CODEWITHSUNDEEP
vb.netimagemetadataclipboard
Brian Mulcahy
Brian Mulcahy

Reputation: 1503

VB.NET: Preserve image metadata when moved to clipboard as an image

Visual Studio 2010, .NET 4, VB.NET

Hello,

I am writing a little program to convert LaTeX snippets to images which can be pasted into whatever program one can paste images into. It's working alright but the next obvious step is to include the source LaTeX code as a piece of metadata in the image so that the results can be modified without having to retype everything.

I have succeeded in adding a title PropertyItem with the latex encoded as an ASCII byte array as its value (id=800, type=2, value=System.Text.Encoding.ASCII.GetBytes(codestring)). I verify that the PropertyItem is really there before trying to put the image on the clipboard.

Then I do Clipboard.SetImage(myImage). The result is all of the PropertyItems are removed (my title plus anything else that was there)! I check this by doing MsgBox(Clipboard.GetImage.PropertyItems.Count.ToString) which gives zero.

This makes me very sad. Anyone know what's up?

Thanks in advance!
Brian

Update: I have figured out how to move the image onto the clipboard and then back off while preserving the PropertyItems like so:

Format = DataFormats.GetFormat(GetType(Image).FullName)
Dim dataObject As New DataObject
dataObject.SetData(Format.Name, image)
Clipboard.SetDataObject(dataObject)

Dim copiedImage As Image = CType(Clipboard.GetDataObject.GetData(Format.Name), Image)

This way, the copiedImage has the same PropertyItems as the original. However, new problem:

Other programs don't recognize what's on the clipboard as an image anymore, which defeats the whole purpose. I.e., if I put an image on the clipboard this way, when I try pasting into some context that accepts pasted images, nothing happens.

What to do?!

Upvotes: 2

Views: 874

Answers (2)

xpda
xpda

Reputation: 15813

I believe the Windows clipboard image has no metadata. If you change the format of the image to add metadata, it is no longer a clipboard image. If the other programs can accept it, you could copy and paste the image file (instead of the image) to the clipboard, and the metadata will of course be intact when it's read by the target app.

Upvotes: 1

competent_tech
competent_tech

Reputation: 44941

Have you tried Clipboard.SetData or Clipboard.SetDataObject? SetImage only copies the image in bitmap format, so I am not surprised that it strips the property items. You might try:

Clipboard.SetData(DataFormats.EnhancedMetafile, myImage)

or

Clipboard.SetData(DataFormats.MetafilePict, myImage)

Upvotes: 0

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