ASP practical class library-dropdownlist

<%
'<Class>
'<Name> dropdownlist </Name>
'<Description> <! [CDATA [drop-down box; Author: Christmas pineapple package]> </description>
'<Attributes>
'<Attribute name = "ID" comment = "write only; drop-down option box ID"/>
'<Attribute name = "datatextfield" comment = "display the column number of the database field corresponding to the text, for example, {0}; default value: {0};"/>
'<Attribute name = "datavaluefield" comment = "value corresponds to the column number of the database field; default value: {1};"/>
'<Attribute name = "selectedindex" comment = "Default Option Index"/>
'<Attribute name = "selectedvalue" comment = "default option value"/>
'<Attribute name = "style" comment = "drop-down option box style"/>
'<Attribute name = "islist" comment = "list display"/>
'<Attribute name = "multiple" comment = "whether multiple options are allowed; valid only when islist = true;"/>
'<Attribute name = "datasource" comment = "Data Source (disconnected record set)"/>
'</Attributes>
'<Methods>
'<Method name = "addheader (byval strtext, byval strvalue)" comment = "add option Header"/>
'<Method name = "databind ()" comment = "data binding. The drop-down box is displayed."/>
'</Methods>
'</Class>

Class dropdownlist

Private ID _ 'drop-down box ID
Private datatextfield _ 'displays the column number of the database field corresponding to the text, for example, {0}; default value: {0 };
The private datavaluefield _ 'value corresponds to the column number of the database field. The default value is {1 };
Private selectedindex _ 'default option Index
Private selectedvalue _ 'Default Value
Private style _ 'style
Private header _ 'option header information
Whether Private islist _ 'is displayed as a list
Private multiple _ 'can be selected multiple times?
Private datasource _ 'Data Source
Private recordcount _ 'number of records
 
'Return the drop-down box ID
Public property get ID ()
Id = ID _
End Property
 
'Set the drop-down option box ID
Public property let ID (byval Strid)
ID _ = Strid
End Property
 
'Set the column number of the database field corresponding to the displayed text
Public property let datatextfield (byval strfieldnumber)
Datatextfield _ = strfieldnumber
End Property
 
'Set the column number corresponding to the database Field
Public property let datavaluefield (byval strfieldnumber)
Datavaluefield _ = strfieldnumber
End Property
 
'Set the index of the default option
Public property let selectedindex (byval intindex)
If intindex = "" or not isnumeric (intindex) or intindex <0 then
Intindex =-1
End if
Selectedindex _ = intindex
End Property
 
'Set the default option value
Public property let selectedvalue (byval value)
Selectedvalue _ = Value
End Property
 
'Set the style
Public property let style (byval strstyle)
Style _ = strstyle
End Property
 
'Set whether to display the list
Public property let islist (byval boolvalue)
If boolvalue = true then
Islist _ = true
Else
Islist _ = false
End if
End Property
 
'Set whether to select multiple
Public property let multiple (byval boolvalue)
If boolvalue = true then
Multiple _ = true
Else
Multiple _ = false
End if
End Property
 
'Set the data source
Public property let datasource (byref objrs)
Set datasource _ = objrs
Recordcount _ = datasource _. recordcount
End Property
 
'Add option Headers
Public Function addheader (byval strtext, byval strvalue)
Header _ = "<option value =" & strvalue & ""> "& strtext &" </option> "& vbcrlf
End Function
 
