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EnumGeoKeys(Stream,Int32) Method
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Leadtools.Codecs Namespace > RasterCodecs Class > EnumGeoKeys Method : EnumGeoKeys(Stream,Int32) Method



stream
A Stream containing the input image data.
pageNumber
1-based index of the page from which to enumerate the tags.
Enumerates all the GeoKeys in a Geo TIFF stream.

Syntax

Visual Basic (Declaration) 
Public Overloads Sub EnumGeoKeys( _
   ByVal stream As Stream, _
   ByVal pageNumber As Integer _
)
Visual Basic (Usage)Copy Code
Dim instance As RasterCodecs
Dim stream As Stream
Dim pageNumber As Integer
 
instance.EnumGeoKeys(stream, pageNumber)
C# 
public void EnumGeoKeys( 
   Stream stream,
   int pageNumber
)
C++/CLI 
public:
void EnumGeoKeys( 
   Stream^ stream,
   int pageNumber
)

Parameters

stream
A Stream containing the input image data.
pageNumber
1-based index of the page from which to enumerate the tags.

Example

This example will show all the geo keys in the given file then loads them and adds them to a destination file

Visual BasicCopy Code
Private myGeoKeys As RasterCollection(Of RasterTagMetadata)
Private geoKeyFileName As String

Private Sub EnumGeoKeysExample(ByVal srcFileName As String, ByVal destFileName As String)
   RasterCodecs.Startup()
   Dim codecs As RasterCodecs = New RasterCodecs()

   geoKeyFileName = srcFileName
   myGeoKeys = New RasterCollection(Of RasterTagMetadata)()

   AddHandler codecs.GeoKeyFound, AddressOf codecs_GeyKeyFound
   codecs.EnumGeoKeys(srcFileName, 1)
   RemoveHandler codecs.GeoKeyFound, AddressOf codecs_GeyKeyFound

   ' We read all the tags now, save them to the file
   Console.WriteLine("{0} GeoKeys read, saving them to the destination file", myGeoKeys.Count)
   codecs.WriteGeoKeys(destFileName, 1, myGeoKeys)

   ' Clean up
   codecs.Dispose()
   RasterCodecs.Shutdown()
End Sub

Private Sub codecs_GeyKeyFound(ByVal sender As Object, ByVal e As CodecsEnumGeoKeysEventArgs)
   Console.Write("GeoKey: Id={0}, Count={1}, Type={2}, DataLength={3}, Data=", e.Id, e.Count, e.MetadataType, e.DataLength)

   ' Load this GeoKey
   Dim codecs As RasterCodecs = TryCast(sender, RasterCodecs)
   Dim geoKey As RasterTagMetadata = codecs.ReadGeoKey(geoKeyFileName, 1, e.Id)
   Dim data As Byte() = geoKey.GetData()
   Dim i As Integer = 0
   Do While i < data.Length
      Console.Write("{0:X} ", data(i))
      i += 1
   Loop
   Console.WriteLine()

   ' Add it to our collection
   myGeoKeys.Add(geoKey)
End Sub
C#Copy Code
RasterCollection<RasterTagMetadata> myGeoKeys; 
string geoKeyFileName; 
 
void EnumGeoKeysExample(string srcFileName, string destFileName) 
{ 
   RasterCodecs.Startup(); 
   RasterCodecs codecs = new RasterCodecs(); 
 
   geoKeyFileName = srcFileName; 
   myGeoKeys = new RasterCollection<RasterTagMetadata>(); 
 
   codecs.GeoKeyFound += new EventHandler<CodecsEnumGeoKeysEventArgs>(codecs_GeyKeyFound); 
   codecs.EnumGeoKeys(srcFileName, 1); 
   codecs.GeoKeyFound -= new EventHandler<CodecsEnumGeoKeysEventArgs>(codecs_GeyKeyFound); 
 
   // We read all the tags now, save them to the file 
   Console.WriteLine("{0} GeoKeys read, saving them to the destination file", myGeoKeys.Count); 
   codecs.WriteGeoKeys(destFileName, 1, myGeoKeys); 
 
   // Clean up 
   codecs.Dispose(); 
   RasterCodecs.Shutdown(); 
} 
 
void codecs_GeyKeyFound(object sender, CodecsEnumGeoKeysEventArgs e) 
{ 
   Console.Write("GeoKey: Id={0}, Count={1}, Type={2}, DataLength={3}, Data=", e.Id, e.Count, e.MetadataType, e.DataLength); 
 
   // Load this GeoKey 
   RasterCodecs codecs = sender as RasterCodecs; 
   RasterTagMetadata geoKey = codecs.ReadGeoKey(geoKeyFileName, 1, e.Id); 
   byte[] data = geoKey.GetData(); 
   for(int i = 0; i < data.Length; i++) 
      Console.Write("{0:X} ", data[i]); 
   Console.WriteLine(); 
 
   // Add it to our collection 
   myGeoKeys.Add(geoKey); 
}

Remarks

To enumerate all the keys stored in a disk file, use EnumGeoKeys.

For multipage Geo TIFF files, you can enumerate the GeoKeys from a particular page. Specify the page number whose GeoKeys to enumerate.

The GeoKeyFound event is called for each GeoKey value stored in the three standard Geo TIFF tags (34735, 34736 and 34737). For enumerating the other standard Geo TIFF data stored as separate tags, you can use EnumTags. Or, you can call ReadTag for each of these tags (since there are not that many of them to warrant the use of EnumTags).

For more information, refer to Implementing GeoKeys (GeoTIFF tags).

Requirements

Target Platforms: Microsoft .NET Framework 3.0, Windows XP, Windows Server 2003 family, Windows Server 2008 family

See Also