ArcGIS Engine – Dragging Features Using ArcObjects and AxMapControl

arcgis-10.0arcgis-enginearcobjectsfeatures

I'm trying to implement moving a point feature in a custom C# ArcGIS Engine application on an AxMapControl. I've already created a custom tool to do some other things. And I can track when the user is doing a drag-type operation (i.e. click and hold while moving the mouse).

What I'd like to be able to do is give some visual feedback of the drag operation, but I'm not sure how to do that.

I can handle the feature selection, identifying the drag, and getting the new position, etc. Just need help specifically with the drag feedback. Ideally I would like to update the cursor to have the same symbology as the feature, but that's not an absolute requirement.

Best Answer

The trick to feedback is setting ISymbol.ROP to esriROPNotXOrPen and drawing the geometry twice, the first draw displays it, the second draw erases it. Be sure if you're using a multilayer symbol to set the ROP for each layer.

public class MyTool : ESRI.ArcGIS.Desktop.AddIns.Tool
{

    private ISymbol m_Symbol;
    private IPoint m_lastPoint;
    private bool m_Dragging = false;
    public MyTool()
    {
        m_Symbol = new SimpleMarkerSymbolClass();
        ((ISimpleMarkerSymbol)m_Symbol).Size = 20.0;
        m_Symbol.ROP2 = esriRasterOpCode.esriROPNotXOrPen; 
    }

    protected override void OnUpdate()
    {

    }
    protected override void OnMouseDown(Tool.MouseEventArgs arg)
    {
        m_Dragging = !m_Dragging;
        if (!m_Dragging)
            Draw(arg.X, arg.Y);
    }

    protected override void OnMouseMove(Tool.MouseEventArgs arg)
    {
        if(m_Dragging)
            Draw(arg.X, arg.Y);
    }

    private void Draw(int X, int Y)
    {
        var av = ArcMap.Document.FocusMap as IActiveView;
        var pnt = av.ScreenDisplay.DisplayTransformation.ToMapPoint(X, Y);
        av.ScreenDisplay.StartDrawing(av.ScreenDisplay.hDC, 0);
        av.ScreenDisplay.SetSymbol(m_Symbol);
        if(m_lastPoint != null)
            av.ScreenDisplay.DrawPoint(m_lastPoint);
        if (m_Dragging)
        {
            av.ScreenDisplay.DrawPoint(pnt);
            m_lastPoint = pnt;
        }
        else
            m_lastPoint = null;
        av.ScreenDisplay.FinishDrawing();
    }

    protected override bool OnDeactivate()
    {
        // todo
        return base.OnDeactivate();
    }
}

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ArcGIS Progress – Showing Progress in ArcGIS Engine Application

The code below works for me. If you load a new map, you'll need to re-wire your events. Maybe try start animating when IDisplayEvents.Start fires (and IViewRefresh.Drawing is true). Then stop animating when IActiveViewEvents.AfterDraw fires with drawPhase == esriViewDrawPhase.esriViewForeground.

private IDisplayEvents_Event m_dispevt;
private IActiveViewEvents_Event m_avEvt;
private int m_lastTick;
private void WireEvents(IMap map)
{
    Debug.Print("wiring");
    m_dispevt = ((IActiveView)map).ScreenDisplay as IDisplayEvents_Event;
    m_dispevt.DisplayStarted += new IDisplayEvents_DisplayStartedEventHandler(MainForm_DisplayStarted);
    m_dispevt.DisplayFinished += new IDisplayEvents_DisplayFinishedEventHandler(MainForm_DisplayFinished);
    m_dispevt.DisplayInvalidated += new IDisplayEvents_DisplayInvalidatedEventHandler(MainForm_DisplayInvalidated);
    m_dispevt.DisplayScrolled += new IDisplayEvents_DisplayScrolledEventHandler(MainForm_DisplayScrolled);
    m_avEvt = (IActiveViewEvents_Event)map;
    m_avEvt.AfterDraw += new IActiveViewEvents_AfterDrawEventHandler(m_avEvt_AfterDraw);
    m_avEvt.AfterItemDraw += new IActiveViewEvents_AfterItemDrawEventHandler(m_avEvt_AfterItemDraw);
}

