Dear Support Team,

How we obtain the cartesian grid line annotation value exact based in mouse position  to plot vertical or horizontal grid line annotations using mouse click without insert the exact value manually?

Thanks in advance!

Best regards,

Henrique

Other image 

Hi Dimitar,

Thank you very much for your support!

The first issue is about the 'RadChartView.Annotations.Add(annotationToAdd)' method ,
when we add annotations using this method to create vertical and horizontal annotations with one mouse click the vertical line is created but the position is incorrect,  the behavior is strange.

The same does not ocurres when we using 'RadChartView.Annotations.AddRange(annotations.ToArray())'.

Please see the attached images and the code below:

 

  private void RadChartView1_MouseDown(object sender, MouseEventArgs e)

        {
            CreateHorizontalAnnotation(e);

            CreateVerticalAnnotation(e);

            //1 Works correctly
            //radChartView1.Annotations.AddRange(annotations.ToArray());
        }
  
  
  #region Create Cartesian Annotations Methods

        private void CreateHorizontalAnnotation(MouseEventArgs e)
        {
            var mousePos = e.Location.Y;
            var verticalAxis = radChartView1.Axes[1] as LinearAxis;
            var minDistance = double.MaxValue;
            var value = double.NaN;
            var step = (verticalAxis.ActualRange.Maximum - verticalAxis.ActualRange.Minimum) / verticalAxis.Model.LayoutSlot.Height;

            for (var i = verticalAxis.ActualRange.Minimum; i < verticalAxis.ActualRange.Maximum; i += step)
            {
                var loc1 = verticalAxis.GetLocationOfValue(i) + radChartView1.View.Margin.Top;

                var currentDistance = Math.Abs(loc1 - mousePos);

                if (currentDistance < minDistance)
                {
                    minDistance = currentDistance;
                }
                else
                {
                    value = i;
                    break;
                }

            }

            var annotation1 = new CartesianGridLineAnnotation
            {
                Axis = radChartView1.Axes[1] as CartesianAxis,
                Value = value,
                BorderColor = Color.Red,
                BorderDashStyle = DashStyle.Solid,
                BorderWidth = 1
            };

            //1 Works correctly
            //annotations.Add(annotation1);

            //2 It doesn't work.
            this.radChartView1.Annotations.Add(annotation1);
        }

        private void CreateVerticalAnnotation(MouseEventArgs e)
        {
            var mousePos = e.Location.X;

            var horizontalAxis = radChartView1.Axes[0] as DateTimeContinuousAxis;

            DateTime? value = null;

            var referenceDate = horizontalAxis.ActualRange.Minimum;

            var referencePosition = mousePos;

            do
            {
                var loc1 = horizontalAxis.GetLocationOfValue(referenceDate) + radChartView1.View.Margin.Right;

                if (loc1 > referencePosition)
                    break;

                value = referenceDate;

                referenceDate = referenceDate.AddSeconds(1);

            } while (referenceDate <= horizontalAxis.ActualRange.Maximum);


            if (!value.HasValue)
                return;

            var annotation = new CartesianGridLineAnnotation
            {
                Axis = radChartView1.Axes[0] as DateTimeContinuousAxis,
                Value = value,
                BorderColor = Color.Blue,
                BorderDashStyle = DashStyle.Solid,
                BorderWidth = 1
            };

            //1 Works correctly
            //annotations.Add(annotation);

            //2 It doesn't work.
            this.radChartView1.Annotations.Add(annotation);
        }

        #endregion

I would like to know if my method to create the vertical line in mouse click position when the data is of type DateTimeContinuousAxis is correct or exist some the advice to this solution,

Can I use the mouse move event to automatically show the cartesian grid line annotation and display the values between the ticks in a label? Exists a advice about this question,

Thanks in advanced,
Henrique

Hi Dimitar,

Thank you very much for your support!

Best regards,
Henrique

Hi Dimitar,

The methods works ok but when the zoom is aplicatted the position does not correctly. How we get the exact position when i have zoom applied?

Thanks in advance!

Best regards,
Henrique

Hi Henrique,

Thank you for writing.

Indeed, the current zoom factors are not taken into consideration. You need to change the GetVerticalAxisValueFromMouse and GetHorizontalAxisValueFromMouse methods this way: 
I hope this helps. Should you have further questions please do not hesitate to write back.

Regards,
Hristo
Progress Telerik

Hi Hristo

It worked!
Thank you very much for your support!

Best regards,

Henrique