ArcGIS Pro 2.6 API Reference Guide
M Property (MapPoint)
Example 

ArcGIS.Core.Geometry Namespace > MapPoint Class : M Property
Gets the measure value.
Syntax
public double M {get;}
Public ReadOnly Property M As Double
Example
// Use a builder convenience method or use a builder constructor.

MapPoint point1 = null;

// Builder constructors need to run on the MCT.
ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
{
  using (MapPointBuilder mb = new MapPointBuilder(1.0, 2.0, 3.0))
  {
    bool bhasZ = mb.HasZ;          // hasZ = true
    bool bhasM = mb.HasM;          // hasM = false
    bool bhasID = mb.HasID;        // hasID = false

    // do something with the builder

    point1 = mb.ToGeometry();
  }
});

double x = point1.X;                  // x = 1.0
double y = point1.Y;                  // y = 2.0
double z = point1.Z;                  // z = 3.0
double m = point1.M;                  // m = Nan
int ID = point1.ID;                   // ID = 0
bool hasZ = point1.HasZ;              // hasZ = true
bool hasM = point1.HasM;              // hasM = false
bool hasID = point1.HasID;            // hasID = false
bool isEmpty = point1.IsEmpty;        // isEmpty = false

// Builder convenience methods don't need to run on the MCT.
MapPoint point2 = MapPointBuilder.CreateMapPoint(point1);
x = point2.X;                   // x = 1.0
y = point2.Y;                   // y = 2.0
z = point2.Z;                   // z = 3.0
m = point2.M;                   // m = Nan
hasZ = point2.HasZ;           // hasZ = true
hasM = point2.HasM;           // hasM = false
hasID = point2.HasID;         // hasID = false
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 7

See Also

Reference

MapPoint Class
MapPoint Members