void m_avEvt_AfterItemDraw(short Index, IDisplay Display, esriDrawPhase phase)
{
    Debug.Print("afteritemdraw {0} {1}", Index, phase);
}

void m_avEvt_AfterDraw(IDisplay Display, esriViewDrawPhase phase)
{
    if(phase == esriViewDrawPhase.esriViewForeground)
        Debug.Print("foreground finished afterdraw {0} {1} msecs", phase, Environment.TickCount - m_lastTick);
    if (phase == esriViewDrawPhase.esriViewBackground)
        m_lastTick = Environment.TickCount;
}

void MainForm_DisplayScrolled(IDisplay Display, int deltaX, int deltaY)
{
    Debug.Print("scrolled");
}

void MainForm_DisplayInvalidated(IDisplay Display, ESRI.ArcGIS.Geometry.IEnvelope rect, bool erase, short cacheID)
{
    Debug.Print("invalidated");
}

void MainForm_DisplayFinished(IDisplay Display)
{
    Debug.Print("finished");
}

void MainForm_DisplayStarted(IDisplay Display)
{
    Debug.Print("started {0}", ((IViewRefresh)axMapControl1.Map).Drawing);
}

ArcObjects – Replicating ArcMap’s Point Sketch Geometry Editing with Feature Templates

I haven't tested this much, but it seems to work ...

public class TestButton : ESRI.ArcGIS.Desktop.AddIns.Button
{
    public TestButton()
    {
    }

    protected override void OnClick()
    {
        try
        {
            var fLayer = StartEditing();
            if (fLayer != null)
            {
                ShowTemplate(fLayer);
                // id discovered using Categories.exe ...
                ShowDockWin("esriEditor.CreateFeatureDockWin");
            }        
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
    }

    private static void ShowDockWin(string id)
    {
        var dockWin = GetDockWindow(id);
        if (dockWin != null)
        {
            if (!dockWin.IsVisible())
                dockWin.Show(true);
        }
    }

    private static IFeatureLayer StartEditing()
    {
        IEditor editor = ArcMap.Application.FindExtensionByName("ESRI Object Editor") as IEditor;
        IFeatureLayer fLayer = null;
        if (editor.EditState == esriEditState.esriStateNotEditing)
        {
            fLayer = ArcMap.Document.FocusMap.get_Layer(0) as IFeatureLayer;
            if (fLayer == null)
            {
                MessageBox.Show("first layer is not a featurelayer");
                return null;
            }
            editor.StartEditing(((IDataset)fLayer).Workspace);
        }
        else
            MessageBox.Show("you are already editing");
        return fLayer;
    }

    private static void ShowTemplate(IFeatureLayer fLayer)
    {
        var ed3 = ArcMap.Application.FindExtensionByName("ESRI Object Editor") as IEditor3;
        var template = FindTemplate(ed3, fLayer);
        if (template == null)
        {
            IEditTemplateFactory factory = new EditTemplateFactoryClass();
            template = factory.Create(fLayer.Name, fLayer);
            ed3.AddTemplates(ToArray(template));
        }
        if(ed3.CurrentTemplate != template)
            ed3.CurrentTemplate = template;
    }

    private static IArray ToArray(params object[] args)
    {
        IArray array = new ArrayClass();
        foreach (object o in args)
            array.Add(o);
        return array;
    }

    private static IEditTemplate FindTemplate(IEditor3 ed3, ILayer layer)
    {
        for (int i = 0; i < ed3.TemplateCount; i++)
        {
            if (ed3.get_Template(i).Layer == layer)
            {
                ed3.CurrentTemplate = ed3.get_Template(i);
                return ed3.get_Template(i);
            }
        }
        return null;
    }

    private static IDockableWindow GetDockWindow(string id)
    {
        UID uid = new UIDClass();
        try
        {
            uid.Value = id;
        }
        catch
        {
            MessageBox.Show("unable to create dockable window for " + id);
        }
        var dwm = ArcMap.Application as IDockableWindowManager;
        var dockWin = dwm.GetDockableWindow(uid);
        return dockWin;
    }

    protected override void OnUpdate()
    {
    }
}

Best Answer

Related Solutions

ArcGIS Progress – Showing Progress in ArcGIS Engine Application

ArcObjects – Replicating ArcMap’s Point Sketch Geometry Editing with Feature Templates

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