Databases
StackOverflow2013
Postsdbo
POC# to VB.NET Conversion (Google Polyline Algorithm Decoder)
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POC# to VB.NET Conversion (Google Polyline Algorithm Decoder)
    primarykey
    data
    text
    <p>I have some C# code that decodes map paths encoded using Google's polyline algorithm and am trying to convert it to VB.NET.</p> <p>Here's the C# code, which works fully:</p> <pre><code>Collection&lt;Double&gt; decodePolyline(string polyline) { if (polyline == null || polyline == "") return null; char[] polylinechars = polyline.ToCharArray(); int index = 0; Collection&lt;Double&gt; points = new Collection&lt;Double&gt;(); int currentLat = 0; int currentLng = 0; int next5bits; int sum; int shifter; while (index &lt; polylinechars.Length) { // calculate next latitude sum = 0; shifter = 0; do { next5bits = (int)polylinechars[index++] - 63; sum |= (next5bits &amp; 31) &lt;&lt; shifter; shifter += 5; } while (next5bits &gt;= 32 &amp;&amp; index &lt; polylinechars.Length); if (index &gt;= polylinechars.Length) break; currentLat += (sum &amp; 1) == 1 ? ~(sum &gt;&gt; 1) : (sum &gt;&gt; 1); //calculate next longitude sum = 0; shifter = 0; do { next5bits = (int)polylinechars[index++] - 63; sum |= (next5bits &amp; 31) &lt;&lt; shifter; shifter += 5; } while (next5bits &gt;= 32 &amp;&amp; index &lt; polylinechars.Length); if (index &gt;= polylinechars.Length &amp;&amp; next5bits &gt;= 32) break; currentLng += (sum &amp; 1) == 1 ? ~(sum &gt;&gt; 1) : (sum &gt;&gt; 1); points.Add(Convert.ToDouble(currentLat) / 100000.0); points.Add(Convert.ToDouble(currentLng) / 100000.0); } return points; } </code></pre> <p>Here's the VB.NET code- works for the longitudes but not latitudes.</p> <pre><code>Public Function decodePolyline(ByVal polyline As String) As Collection(Of Double) If polyline Is Nothing OrElse polyline = "" Then Return Nothing Dim polylinechars As Char() = polyline.ToCharArray() Dim points As New Collection(Of Double) Dim currentLat As Integer = 0 Dim currentLng As Integer = 0 Dim next5bits As Integer Dim sum As Integer Dim shifter As Integer For index As Integer = 0 To polylinechars.Length - 1 'calculate next latitude sum = 0 shifter = 0 Do index += 1 next5bits = AscW(polylinechars(index)) - 63 sum = sum Or (next5bits And 31) &lt;&lt; shifter shifter += 5 Loop While next5bits &gt;= 32 AndAlso index &lt; polylinechars.Length If index &gt;= polylinechars.Length Then Exit For End If currentLat += If((sum And 1) = 1, Not (sum &gt;&gt; 1), (sum &gt;&gt; 1)) 'calculate next longitude sum = 0 shifter = 0 Do index += 1 next5bits = AscW(polylinechars(index)) - 63 sum = sum Or (next5bits And 31) &lt;&lt; shifter shifter += 5 Loop While next5bits &gt;= 32 AndAlso index &lt; polylinechars.Length If index &gt;= polylinechars.Length AndAlso next5bits &gt;= 32 Then Exit For End If currentLng += If((sum And 1) = 1, Not (sum &gt;&gt; 1), (sum &gt;&gt; 1)) points.Add(Convert.ToDouble(currentLat) / 100000.0) points.Add(Convert.ToDouble(currentLng) / 100000.0) Next Return points End Function </code></pre> <p>What's missing?</p> <p>EDIT: Resolved the issue (corrected code in my answer below, which I can't select as an answer for 2 more days).</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USamb9800
    1. USamb9800
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POC# to VB.NET Conversion (Google Polyline Algorithm Decoder)
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POC# to VB.NET Conversion (Google Polyline Algorithm Decoder)
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POC# to VB.NET Conversion (Google Polyline Algorithm Decoder)
      1. This table or related slice is empty.
      1. VTUpMod
    1. CO(deleted my answer, as I don't think it was helping and my VB has degenerated to read-only, so I can't fix it by glance alone)
      singulars
      1. POC# to VB.NET Conversion (Google Polyline Algorithm Decoder)
      1. USMarc Gravell
    2. COIn what way it does not work? Does it compile? Shows wrong results, different from the C# version?
      singulars
      1. POC# to VB.NET Conversion (Google Polyline Algorithm Decoder)
      1. UStiago2014
    3. COGives incorrect output for the latitudes.
      singulars
      1. POC# to VB.NET Conversion (Google Polyline Algorithm Decoder)
      1. USamb9800
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload