topic Re: Populate listbox with attributes VB.Net in ArcObjects SDK Questions

Populate listbox with attributes VB.Net

MatthewPeterson — Wed, 15 Dec 2010 09:24:45 GMT

Hi,

I am having trouble trying to populate a listbox with attributes on my vb.net windows form.

My shapefile has two fields, an address number and street name. I need to use a query filter to search for an address number, and then populate my listbox with street names that have the same address number.

I can't seem to get this to work. Any help or pointers in the right direction is greatly appreciated!

Re: Populate listbox with attributes VB.Net

Udaya_BhaskerCheerala — Wed, 15 Dec 2010 11:12:27 GMT

Pass layer index on form load then apply query filter to this layer and add reslult to list box when Find/OK button(assuming on form) is cliked.

Thanks,
Uday

Hi,

I am having trouble trying to populate a listbox with attributes on my vb.net windows form.

My shapefile has two fields, an address number and street name. I need to use a query filter to search for an address number, and then populate my listbox with street names that have the same address number.

I can't seem to get this to work. Any help or pointers in the right direction is greatly appreciated!

Re: Populate listbox with attributes VB.Net

MatthewPeterson — Wed, 15 Dec 2010 12:04:20 GMT

I can set the query filter up to search my attribute fields/select the correct street numbers, but how would I go about selecting the corresponding street names that are contained in a different field?

Also, what is the command for adding attributes to a list box using a query filter- I think this is where I am hung up at.

This is what I have so far, it crashes at:
lstboxStName.Items.Add(pQueryFilter.Values)
__________________________________________________________________

Dim pMxDoc As IMxDocument
pMxDoc = CType(m_app.Document, IMxDocument)
Dim pMap As IMap
pMap = pMxDoc.FocusMap

Dim pFlayer As IFeatureLayer
pFlayer = CType(pMap.Layer(0), IFeatureLayer)
Dim pFDef As IFeatureLayerDefinition
pFDef = pFlayer

Dim pFClass As IFeatureClass
pFClass = pFlayer.FeatureClass

Dim StreetNumber As Integer = txtStNum.Text
Dim pQueryFilter As IQueryFilter
pQueryFilter = New QueryFilter
pQueryFilter.WhereClause = "StreetNum='" & StreetNumber & "'"

lstboxStName.Items.Add(pQueryFilter.Values)
lstboxStName.Refresh()

Re: Populate listbox with attributes VB.Net

SteveFang — Wed, 15 Dec 2010 18:56:34 GMT

Queryfilter actually return a cursor so you are heading down the wrong path.

Try this instead, pretty basic code but hopefully get you in the right direction.

dim pFeaCursor as iFeaturecursor = pFClass.search(pqeryfilter, false)
dim pFeature as iFeature = pFeaCursor.nextfeature
dim streetname as string = ""

do until pfeature is nothing
   streetname = pfeature.value(pfeature.fields.findfield("Name of Street name field"))
   lstboxStName.Items.Add(streetname)
   pfeature = pfeacursor.nextfeature
loop

Re: Populate listbox with attributes VB.Net

MatthewPeterson — Wed, 15 Dec 2010 20:57:22 GMT

Still having trouble with this. Can't seem to get anything to work.

Queryfilter actually return a cursor so you are heading down the wrong path.

Try this instead, pretty basic code but hopefully get you in the right direction.

dim pFeaCursor as iFeaturecursor = pFClass.search(pqeryfilter, false)
dim pFeature as iFeature = pFeaCursor.nextfeature
dim streetname as string = ""

do until pfeature is nothing
   streetname = pfeature.value(pfeature.fields.findfield("Name of Street name field"))
   lstboxStName.Items.Add(streetname)
   pfeature = pfeacursor.nextfeature
loop

Re: Populate listbox with attributes VB.Net

SteveFang — Wed, 15 Dec 2010 22:11:39 GMT

What errors are you encountering in Visual Studio debugger?

Re: Populate listbox with attributes VB.Net

MatthewPeterson — Wed, 15 Dec 2010 22:30:49 GMT

This is what I have, it dies at:
        Dim pFeaCursor As IFeatureCursor = pFeatLayer.Search(pQueryFilter, False)

I believe I need the query filter because I need to use an input box to get a street number the user enters. Then select all the street numbers that match/partially match value. The listbox is then populated with the street names that match/partially match the value in the input box.

I'm stumped...
______________________________________________________________________
Dim pMap As IMap
        Dim pMxDoc As IMxDocument
        Dim pFeatLayer As IFeatureLayer
        Dim pFeatSel As IFeatureSelection
        Dim pQueryFilter As IQueryFilter
        pMxDoc = CType(m_app.Document, IMxDocument)
        pMap = pMxDoc.FocusMap

        ' Find Parcels Layer in TOC
        Dim sLayerName As String
        sLayerName = "Parcels"
        Dim i As Integer
        For i = 0 To pMap.LayerCount - 1
            If pMap.Layer(i).Name = sLayerName Then
                pFeatLayer = pMap.Layer(i)
                Exit For
            End If
        Next i

        'Check to See if Parcels is in TOC
        If pFeatLayer Is Nothing Then
            MsgBox("Please add the parcel shapefile to ArcMap")
            Exit Sub
        End If

        'Get Parcel ID
        Dim StNum As Integer
        StNum = txtStNum.Text

        ' Create the query filter
        pQueryFilter = New QueryFilter
        pQueryFilter.WhereClause = "StreetNum='" & StNum & "'"

        Dim pFeaCursor As IFeatureCursor = pFeatLayer.Search(pQueryFilter, False)
        Dim pFeature As IFeature = pFeaCursor.NextFeature
        Dim streetname As String = ""

        Do Until pFeature Is Nothing
            streetname = pFeature.Value(pFeature.Fields.FindField("StreetName"))
            lstboxStName.Items.Add(streetname)
            pFeature = pFeaCursor.NextFeature
        Loop

    End Sub

What errors are you encountering in Visual Studio debugger?

Re: Populate listbox with attributes VB.Net

SteveFang — Wed, 15 Dec 2010 22:50:38 GMT

Your StNum variable is declared as integer yet in your queryfilter you are searching for a sting. Is your street number field a numeric or string field? If numeric then remove the single quote from your whereclause. Plus your street name field in your code is "Street Na me". I don't if you intend to have a space or not. Maybe your code is not working due to nothing returning from the search.