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How to snap a point to a coordinate grid (ArcObjects .NET 10.4 SDK)

How to snap a point to a coordinate grid


Snapping a point to a coordinate grid

The following code example creates a point, associates it with the spatial reference of a feature class, positions it in the center of the domain of that spatial reference, then snaps its coordinates to the spatial reference's coordinate grid:
[C#]
private void SnapToSpatialReference(IFeatureClass featureClass)
{
    if (featureClass == null)
    {
        return ;
    }
    IGeoDataset geoDataset=featureClass as IGeoDataset;
    ISpatialReference spatialReference=geoDataset.SpatialReference;
    IPoint point=new PointClass();

    // The IPoint interface inherits from the IGeometry interface.
    point.SpatialReference=spatialReference;

    // Assign to the point the mathematical (i.e., full double precision resolution) center of 
    // the x,y domain of this spatial reference.
    double xMin;
    double yMin;
    double xMax;
    double yMax;
    spatialReference.GetDomain(out xMin, out xMax, out yMin, out yMax);

    point.X=(xMin + xMax) * 0.5;
    point.Y=(yMin + yMax) * 0.5;

    // Snap the double precision center of the domain to a location representable in the domain. 
    // Specifically, a multiple of the resolution and offset from the xMin, yMin of the domain.
    System.Windows.Forms.MessageBox.Show("Before snapping: " + point.X + ", " +
        point.Y);
    point.SnapToSpatialReference();
    System.Windows.Forms.MessageBox.Show("After snapping: " + point.X + ", " +
        point.Y);
}
[VB.NET]
Private Sub SnapToSpatialReference(ByVal featureClass As IFeatureClass)
    If featureClass Is Nothing Then
        Exit Sub
    End If
    Dim geoDataset As IGeoDataset=CType(featureClass, IGeoDataset)
    Dim spatialReference As ISpatialReference=geoDataset.SpatialReference
    Dim point As IPoint=New PointClass()
    
    ' The IPoint interface inherits from the IGeometry interface.
    point.SpatialReference=spatialReference
    
    ' Assign to the point the mathematical (i.e., full double precision resolution) center of
    ' the x,y domain of this spatial reference.
    Dim xMin As Double, yMin As Double, xMax As Double, yMax As Double
    spatialReference.GetDomain(xMin, xMax, yMin, yMax)
    point.X=(xMin + xMax) * 0.5
    point.Y=(yMin + yMax) * 0.5
    
    ' Snap the double precision center of the domain to a location representable in the domain.
    ' Specifically, a multiple of the resolution and offset from the xMin, yMin of the domain.
    System.Windows.Forms.MessageBox.Show("Before snapping: " & point.X & ", " & point.Y)
    point.SnapToSpatialReference()
    System.Windows.Forms.MessageBox.Show("After snapping: " & point.X & ", " & point.Y)
End Sub


See Also:

Understanding coordinate management in ArcGIS




To use the code in this topic, reference the following assemblies in your Visual Studio project. In the code files, you will need using (C#) or Imports (VB .NET) directives for the corresponding namespaces (given in parenthesis below if different from the assembly name):
Development licensing Deployment licensing
ArcGIS for Desktop Basic ArcGIS for Desktop Basic
ArcGIS for Desktop Standard ArcGIS for Desktop Standard
ArcGIS for Desktop Advanced ArcGIS for Desktop Advanced
Engine Developer Kit Engine