asked on

column chart data label, position and rotation, c#

Please note that this question is not x-axis label, rather it is about data label on the column of the chart.

The following code does not rotate the data labels on the columns ( see line 59).

Question: How can I change the code below to do the following:
Part 1: Rotate the data labels by 90 degrees, and
Part 2: To position the data label values inside (middle portion) of their respective columns.

Do I need to reduce font-size to be inside the column?

As it stands, the data labels are positioned at the tip of the columns.

protected void createMonthlyChartImagesSmall(string YYYY, int RegionID, string Region, int Metric_ID, int MedCtrID, string MedCenter, string chartImageName)
    {
        //  protected void createChart1()
        var filePathName = "~\\image\\" + chartImageName + "Small.png";
        if (!File.Exists(Server.MapPath(filePathName)))
        {
            // some dummy values...
            Session["Metric_ID"] = Metric_ID;
            Session["YYYY"] = YYYY;
            Session["MedCtr_ID"] = MedCtrID;

            SqlDataSource mySqlDataSource = new SqlDataSource();
            mySqlDataSource.ConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings["ROD_July18ConnectionString"].ConnectionString;
            mySqlDataSource.SelectCommand = "spMonthlyChart";
            mySqlDataSource.SelectCommandType = SqlDataSourceCommandType.StoredProcedure;
            mySqlDataSource.SelectParameters.Add(new SessionParameter("Metric_ID", DbType.Int32, "Metric_ID"));
            mySqlDataSource.SelectParameters.Add(new SessionParameter("YYYY", DbType.String, "YYYY"));
            mySqlDataSource.SelectParameters.Add(new SessionParameter("MedCtr_ID", DbType.Int32, "MedCtr_ID"));

            Chart chart = new Chart();

            Series series = new Series("Default");
            series.ChartType = SeriesChartType.Column;
            chart.Series.Add(series);

            Series series2 = new Series("Default2");
            series2.ChartType = SeriesChartType.Line;
            series2.Color = System.Drawing.Color.Purple;// change color to put
            series2.BorderWidth = 1; // this is actually the line width...
            series2.BorderDashStyle = ChartDashStyle.Dot;
            //series2.IsValueShownAsLabel = true;

            chart.Series.Add(series2);

            ChartArea chartArea = new ChartArea();
            Axis yAxis = new Axis(chartArea, AxisName.Y);
            Axis xAxis = new Axis(chartArea, AxisName.X);

            series.XValueMember = "ColName"; // X
            series.YValueMembers = "ColValue"; // Y1
            series2.XValueMember = "ColName"; // X
            series2.YValueMembers = "Target"; // Y2
            chart.DataSource = mySqlDataSource;
            chart.DataBind();

            series2.IsValueShownAsLabel = false;
            series2.Points[0].IsValueShownAsLabel = true;

            chartArea.BackColor = Color.Transparent;// chart.ChartAreas.col
            chart.BackColor = Color.Transparent;
            chart.Series["Default"].Color = System.Drawing.Color.FromArgb(50, 140, 172, 0);
            chart.Series["Default"].Points[0].Color = System.Drawing.Color.FromArgb(50, 224, 0, 0);
            chart.Series["Default"].Points[chart.Series["Default"].Points.Count - 1].Color = System.Drawing.Color.FromArgb(30, 225, 128, 0);
            series.IsValueShownAsLabel = true; // 3 show value

            

            series.LabelForeColor = System.Drawing.Color.Black;
            series.LabelAngle = 90;
            //chart.ChartAreas[0].AxisX.LabelStyle.Angle = 90;
            chartArea.AxisX.MajorGrid.Enabled = false; // 1 don't show grid
            chartArea.AxisY.MajorGrid.Enabled = false;// 1 don't show grid
            chartArea.AxisY.LabelStyle.Enabled = false; // 2 remove y labels
            // 
            chartArea.AxisX.LabelStyle.Font = new Font("Arial", 8);
            chartArea.AxisX.LabelStyle.Angle = 90;
           // chartArea.AxisX.PositionToValue = midButtonsLabel;
//            protected void SummaryChart_Customize(object sender, EventArgs e)
//{
//    //hide label value if zero
//    foreach (System.Web.UI.DataVisualization.Charting.Series series in SummaryChart.Series)
//    {
//        foreach (System.Web.UI.DataVisualization.Charting.DataPoint point in series.Points)
//        {
//            if (point.YValues.Length > 0 && (double)point.YValues.GetValue(0) == 0)
//            {
//                point.IsValueShownAsLabel = false;
//            }
//        }
//    }
//}
            chartArea.AxisX.LabelStyle.ForeColor = System.Drawing.Color.White;
            chartArea.AxisX.LabelAutoFitStyle = 0;//??????? 
            //chart.BorderSkin.SkinStyle = BorderSkinStyle.FrameThin1;// add thin fram to border???????????
            chartArea.AxisY.MajorTickMark.Enabled = false; //5.remove tick marks and add border
            chartArea.BorderDashStyle = ChartDashStyle.Solid; //6. add border
            chartArea.BorderWidth = 1;
            chartArea.BorderColor = System.Drawing.Color.Black; //6. add border

