I have polygon feature and I want to reshape this feature how can I reshape this polygon feature ?
Are you wanting an interactive experience? We don't yet have a "sketch layer", but plan on having something similar at a future release. In the meantime, you could just take the geometry of the feature, create a graphic using that geometry, allow the user to click and edit the graphic, then once they are done, update the feature's geometry with the graphic's geometry.
Are there any examples about this ?
Not exactly, but you could probably use the "Difference Online" geometry sample in the QML Sample App to imitate a sketch. That is probably the best place to start.
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