Control添加Drop支持

*代码示例,为Control添加Drop支持

int ops = DND.DROP_COPY;
Transfer[] transfers = new Transfer[]{
　　　　LocalSelectionTransfer.getInstance(),
};

DropTarget target =new DropTarget(YourControl,ops); //定义DropTarget
target.setTransfer(transfers);
target.addDropListener(new DropTargetAdapter(){
	public void dragEnter(DropTargetEvent event) {
		if(event.operations==DND.DROP_COPY)
			event.detail =DND.DROP_COPY;
		else
			event.detail =DND.DROP_NONE;　//否决drop
	}

	public void drop(DropTargetEvent event) {
		if(LocalSelectionTransfer.getInstance().isSupportedType(event.currentDataType)){
			if(event.data instanceof IStructuredSelection){
				Object obj =((IStructuredSelection)event.data).getFirstElement();
				//TODO 实现代码
			}
　　　　}

      public void dropAccept(DropTargetEvent event) {
		if (event.operations == DND.DROP_COPY)
			event.detail = DND.DROP_COPY;
		else
			event.detail = DND.DROP_NONE;
	}

}