sql - ComboBox not showing DisplayMember -
i'm trying display question id's in combo box, in order reproduce matching question in text box. rather question id's appearing, receiving 5 question id's:
wcinterface.ucquestions+questionwcinterface.ucquestions+question
my code:
private loaded boolean = false private sub ucquestions_load(byval sender system.object, byval e system.eventargs) handles mybase.load cmbquestion.displaymember = "question_id" cmbquestion.valuemember = "question_id" cmbquestion.datasource = retrievequestions() 'when form loads loaded = true end sub private sub cmbquestion_selectedindexchanged(byval sender system.object, byval e system.eventargs) handles cmbquestion.selectedindexchanged if (loaded) cmbquestion.displaymember = "question_id" cmbquestion.valuemember = "question_id" cmbquestion.datasource = nothing 'resets data source cmbquestion.datasource = retrievequestions() 'when form loads end if end sub public function retrievequestions() list(of question) dim typelist new list(of question) dim str string = "select question_id, question_text question" try using conn new sqlclient.sqlconnection(dbconnection) conn.open() using cmdquery new sqlclient.sqlcommand(str, conn) using drresult sqlclient.sqldatareader = cmdquery.executereader() while drresult.read typelist.add(new question(drresult("question_id"), drresult("question_text"))) end while end using 'automatically closes connection end using end using catch ex exception msgbox("question list exception: " & ex.message & vbnewline & str) end try return typelist end function
i'd appreciate suggestions how display question id's, thankyou
you didn't post question class, displaymember , valuemember fields aren't matching property fields in question class:
it should this:
public class question property questionid integer property questiontext string public sub new(q_id integer, q_text string) questionid = q_id questiontext = q_text end sub end class
then data source properties this:
cmbquestion.displaymember = "questionid" cmbquestion.valuemember = "questionid" cmbquestion.datasource = retrievequestions()
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