Display Selected Features Attributes in User Form

Question

I'm trying to convert my ArcGIS 9.3 code to ArcGIS 10 via Visual Basic 2008 Express; however, I'm having a couple issues.

The goal is for a user to select a feature in ArcMap, click on this custom button, and a user form appears displaying attribute information of the selected feature. The code worked great in 9.3, but not in 10.

Currently, I can get the user form to open by itself...but if a user selects a feature and clicks the button it crashes ArcMap.

**User Form Code:**
 Open User Form
 Public Class TransLineEdit
 Inherits ESRI.ArcGIS.Desktop.AddIns.Button
 Dim pForm As New frmEdit
 Protected Overrides Sub OnClick()
 Try
 pForm.Show()
 Catch ex As Exception
 System.Windows.Forms.MessageBox.Show(ex.ToString, "OnClick")
 End Try
 End Sub
 End Class
 **User Form Code:**
 Imports ESRI.ArcGIS.ArcMapUI
 Imports ESRI.ArcGIS.Carto
 Imports ESRI.ArcGIS.Geodatabase
 Imports ESRI.ArcGIS.Geometry
 Imports ESRI.ArcGIS.ArcMap
 Imports ESRI.ArcGIS.DataManagementTools
 Imports ESRI.ArcGIS.Desktop
 Imports ESRI.ArcGIS.Editor
 Imports ESRI.ArcGIS.Framework
 Public Class frmLineSelectAttribute
'Declare variables that are used all thru the application
Public pMxDoc As IMxDocument
Public pMap As ESRI.ArcGIS.Carto.IMap
Public pEditor As IEditor
Public Application As IAppROT
Private Sub cmdCancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdCancel.Click
 'Kill form
 Me.Close()
 'Clear selected features
 'Dim pActiveView As ESRI.ArcGIS.Carto.IActiveView
 'pActiveView = pMap
 'pMap.ClearSelection()
 'pActiveView.Refresh()
End Sub
Shared Function AccessLayersData(ByVal pLayer As ESRI.ArcGIS.Carto.ILayer) As IFeatureClass
 Dim pFeatureLayer As ESRI.ArcGIS.Carto.IFeatureLayer = pLayer
 If Not pFeatureLayer Is Nothing Then
 Return pFeatureLayer.FeatureClass
 Else
 Return Nothing
 End If
End Function
Private Sub UserForm_Initialize()
 'Get Improvement Projects FeatureLayer
 Dim pFeatLyr As ESRI.ArcGIS.Carto.IFeatureLayer
 pFeatLyr = GetLayerByTOC("TransportationImprovementProjects_Lines")
 'Get selected feature (only one)
 Dim pFeat As IFeature
 pFeat = GetSelFeat(pFeatLyr)
 'Populate form controls with feature's attribute values
 txtPrjYear.Text = pFeat.Value(pFeat.Fields.FindField("YEAR"))
 txtPrjType.Text = pFeat.Value(pFeat.Fields.FindField("PROJECTYPE"))
 txtAgency.Text = pFeat.Value(pFeat.Fields.FindField("AGENCY"))
 txtLocation.Text = pFeat.Value(pFeat.Fields.FindField("LOCATION"))
 txtDescrip.Text = pFeat.Value(pFeat.Fields.FindField("DESCRIPTION"))
 txtCost.Text = pFeat.Value(pFeat.Fields.FindField("COST"))
 txtDate.Text = pFeat.Value(pFeat.Fields.FindField("DATEEDITED"))
 txtUser.Text = pFeat.Value(pFeat.Fields.FindField("USEREDITED"))
 'Dim pDoc As IMxDocument
 'Dim pItem As ICommandItem
 'pItem = Project.ThisDocument.CommandBars.Find(arcid.Query_ZoomToSelected)
 'pItem.Execute()
 'pDoc.ActiveView.Refresh()
End Sub
Public Function GetSelFeat(ByVal pFeatLyr As ESRI.ArcGIS.Carto.IFeatureLayer) As IFeature
 'Gets selected feature from feature layer and returns feature
 'Call this function only when you are sure that only one feature is selected
 'Initialize the required variables
 Call Initialize()
 Dim pFeatSel As ESRI.ArcGIS.Carto.IFeatureSelection
 pFeatSel = pFeatLyr
 Dim pSelectionSet As ISelectionSet
 pSelectionSet = pFeatSel.SelectionSet
 pSelectionSet.Search(Nothing, True, pFeatSel)
 'Return the selected feature
 GetSelFeat = pFeatSel.NextFeature
End Function
Public Sub Initialize()
 'Initalize global variables
 pMxDoc = Application.Document
 pMap = pMxDoc.FocusMap
 'Instantiate the editor
 pEditor = Application.FindExtensionByName("ESRI Object Editor")
End Sub
Public Function GetLayerByTOC(ByVal lyrName As String) As ESRI.ArcGIS.Carto.IFeatureLayer
 'This function finds a feature layer based on its TOC Name
 Call Initialize()
 Dim lyrCntr As Integer
 Dim pFeatLyr As ESRI.ArcGIS.Carto.IFeatureLayer
 For lyrCntr = 0 To pMap.LayerCount - 1
 'Ensure that the layer is valid
 If pMap.Layer(lyrCntr).Valid = True Then
 'Ensure that the layer is a feature layer
 If TypeOf pMap.Layer(lyrCntr) Is ESRI.ArcGIS.Carto.IFeatureLayer Then
 pFeatLyr = pMap.Layer(lyrCntr)
 If UCase(pMap.Layer(lyrCntr).Name) = UCase(lyrName) Then
 GetLayerByTOC = pFeatLyr
 Exit Function
 End If
 End If
 End If
 Next lyrCntr
 'Layer not found. Show a message
 MsgBox("Layer " & lyrName & " not found !", vbCritical, "Error")
End Function
 End Class

• artwork21: Was the 9.3 version in VBA? What is the error, and what line does it occur on? You may want to include some Try Catch wrappers around your code.

Answer 1

Here are some suggestions:

1. Include some additional try catch statements into your code so you can identifly what line is giving you the error.

   Try
    'Your code here
   Catch ex As Exception
    MessageBox.Show("Caught an unspecified error in the calling code: " & vbCrLf & ex.ToString)
   

   End Try

2. May want to check that Intialize is a form event, not sure in vs 08, but in vs 10 it is not.

3. You will have to hook your vs project to the ArcMap application, eg.

    m_App = CType(hook, IApplication)
    m_MxDoc = CType(m_App.Document, IMxDocument)
    m_mxDocument = CType(m_App.Document, MxDocument)
    m_map = CType(m_MxDoc.FocusMap, Map)
   

• Phil Davies: Thanks, artwork21..I ended up scratching my code and starting again from the beginning and got it to work. However, I can not get one of my previous functions to work correctly. Before users could change the attribute data that appeared, make changes, and then click a button to save the changes. Any thoughts on starting an editing session and saving changes on a click event?
• artwork21: @Phil Davies, To work with the editor take a look at this link, help.arcgis.com/en/sdk/10.0/arcobjects_net/conceptualhelp/…
• AHigh: Here is some further documentation on using an Update Cursor as opposed to an edit session if you are updating/modifying the attributes of features. help.arcgis.com/en/sdk/10.0/arcobjects_net/conceptualhelp/…