ArcObjects Library Reference (Carto)  

IMapServerLayout.FromPagePoints Method

Converts a page coordinate to a screen location.

[Visual Basic .NET]
Public Sub FromPagePoints ( _
    ByVal pageExtent As IEnvelope, _
    ByVal pageDisplay As IImageDisplay, _
    ByVal pagePoints As IPointCollection, _
    ByRef screenXValues As ILongArray, _
    ByRef screenYValues As ILongArray _
)
[C#]
public void FromPagePoints (
    IEnvelope pageExtent,
    IImageDisplay pageDisplay,
    IPointCollection pagePoints,
    ref ILongArray screenXValues,
    ref ILongArray screenYValues
);
[C++]
HRESULT FromPagePoints(
  IEnvelope* pageExtent,
  IImageDisplay* pageDisplay,
  IPointCollection* pagePoints,
  ILongArray** screenXValues,
  ILongArray** screenYValues
);
[C++]

Parameters

pageExtent [in]

  pageExtent is a parameter of type IEnvelope

pageDisplay [in]

  pageDisplay is a parameter of type IImageDisplay

pagePoints [in]

  pagePoints is a parameter of type IPointCollection

screenXValues [in, out]

  screenXValues is a parameter of type ILongArray

screenYValues [in, out]

  screenYValues is a parameter of type ILongArray

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Remarks

Use FromPagePoints to convert page unit coordinates on the layout to pixel coordinates on the screen.

[C#]

The following sample code shows how to convert the upper left corner of your page (page coordinates) to a screen location. It assumes that you already have a valid MapServerLayout and PageDescription object, and that you are not working with a server context. However, if you are developing an ArcGIS for Server application using a server context, you should not use New to create local ArcObjects, but you should always create objects within the server by calling CreateObject on IServerContext.

IMapServerLayout mapServerLayout;
IPageDescription pageDesc;

// Create image display
IImageDisplay imageDisp = new ImageDisplayClass();
imageDisp.Height = 550;
imageDisp.Width = 425;

// Get page coordinates (upper left corner)
IEnvelope pageExtent = pageDesc.Extent;
IPoint point = new PointClass();
point.X = pageExtent.XMin;
point.Y = pageExtent.YMax;

// Add point to point collection
IPointCollection pointCollection = new MultipointClass();
System.Object pMissing = System.Reflection.Missing.Value;
pointCollection.AddPoint(point, ref pMissing, ref pMissing);

// Convert page coordinates to screen location
ILongArray screenXValues = new LongArrayClass ();
ILongArray screenYValues = new LongArrayClass ();
mapServerLayout.FromPagePoints(pageExtent, imageDisp, pointCollection, ref screenXValues, ref screenYValues);

// Please note:
// 1. Origin of screen coordinate system is upper left corner
// 2. If aspect ratio of requested layout image is different from aspect ratio of
// input map layout, requested layout image will be adjusted to fit
// input map layout -> following screen locations are not necessarily 0:
MessageBox.Show(screenXValues.get_Element(0).ToString());
MessageBox.Show(screenYValues.get_Element(0).ToString());

See Also

IMapServerLayout Interface