I am loading a tiff file into a PictureBox in .NET WinForms.
My users need to be able to zoom in and out of the image, do you have a function for this?
Unfortunately, GroupDocs.Viewer itself does not offer built-in zoom functionality. Additionally, PictureBox controls also lack a native zoom feature. To achieve zooming, you’ll need to implement it within your client-side code.
We have basic Win Forms demo application that can only open files.
Thank you for sending me in the right direction.
I was able to get it working like this:
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Put the picturebox into a Panel (I named mine pnlPictureBox):
a. Open the Form in design mode
b. Cut the PictureBox
c. Add a Panel, set AutoScroll to True
d. Paste the PictureBox into the Panel -
On the PictureBox, set SizeMode = Forms.PictureBoxSizeMode.Zoom
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And here’s the code for zooming in:
Private Sub LoadFile(ByVal fileName As String, PageNumber As Integer)
tiffViewer = New Viewer(fileName)
MemoryPageStreamFactory = New MemoryPageStreamFactory()
jpgViewOptions = New JpgViewOptions(MemoryPageStreamFactory)
tiffViewer.View(jpgViewOptions, PageNumber)
MemoryPageStreamFactory.Stream.Position = 0
pictureBox.Image = System.Drawing.Image.FromStream(MemoryPageStreamFactory.Stream)
' These 2 lines are essential for zooming in/out
pictureBox.Width = pictureBox.Image.Width
pictureBox.Height = pictureBox.Image.Height
End Sub
Private Sub btnLarger_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLarger.Click
pictureBox.Width += pictureBox.Width * 0.25
pictureBox.Height += pictureBox.Height * 0.25
End Sub