Ugui exercise (4) draggable object

1. Steps

To listen to the drag event of the UI, We need to write a little bit of code.

1. Create a panel and set the size to 100,100)

2. Create the draggableobjectscene. CS script.

3. Bind the script to the Panel.

4. The script content is as follows:

Using unityengine; using system. collections; using unityengine. ui; using unityengine. eventsystems; public class draggableobjectscene: monobehaviour, idraghandler, ipointerdownhandler, ipointeruphandler {// drag event, set the target location to public void ondrag (pointereventdata eventdata) {getcomponent <recttransform> (). invalid. set (0, 0); transform. position = input. mouseposition;} public void onpointerdown (pointereventdata eventdata) {// narrow down transform. localscale = new vector3 (0.7f, 0.7f, 0.7f);} public void onpointerup (pointereventdata eventdata) {// normal transform size. localscale = new vector3 (1f, 1f, 1f );}}

Class draggableobjectscene inherits the three interfaces: idraghandler, ipointerdownhandler, and ipointeruphandler, which can be acceptedOndrag (pointereventdata eventdata),Onpointerdown (pointereventdata eventdata),Onpointerup (pointereventdata eventdata)Three events

Ii. Event System

Namespace: unityengine. eventsystems

Idraghandler (mousedrag)

Interface to implement if you wish to receiveOndragCallbacks.

Ipointerdownhandler (mousedown)

Interface to implement if you wish to receiveOnpointerdownCallbacks.

Ipointeruphandler (mouseup)

Interface to implement if you wish to receiveOnpointerupCallbacks.

Iii. Drag Effect

Ugui exercise (4) draggable object