Mohamed,
Crosshair is used to show the x & y axis values at the current mouse co-ordinates or the nearest data points. It is not possible to drag and drop Crosshair. However, you can achieve drag and drop functionality with striplines. Please take a look at this jsfiddle.
You can accept input value from user and place a stripline at specified position. Please take a look at this jsfiddle.
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Priyanka M S
Team CanvasJS