You can use a FeatureCursor to grab the field value. The code below is looking at a selected record. Then, just assign your strValue to your text box.
Dim hook As Object
Dim App as IApplication = CType(hook, IApplication)
MxDoc = CType(App.Document, IMxDocument)
Dim pMap As IMap
pMap = MxDoc.FocusMap
Dim pEnumLayer As IEnumLayer
pEnumLayer = pMap.Layers
pEnumLayer.Reset()
Dim pLayer As ILayer
pLayer = pEnumLayer.Next
Dim pFLayer As IFeatureLayer
Do While Not pLayer Is Nothing
If pLayer.Name = strLayerName And TypeOf pLayer Is IFeatureLayer Then ' Substitute your real layer name
pFLayer = TryCast(pLayer, IFeatureLayer)
Exit Do
End If
pLayer = pEnumLayer.Next
Loop
If pFLayer Is Nothing Then
MsgBox("No GetFeatuerValue Layer Found")
Exit Function
End If
Dim pFSel As IFeatureSelection
pFSel = pFLayer
Dim pSelSet As ESRI.ArcGIS.Geodatabase.ISelectionSet2
pSelSet = pFSel.SelectionSet
If pSelSet.Count < 1 Then
MsgBox("No Features Selected")
Return Nothing
End If
Dim pFCursor As ESRI.ArcGIS.Geodatabase.IFeatureCursor = Nothing
pSelSet.Search(Nothing, False, pFCursor)
Dim pFeature As IFeature
pFeature = pFCursor.NextFeature ' Get First Feature
If pFeature Is Nothing Then
MsgBox("No Features Selected!") ' Just in case, but probably already taken care of earlier
Return Nothing
End If
Dim lFIndex As Long
Dim strValue As String
lFIndex = pFCursor.FindField("MYField") ' Replace with your field name
If lFIndex > -1 Then
Dim fValue As String ' Substute the correct data type to match the field type
Do While Not pFeature Is Nothing
fValue = pFeature.Value(lFIndex)
' Do something with the value stored in fValue
pFeature = pFCursor.NextFeature
strValue = fValue
Loop
End If
Me.txtValue.Text = strValue
Marshal.ReleaseComObject(pFCursor)
