Caching Dataset and DataAdapter for ddl

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Caching Dataset and DataAdapter for ddl

Author

Topic

bubberz
Constraint Violating Yak Guru

289 Posts

Posted - 2005-11-27 : 13:12:32

I'm working through the MCAD training, and can't seems to get a dropdownlist to populate from a cached dataset:

**********
Here's the code on the first page:
Private Sub Page_Load(....)
If Not IsPostBack Then
AddtoCache("adptCalls", DA1)
AddtoCache("adptContactTypes", DA2)
AddtoCache("adptContacts", DA3)
'Fill data sets and add them to Cache
DA1.Fill(DsCalls1)
AddtoCache("DSCalls", DsCalls1)
DA2.Fill(DsContactTypes1)
AddtoCache("DSContactTypes", DsContactTypes1)
DA3.Fill(DsContacts1)
AddtoCache("DSContacts", DsContacts1)
End If
End Sub

Sub AddtoCache(ByVal Name As String, ByVal Item As Object)
'if item already in cache, simply return
If Not IsNothing(Cache(Name)) Then Return
'Otherwise cache item for 20min w/ sliding expiration
Cache.Add(Name, Item, Nothing, DateTime.MaxValue, System.TimeSpan.FromMinutes(20), Caching.CacheItemPriority.Default, Nothing)
End Sub

**********
The second page has:
Private Sub Page_Load(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles MyBase.Load
' Get the Cached variables.
adptContacts = Cache("adptContacts")
dsContacts = Cache("dsContacts")
dsContactTypes = Cache("dsContactTypes")
If Not IsPostBack Then
' Bind to data -- populates lists.
drpContactTypes.DataSource = dsContactTypes
drpContactTypes.DataTextField = "ContactType"
drpContactTypes.DataValueField = "ContacTypeID"
drpContactTypes.DataBind()
drpStates.DataBind()
End If
' If there was an unhandled error, display it.
If Session("Error") <> "" Then
litStatus.Text = Session("Error")
' Reset the error message.
Session("Error") = Nothing
End If
End Sub

saglamtimur
Yak Posting Veteran

91 Posts

Posted - 2005-11-27 : 17:11:57

First, dont add dataadapter to cache. Just add DataSet(s). Second, -as I know- cache names are case sensetive. If you add "DSContacts" you must call "DSContacts", not "dsContacts". Third, I see you assign like dsContacts = Cache("dsContacts"). So what it dsContacts? dataset? datatable?. Its name looks like its a dataset but its better you expilictly "Dim" it.

Dim dsContacts as DataSet = Cache("dsContacts").

As I know VB.Net dynamicly convert objects, but Its better to use like

Dim dsContacts as DataSet = Ctype(Cache("dsContacts"),DataSet)

And finally I could see a datasource for drpStates, but you use drpStates.DataBind().

Good Luck

bubberz
Constraint Violating Yak Guru

289 Posts

Posted - 2005-11-28 : 16:23:51

Thanks saglamtimur!

the dropdownlist, drpStates, is from an Array string I have in the page. That works, but thanks for checking on that one.
I'll look into the spelling and let you know!

bubberz
Constraint Violating Yak Guru

289 Posts

Posted - 2005-12-02 : 23:12:57

It was the case sensitive issue for not populating my ddl.

Thanks!

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