From NSB App Studio
Jump to navigation Jump to search
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.



The Signature control lets you capture signatures and drawings. You can save and display the results as a Base64 string.

This control is based on an HTML Canvas element: the properties and methods of the PictureBox will also work on a Signature control.

Properties and Methods

Standard properties are supported.

clear() Clear the current contents.
getContext("2d") Gets the drawing context. Returns the object that the PictureBox Context functions use. "2d" is currently the only valid argument.
lineColor Sets the color of the line. Default is a deep blue.
lineWidth Sets the width of the line. Default is 1.5 pixels.
toDataURL(type) Returns the current picturebox in a Base64 string image. If type is not specified, it is in PNG format. Type can also be "image/jpeg" or "image/gif".


Events are handled by the control itself.


The follow code initializes the signature control and shows how to save and clear it.

Function btnSave_onclick()
  'Get the image in a string which can be saved.
  Dim imageStr = Signature1.toDataURL("image/png")
  'display the string in an Image control.
  Image1.src = imageStr
End Function

Function btnClear_onclick()
  Dim context = Signature1.getContext("2d");
  context.clearRect(0, 0, Signature1.width, Signature1.height) 
End Function


Related Items