/// <summary>
/// Start dragging.
/// 开始拖动。
/// </summary>
/// <param name="source">Source object. This is the object which initiated the dragging.</param>
/// <param name="icon">Icon to be used as the dragging sign.</param>
/// <param name="sourceData">Custom data. You can get it in the onDrop event data.</param>
/// <param name="touchPointID">Copy the touchId from InputEvent to here, if has one.</param>
public void StartDrag(GObject source, string icon, string icon2, object sourceData, int touchPointID = -1)
{
if (_agent.parent != null)
{
return;
}
loader_a.url = icon;
loader_b.url = icon2;
_sourceData = sourceData;
GRoot.inst.AddChild(_agent);
_agent.xy = GRoot.inst.GlobalToLocal(Stage.inst.GetTouchPosition(touchPointID));
_agent.StartDrag(touchPointID);
}