Apologies for not getting this published sooner... Between getting ready to move houses and my normal level of laziness and procrastination, I haven't done it. It also took some Googling to figure out
how to include code in a BlogSpot post. Enough
whinging, here's the code for the OPC (
Open Packaging Convention) class I did.
By the way, here is my
DevX article on the same subject that got published recently.
Here is the code to create a package:
'Open the package
Using package As Package = package.Open("c:\Example.zip", IO.FileMode.OpenOrCreate)
'Create the uri for the text file
Dim uri As New Uri("/TextFiles/MyTextFile.Text", UriKind.RelativeOrAbsolute)
'Create the part for the text file
Dim part As PackagePart = package.CreatePart(uri, System.Net.Mime.MediaTypeNames.Text.Plain)
'Get the stream for the part
Using stream As Stream = part.GetStream()
'This is the text we'll put in the part
Dim myText As String = "This is an ugly picture of a flower - Roanoke!"
'We need to get the string into a byte array to make it easy to write to the part stream
Dim buffer As Byte() = System.Text.ASCIIEncoding.ASCII.GetBytes(myText)
'Write to the part stream
stream.Write(buffer, 0, buffer.Length)
End Using
'This is the uri for the flower
Dim uri2 As New Uri("/Images/Flower.jpg", UriKind.RelativeOrAbsolute)
'Create the part for the image
Dim part2 As PackagePart = package.CreatePart(uri2, _
System.Net.Mime.MediaTypeNames.Image.Jpeg)
'Get the stream for this part
Using stream As Stream = part2.GetStream()
'Read the data from the file
Dim buffer As Byte() = File.ReadAllBytes("c:\Flower.jpg")
'write the data to the part
stream.Write(buffer, 0, buffer.Length)
End Using
'Create a relationship between the parts
Dim relationship As PackageRelationship = _
part2.CreateRelationship(part.Uri, TargetMode.Internal, "flower_to_text")
End Using
And here is the code to read that package:
'Create the package
Using package As Package = package.Open("c:\Example.zip", IO.FileMode.Open)
'We know the Uri for the flower, so let's start there
Dim flowerUri As New Uri("/Images/Flower.jpg", UriKind.RelativeOrAbsolute)
'Get the part using the uri we just set up
Dim flowerPackagePart As PackagePart = _
package.GetPart(flowerUri)
'Create a relationship from the
Dim relationships As PackageRelationshipCollection = _
flowerPackagePart.GetRelationshipsByType("flower_to_text")
'Get the first relationship (in real code, we would want some error checking here)
Dim relationship As PackageRelationship = _
relationships(0)
'Get the part from the relationship (once again, this would need some
' error protection because in a real world app this part might not exist anymore).
Dim textPart As PackagePart = package.GetPart(relationship.TargetUri)
'Get the stream
Using stream As Stream = textPart.GetStream()
'Create a buffer
Dim buffer(stream.Length) As Byte
'Read the stream
stream.Read(buffer, 0, stream.Length)
'Read the text
Dim myText As String = System.Text.ASCIIEncoding.ASCII.GetString(buffer)
'Show the text (the crowd should go wild here)
MessageBox.Show(myText)
End Using
End Using
End Sub
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