实验指导书(display)

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1、1Display1.1如何实现在ArcMap中放大缩小地图用户点击按钮后，可以在地图上进行点击或者拖放矩形框来放大缩小地图l要点因为考虑到用户可以单击放大缩小，也可以拖放矩形框来放大缩小，所以不可以直接使用IRubberBand接口，而是采用INewEnvelopeFeedback接口l程序说明主要通过InewEnvelopeFeedback.StartPoint和MoveTo方法来绘制矩形框，然后赋值给IActiveView.Extend属性，达到地图的放大缩小l代码Privatem_pFeedbackEnvAsINewEnvelopeFeedbackPrivatem_pPo

2、intAsIPointPrivatem_bIsMouseDownAsBooleanPrivatem_pActiveViewAsIActiveViewPrivateSubUIToolControl1_MouseDown(ByValbuttonAsLong,ByValshiftAsLong,ByValxAsLong,_ByValyAsLong)DimpMxDocumentAsIMxDocumentOnErrorGoToErrorHandler:'LeftButtonCheckIfbutton<>1ThenExitSubIfm_pActiveViewIsNothingThenSetp

3、MxDocument=ThisDocumentSetm_pActiveView=pMxDocument.ActivatedViewEndIf'得到起始点Setm_pPoint=m_pActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint(x,y)m_bIsMouseDown=TrueExitSubErrorHandler:MsgBoxErr.DescriptionEndSubPrivateSubUIToolControl1_MouseMove(ByValbuttonAsLong,ByValshiftAsLong,ByV

4、alxAsLong,_ByValyAsLong)OnErrorGoToErrorHandler:IfNotm_bIsMouseDownThenExitSubIfm_pFeedbackEnvIsNothingThenSetm_pFeedbackEnv=NewNewEnvelopeFeedbackSetm_pFeedbackEnv.Display=m_pActiveView.ScreenDisplaym_pFeedbackEnv.Startm_pPointEndIfSetm_pPoint=m_pActiveView.ScreenDisplay.DisplayTransformati

5、on.ToMapPoint(x,y)'DrawEnvelopem_pFeedbackEnv.MoveTom_pPointExitSubErrorHandler:MsgBoxErr.DescriptionEndSubPrivateSubUIToolControl1_MouseUp(ByValbuttonAsLong,ByValshiftAsLong,ByValxAsLong,_ByValyAsLong)DimpEnvAsIEnvelopeOnErrorGoToErrorHandler:'LeftButtonCheckIfbutton<>1ThenExitSubIf(m_pFeed

6、backEnvIsNothing)Then'UserOnlyClickMapwithleftbuttonSetpEnv=m_pActiveView.Extent'如果是缩小的话，将这里的两个0.5都改成1.5pEnv.Expand0.5,0.5,TrueElse'UserDrawaEnvelopeSetpEnv=m_pFeedbackEnv.StopEndIfm_pActiveView.Extent=pEnvm_bIsMouseDown=FalseSetm_pPoint=NothingSetm_pFeedbackEnv=Nothingm_pActiveView.RefreshE

7、xitSubErrorHandler:MsgBoxErr.DescriptionEndSub1.2如何实现在ArcMap中移动地图用户点击按钮后，可以拖动地图显示l要点采用IActiveView.ScreenDisplay.PanStart和PanStop方法使地图移动。l程序说明通过IActiveView.ScreenDisplay的PanStart和PanStop方法在ITool的MouseDown,MouseUp和MouseMove事件的响应实现移动效果，将移动结果得到IEnvelop