'Bind
Public Function databind ()
Response. Write ("<! -- Drop-down option box "& ID _ &" start --> "& vbcrlf)
'Determine whether the list is displayed
If islist _ = true then
If multiple _ = true then
Response. write ("<select name =" & ID _ & "id =" & ID _ & "class =" & Style _&"" "size =" & recordcount _ & "" multiple = "" multiple ""> "& vbcrlf)
Else
Response. write ("<select name =" & ID _ & "id =" & ID _ & "class =" & Style _&"" "size =" & recordcount _ & ""> "& vbcrlf)
End if
Else
Response. write ("<select name =" & ID _ & "id =" & ID _ & "class =" & Style _&"" ">" & vbcrlf)
End if
'Output option Headers
Response. Write (header _)
'Output data
Datasource _. movefirst ()
Dim introw
For introw = 0 to recordcount _-1
If (selectedindex _ <>-1 and selectedindex _ = introw) or (selectedvalue _ <> "" And strcomp (selectedvalue _, parsevaluetemplate (datavaluefield _), 0) = 0) then
Response. write ("<option value =" & parsevaluetemplate (datavaluefield _) & "" selected = "" selected ">" & parsetexttemplate (datatextfield _) & "</option>" & vbcrlf)
Else
Response. Write ("<option value =" & parsevaluetemplate (datavaluefield _) & ""> "& parsetexttemplate (datatextfield _) &" </option> "& vbcrlf)
End if
Datasource _. movenext ()
Next
Response. Write ("</SELECT>" & vbcrlf)
Response. Write ("<! -- Drop-down option box "& ID _ &" end --> "& vbcrlf)
Datasource _. Close ()
Set datasource _ = nothing
End Function
 
'Parsing Template
Private function parsetemplate (byval stritemtemplate, byref arrtemplate, byref arrindex)
If isarray (arrtemplate) then
For I = 0 to ubound (arrtemplate)
If I <ubound (arrtemplate) then
Parsetemplate = parsetemplate & arrtemplate (I) & eval (arrindex (I ))
Else
Parsetemplate = parsetemplate & arrtemplate (I)
End if
Next
Exit Function
End if
Dim objregexp, objmatches, strtemp, arrtemp, I, arrtemplen
Set objregexp = new Regexp
Objregexp. pattern = "({) (\ D + )(})"
Objregexp. ignorecase = true
Objregexp. Global = true
Strtemp = objregexp. Replace (stritemtemplate, "{chcw_separator }")
Arrtemp = Split (strtemp, "{chcw_separator }")
Set objmatches = objregexp. Execute (stritemtemplate)
Arrtemplen = ubound (arrtemp)
Redim arrtemplate (arrtemplen)
Redim arrindex (arrTempLen-1)
For I = 0 to arrtemplen
If I <arrtemplen then
Parsetemplate = parsetemplate & arrtemp (I) & datasource _ (CINT (objmatches (I). submatches (1 )))
Arrindex (I) = "datasource _ (" & objmatches (I). submatches (1 )&")"
Else
Parsetemplate = parsetemplate & arrtemp (I)
End if
Arrtemplate (I) = arrtemp (I)
Next
Set objmatches = nothing
Set objregexp = nothing
End Function
 
Private arrvaluetemplate and arrvalueindex templates cache arrays to reduce resolution time
 
'Parsing Template
Private function parsevaluetemplate (byval stritemtemplate)
Parsevaluetemplate = parsetemplate (stritemtemplate, arrvaluetemplate, arrvalueindex)
End Function
 
Private arrtexttemplate, arrtextindex 'template caches an array to reduce resolution time
 
'Parsing Template
Private function parsetexttemplate (byval stritemtemplate)
Parsetexttemplate = parsetemplate (stritemtemplate, arrtexttemplate, arrtextindex)
End Function

'Initialization
Private sub class_initialize ()
ID _ = "dropdownlist1"
Datavaluefield _ = "{0 }"
Datatextfield _ = "{1 }"
Selectedindex _ =-1
Selectedvalue _ = ""
Islist _ = false
Multiple _ = false
End sub

'Destroy
Private sub class_terminate ()
If not datasource _ is nothing then
Datasource _. Close ()
Set datasource _ = nothing
End if
End sub
 
End Class
%>

There are still many shortcomings. please correct me!

Example:

<! -- # Include virtual = "/asplib/util/configuration. asp" -->
<! -- # Include virtual = "/asplib/util/dataaccess. asp" -->
<! -- # Include virtual = "/asplib/control/dropdownlist. asp" -->

<%
Set objddl = new dropdownlist
Objddl. ID = "dropdownlist1"
Objddl. addheader "select news Classification ",""
Objddl. datasource = new dataaccess. executereader ("select newscategoryid, newscategoryname from news_category ")
Objddl. databind ()
Set objddl = nothing
%>