            //chartArea.AxisX.IsLabelAutoFit = true;
            // chartArea.AxisX.LabelAutoFitStyle = LabelAutoFitStyles.LabelsAngleStep30;
            chartArea.AxisX.LabelStyle.Enabled = true;
            chartArea.AxisX.LabelStyle.Angle = -90; // 4 rotate x labels
            chartArea.AxisX.Interval = 1;// xhow all labels

            if (Metric_ID == 115 || Metric_ID == 113)
            {
                chart.Series["Default"].Color = System.Drawing.Color.FromArgb(255, 224, 0, 0);//light red;
                chart.Series["Default"].BackGradientStyle = GradientStyle.DiagonalLeft;
                chart.Series["Default"].BackSecondaryColor = System.Drawing.Color.FromArgb(255, 147, 0, 0);//dark red
            }
            else
            {
                chart.Series["Default"].Color = System.Drawing.Color.FromArgb(255, 152, 200, 0);//light green;
                chart.Series["Default"].BackGradientStyle = GradientStyle.DiagonalLeft;
                chart.Series["Default"].BackSecondaryColor = System.Drawing.Color.FromArgb(255, 129, 132, 0);//dark green
            }
            chart.Series["Default"].Points[0].Color = System.Drawing.Color.FromArgb(255, 255, 150, 0);//light orange ;//FromArgb(255, 224, 0, 0);//light Red;
            chart.Series["Default"].Points[0].BackGradientStyle = GradientStyle.DiagonalLeft;
            chart.Series["Default"].Points[0].BackSecondaryColor = System.Drawing.Color.FromArgb(255, 255, 105, 0);//Dark orange;//FromArgb(255, 147, 0, 0);//DarkRed;
            chart.Series["Default"].Points[chart.Series["Default"].Points.Count - 1].Color = System.Drawing.Color.FromArgb(255, 190, 124,207);//light purple;
            chart.Series["Default"].Points[chart.Series["Default"].Points.Count - 1].BackGradientStyle = GradientStyle.DiagonalLeft;
            chart.Series["Default"].Points[chart.Series["Default"].Points.Count - 1].BackSecondaryColor = System.Drawing.Color.FromArgb(255, 153,66,123);//dark purple
            //  series.LabelStyle.Font = new Font("Palatino Linotype", 12);

     //       chartArea.BackGradientStyle = GradientStyle.DiagonalLeft;
            chartArea.BackColor = System.Drawing.Color.White;// SlateGray;
     //       chartArea.BackSecondaryColor = System.Drawing.Color.White;
            // chartArea.Position.X = 0;
            //  chartArea.Position.Y = 0;

            series.Font = new Font("Arial", 8f);
            // chartArea.AxisX.Interval = 1;
  //          chart.Titles.Add(string.Format("{0}{1}{2} ", MedCenter, ", Metric " + Metric_ID, " - " + YYYY));
 //           chart.Titles[0].Alignment = ContentAlignment.TopLeft;
 //           chart.Titles[0].Font = new Font("Tahoma", 20f);
  //          chart.Titles[0].ForeColor = System.Drawing.Color.White;
            //chart.Titles[0].Font=Bold;

            chart.Width = new Unit(214, UnitType.Pixel);
            chart.Height = new Unit(158, UnitType.Pixel);
            chart.ChartAreas.Add(chartArea);
            string filename = "C:\\Users\\Mike\\Documents\\_smc\\__CS37\\MasterPageTestJul25\\image\\" + chartImageName + "Small.png";
            chart.SaveImage(filename, ChartImageFormat.Png);

        }
    }

Open in new window

Robert Schutt

Could it be that this is not possible? I looked into CustomProperties and TextAnnotations but couldn't find a solution.

Here is a solution using the PostPaint event; after creating the chart object (line 20) add this:

chart.PostPaint += new EventHandler<ChartPaintEventArgs>(chart_PostPaint);

Open in new window

Then add this event handler:

        void chart_PostPaint(object sender, ChartPaintEventArgs e) {

            Font fnt = new Font("Arial", 8);
            StringFormat sf = new StringFormat(StringFormatFlags.DirectionVertical);
            sf.Alignment = StringAlignment.Center;
            sf.LineAlignment = StringAlignment.Center;

            if (e.ChartElement.GetType().Name.Equals("Series")) {
                Series s = (Series)e.ChartElement;
                if (s.Name == "Default") {
                    for (int p = 0; p < s.Points.Count; p++) {
                        PointF p1 = new PointF(
                            (float)e.ChartGraphics.GetPositionFromAxis(s.ChartArea, AxisName.X, (e.Chart.ChartAreas[s.ChartArea].AxisX.Maximum - e.Chart.ChartAreas[s.ChartArea].AxisX.Minimum - 1) * (p + 1) / (s.Points.Count)),
                            (float)e.ChartGraphics.GetPositionFromAxis(s.ChartArea, AxisName.Y, s.Points[p].YValues[0] / 2)
                        );
                        PointF p1a = e.ChartGraphics.GetAbsolutePoint(p1);
                        e.ChartGraphics.Graphics.DrawString(s.Points[p].YValues[0].ToString(), fnt, Brushes.Black, p1a, sf);
                    }
                }
            }
        }

Open in new window

Mike Eghtebas

ASKER

Robert,

You are amazing. You make it all possible.

The data points show up rotated (I suppose by 90 degrees) in the middle of the columns. I tried to locate the angle value and change it to -90 (for a better readability) but I didn't see any angle entry.

Question: How can I rotate the values (now reads top-to-bottom) to read Bottpm-to-top?

Thank you,

Mike

Robert Schutt

Hmm good one. The rotation in this case is done by StringFormatFlags.DirectionVertical, but I don't see an obvious way to make it go from bottom to top. I did find some examples to draw a string rotated the other way with some more customization but the result was unreadable so I'm trying another option, will need some time though.

ASKER CERTIFIED SOLUTION

Robert Schutt

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