We have recently implemented the Signature control into our Web Forms application using the latest version of Telerik UI Controls for Asp.Net Ajax.

We are having an issue where if the signature control isn’t in the main focus when it loads (for example the control is in a tab that isn't initially the main focus) - the signature stroke is distorted.

In addition, when you maximize the signing area - it has the same distorted view.

Initially empty Signature has no value -> signatureObject.value() returns undefined. When the control is focused it gets a default value representing the blank background of the signature pad.

Validating the Signature based on its value gets quite complex as it requires considering this default base64string.

It would be great if the control would provide functionality to validate for mandatory user input

If one wants to read the resulting signature server-side (after a button-click / form submission), one kind of has to work with a lot of javascript and hidden input fields to transfer the base64-encoded png towards the server. It would be way nicer if you could provide the content of the signature as a server-side property of the RadSignature-control (during post-back).

If you paint a stroke on the canvas, then "maximize" the RadSignature-control (effectively zooming in on the control) and then paint a second stroke, you'll see that those strokes will have a different line width; the second one being bigger.

If you repeatedly maximize/minimize the RadSignature control and draw a stroke each time on the bottom of the canvas, then the resulting image will get distorted.

If one opens a dialog/window containing a RadSignature-control and resizes the dialog (e.g. make it twice as large) then the position of the cursor on the canvas does not match the position of the strokes anymore. Painting in the top-left corner is sort of okay/close, but the further one moves the cursor towards the bottom-right, the bigger the offset will be.

There's no event to hook in case of a reset; therefore I cannot detect resets. Currently, the change event is not firing when the Signature is cleared.

Would it be possible to include an additional button with a feature that allows a user to Type their signature (e.g., like in MS Paint, you can still type and it saves as an image).

This would be beneficial for people who are signing from a computer rather than a tablet or phone device.

The following JavaScript error is thrown when RadSignature is used along with asp:ScriptManager:

Sys.InvalidOperationException: '_uniqueId' is not a property or an existing field.