Public Property Tags As Boolean

Visual Basic (Usage)	Copy Code
Dim instance As CodecsLoadOptions Dim value As Boolean   instance.Tags = value   value = instance.Tags

public bool Tags {get; set;}

public:
property bool Tags {
   bool get();
   void set (bool value);
}

Return Value

This example will browse to a file and load it along with any tags, geo-keys and comments found.

Visual Basic

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Public Sub MetadataAutoLoadExample()    ' Prompt the user for an image file    Dim imageFileName As String    Using dlg As New OpenFileDialog()       dlg.Title = "Browse to file to load its meta data"       dlg.Filter = "All Files|*.*"       dlg.InitialDirectory = "C:\Users\Public\Documents\LEADTOOLS Images"       If dlg.ShowDialog() = DialogResult.OK Then          imageFileName = dlg.FileName       Else          Return       End If    End Using    ' Initialize LEADTOOLS    RasterCodecs.Startup()    Using codecs As New RasterCodecs()       Dim loadOptions As CodecsLoadOptions = codecs.Options.Load       ' Make sure auto-loading of markers is turned off, otherwise,       ' markers take precedence over loading the other metadata       loadOptions.Markers = False       ' Automatically load any tags, comments and geokeys found in this file       loadOptions.Tags = True       loadOptions.Comments = True       loadOptions.GeoKeys = True       ' Now load the image       Using image As RasterImage = codecs.Load(imageFileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, 1)          Dim txtFileName As String = Path.Combine( _             Path.GetDirectoryName(imageFileName), _             Path.GetFileNameWithoutExtension(imageFileName) + "_metadata.txt")          Using writer As StreamWriter = File.CreateText(txtFileName)             ' Show its tags             ShowTags(writer, "Tags", image.Tags)             ' Show its comments             ShowComments(writer, image.Comments)             ' Show its geo keys (tags and geokeys use the same data type)             ShowTags(writer, "GeoKeys", image.GeoKeys)          End Using          ' Show the text file we created          System.Diagnostics.Process.Start(txtFileName)       End Using    End Using    RasterCodecs.Shutdown() End Sub Private Shared Sub ShowTags(ByVal writer As StreamWriter, ByVal name As String, ByVal tags As RasterCollection(Of RasterTagMetadata))    writer.WriteLine("{0}:", name)    For Each tag As RasterTagMetadata In tags       writer.WriteLine("Id: 0x{0}, data length: {1}", tag.Id.ToString("X"), tag.GetData().Length)    Next    writer.WriteLine() End Sub Private Shared Sub ShowComments(ByVal writer As StreamWriter, ByVal comments As RasterCollection(Of RasterCommentMetadata))    writer.WriteLine("Comments:")    For Each comment As RasterCommentMetadata In comments       writer.WriteLine("Type: 0x{0}, data length: {1}", comment.Type, comment.GetData().Length)    Next    writer.WriteLine() End Sub

C#

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public void MetadataAutoLoadExample()  {     // Prompt the user for an image file     string imageFileName;     using(OpenFileDialog dlg = new OpenFileDialog())     {        dlg.Title = "Browse to file to load its meta data";        dlg.Filter = "All Files|*.*";        dlg.InitialDirectory = @"C:\Users\Public\Documents\LEADTOOLS Images";        if(dlg.ShowDialog() == DialogResult.OK)           imageFileName = dlg.FileName;        else           return;     }       // Initialize LEADTOOLS     RasterCodecs.Startup();     using(RasterCodecs codecs = new RasterCodecs())     {        CodecsLoadOptions loadOptions = codecs.Options.Load;          // Make sure auto-loading of markers is turned off, otherwise,        // markers take precedence over loading the other metadata        loadOptions.Markers = false;          // Automatically load any tags, comments and geokeys found in this file        loadOptions.Tags = true;        loadOptions.Comments = true;        loadOptions.GeoKeys = true;          // Now load the image        using(RasterImage image = codecs.Load(imageFileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, 1))        {           string txtFileName = Path.Combine(              Path.GetDirectoryName(imageFileName),              Path.GetFileNameWithoutExtension(imageFileName) + "_metadata.txt");             using(StreamWriter writer = File.CreateText(txtFileName))           {              // Show its tags              ShowTags(writer, "Tags", image.Tags);                // Show its comments              ShowComments(writer, image.Comments);                // Show its geo keys (tags and geokeys use the same data type)              ShowTags(writer, "GeoKeys", image.GeoKeys);           }             // Show the text file we created           System.Diagnostics.Process.Start(txtFileName);        }     }     RasterCodecs.Shutdown();  }    private static void ShowTags(StreamWriter writer, string name, RasterCollection<RasterTagMetadata> tags)  {     writer.WriteLine("{0}:", name);       foreach(RasterTagMetadata tag in tags)     {        writer.WriteLine("Id: 0x{0}, data length: {1}", tag.Id.ToString("X"), tag.GetData().Length);     }       writer.WriteLine();  }    private static void ShowComments(StreamWriter writer, RasterCollection<RasterCommentMetadata> comments)  {     writer.WriteLine("Comments:");       foreach(RasterCommentMetadata comment in comments)     {        writer.WriteLine("Type: 0x{0}, data length: {1}", comment.Type, comment.GetData().Length);     }       writer.WriteLine();  }

When the value of the Tags property is set to true, any subsequent load operation performed by this RasterCodecs object will automatically try to load all the tags found in the file and store them in the RasterImage.Tags collection of the result image.

Internally, the RasterCodecs object will call RasterCodecs.TagsSupported on the image and only tries to load the tags if the value returned was true.

When loading more than one page from a multi-page file, only the tags found in the first page will be automatically loaded when the value of this property is set to true. To manually load all the tags in any page, use RasterCodecs.ReadTags(String,Int32).

You must set the value of the Markers property to false to enable automatically loading the tags. If the value of both Markers and Tags is set to true, then the markers will take take precedence and no tags will be loaded.

Note that any load method that uses tiles, offset or resizing will not load any file metadata automatically regardless of the value of this property.

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

Reference