp2.options. Add (newoption );
}

}
</SCRIPT>
</Head>
<Body ms_positioning = "gridlayout" onLoad = "load ()">
<Form ID = "form1" method = "Post" runat = "server">
<Asp: dropdownlist id = "dropdownlist1" runat = "server"> </ASP: dropdownlist>
<Asp: dropdownlist id = "dropdownlist2" runat = "server"> </ASP: dropdownlist>
<Asp: dropdownlist id = "dropdownlist3" runat = "server"> </ASP: dropdownlist>
</Form>
</Body>
</Html>
-----------------------
Namespace dropdown
{
/// <Summary>
/// Summary of webform2.
/// </Summary>
Public class webform2: system. Web. UI. Page
{
Protected system. Web. UI. webcontrols. dropdownlist dropdownlist1;
Protected system. Web. UI. webcontrols. dropdownlist dropdownlist3;
Protected system. Web. UI. webcontrols. dropdownlist dropdownlist2;

Private void page_load (Object sender, system. eventargs E)
{
// Place user code here to initialize the page
If (! This. ispostback)
{
Sqlconnection con = new sqlconnection ("Server = localhost; database = star; uid = sa; Pwd = ");
Sqldataadapter da = new sqldataadapter ("select maid, maname from tabmarket where macls = 0", con );
Dataset DS = new dataset ();
Da. Fill (DS, "op ");
This. dropdownlist1.datasource = Ds. Tables [0];
This. dropdownlist1.datatextfield = "maname ";
This. dropdownlist1.datavaluefield = "maid ";
This. dropdownlist1.databind ();
This. dropdownlist1.attributes. Add ("onchange", "load ()");
This. dropdownlist2.attributes. Add ("onchange", "load2 ()");
}

}

}
}
-----------------------
Public class webform1: system. Web. UI. Page
{

Private void page_load (Object sender, system. eventargs E)
{
// Place user code here to initialize the page
// Put user code to initialize the page here
// If (this. request ["state"]! = NULL)
//{
String id = This. request ["ID"];
Sqlconnection con = new sqlconnection ("Server = localhost; database = star; uid = sa; Pwd = ;");
Sqldataadapter da = new sqldataadapter ("select maname, maid from tabmarket where maparent = @ ID and mast = 1", con );
Da. selectcommand. Parameters. Add ("@ ID", ID );
Dataset DS = new dataset ("market ");
Da. Fill (DS );

DS. writexml (response. outputstream );
Response. Flush ();
Response. End ();

//}
}
}
-----------------------------
Public class webform3: system. Web. UI. Page
{
Private void page_load (Object sender, system. eventargs E)
{
// Place user code here to initialize the page
String id = request ["ID"];
Sqlconnection con = new sqlconnection ("Server = localhost; database = star; uid = sa; Pwd = ;");
Sqldataadapter da = new sqldataadapter ("select maname, maid from tabmarket where maparent = @ ID and mast = 1", con );
Da. selectcommand. Parameters. Add ("@ ID", ID );
Dataset DS = new dataset ("market ");
Da. Fill (DS );

DS. writexml (response. outputstream );
Response. Flush ();
Response. End ();
}
}
------------------

This article is an English version of an article which is originally in the Chinese language on aliyun.com and is provided for information purposes only. This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed description of the concern or complaint, to info-contact@alibabacloud.com. A staff member will contact you within 5 working days. Once verified, infringing content will be removed immediately.

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Asp.net dropdownlist: no refreshing!

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