topic Re: arc obejcts - string builder in ArcObjects SDK Questions

arc obejcts - string builder

SusanneWagner — Sun, 02 Aug 2015 08:22:36 GMT

Hello,

I'm newbie in vb.net and have question about string builder to show the arcgis layers. (System: ArcGis 10.2, VisualStudio2012) I don't succeed to show the loaded layers in a line of the message box.

Thanks for any help in advance!

code:

Imports ESRI.ArcGIS.Geodatabase Imports ESRI.ArcGIS.Carto Imports ESRI.ArcGIS.ArcMapUI Imports System.Text Public Class LayerLoop2_Button1 Inherits ESRI.ArcGIS.Desktop.AddIns.Button Public Sub New() End Sub Protected Overrides Sub OnClick() AccessLayerViaMxDocument(My.ArcMap.Document) My.ArcMap.Application.CurrentTool = Nothing End Sub Shared Sub AccessLayerViaMxDocument(ByVal pMxDocument As IMxDocument) Dim pMap As IMap Dim pMaps As IMaps = pMxDocument.Maps Dim i As Integer For i = 0 To pMaps.Count - 1 Step i + 1 pMap = pMaps.Item(i) Debug.WriteLine(pMap.Name) MsgBox(pMap.Name) Dim pEnumLayer As IEnumLayer = pMap.Layers(Nothing, True) pEnumLayer.Reset() Dim pLayer As ILayer = pEnumLayer.Next() Dim sb As System.Text.StringBuilder = New System.Text.StringBuilder() While Not pLayer Is Nothing Debug.WriteLine(pLayer.Name) ' Show MessageBox with the name of the layer pLayer = pEnumLayer.Next() sb.Append(pLayer.Name) MsgBox(sb.ToString()) End While

Re: arc obejcts - string builder

DuncanHornby — Mon, 03 Aug 2015 09:34:29 GMT

Susanne,

When you post code you should use the syntax highlighter in the Advance Editor option then >> button. This will make reading your code easier for others and improve your chances of getting an answer. You can go back and edit your question any time.

That being said looking at your code on each iteration of the While loop you append then print sb, so what is not working?

Re: arc obejcts - string builder

SusanneWagner — Mon, 03 Aug 2015 18:37:53 GMT

Hello Duncan,

thank you for your answer! I don't succeed to edit the code again but I will do it with next question! For code above he placement of the message box was wrong. It must be placed outside the loop. At least it works but when I put 4 layers in the arcgis toc there will be showed just 2 layers.....

Re: arc obejcts - string builder

DuncanHornby — Sun, 12 Dec 2021 06:56:21 GMT

Susanne,

The reason you are only seeing 2 layers reported is because the sequence is incorrect your code should be:

Dim pEnumLayer As IEnumLayer = pMap.Layers(Nothing, True)
pEnumLayer.Reset()
Dim pLayer As ILayer = pEnumLayer.Next()
Dim sb As System.Text.StringBuilder = New System.Text.StringBuilder()
While Not pLayer Is Nothing
  sb.Append(pLayer.Name)
  pLayer = pEnumLayer.Next()
End While
MsgBox(sb.ToString())

To understand this you have created an enumerate and get the first layer, as this not nothing it enters the While loop. It appends the name and then gets the next layer. Your original code had the get next layer code before you ever added it to stringbuilder so this is why it skipped a layer name.

Re: arc obejcts - string builder

SusanneWagner — Tue, 04 Aug 2015 16:04:53 GMT

Dear Duncan,

thank you a lot!!! It works perfectly now!!