c# - How to group data on the YAxis of a .NET chart? -

i have .net chart looks this:

here code used generate it:

protected void page_load(object sender, eventargs e) {   // set chart properties   ganttchart.width = 800;   ganttchart.height = 500;    // create chart area   var area = new chartarea();         ganttchart.chartareas.add(area);   ganttchart.chartareas[0].axisy.labelstyle.angle = 30; // unknown reason y-axis x-axis   ganttchart.chartareas[0].axisy.labelstyle.format = "hh:mm dd/mmm";;     // set data   var dt = new datatable();   dt.columns.add("name", typeof(string));   dt.columns.add("seriesid", typeof(double));   dt.columns.add("y", typeof(datetime));   dt.columns.add("y2", typeof(datetime));   dt.rows.add("a", 1, new datetime(2015, 10, 22, 8, 0, 0), new datetime(2015, 10, 22, 9, 0, 0));     dt.rows.add("a", 1, new datetime(2015, 10, 22, 10, 0, 0), new datetime(2015, 10, 22, 12, 0, 0));     dt.rows.add("a", 1, new datetime(2015, 10, 22, 18, 0, 0), new datetime(2015, 10, 22, 20, 0, 0));   dt.rows.add("b", 2, new datetime(2015, 10, 22, 8, 30, 0), new datetime(2015, 10, 22, 9, 13, 0));     dt.rows.add("b", 2, new datetime(2015, 10, 22, 17, 0, 0), new datetime(2015, 10, 22, 18, 43, 0));   dt.rows.add("c", 3, new datetime(2015, 10, 22, 13, 0, 0), new datetime(2015, 10, 22, 14, 0, 0));     dt.rows.add("c", 3, new datetime(2015, 10, 22, 14, 22, 0), new datetime(2015, 10, 22, 14, 32, 0));    var series = new series();   series.name = "series1";   series.charttype = seriescharttype.rangebar;   series.yvaluetype = chartvaluetype.datetime;    // add series chart   ganttchart.series.add(series);   ganttchart.series[series.name].points.databind(dt.select(), "seriesid", "y,y2", "label=name");   ganttchart.series[series.name].label = "y = name";  } 

what want achieve name field of datatable label on y-axis, along left hand side of chart see a, b & c instead of 0,1,2,3,4.

if change databind method use name instead of series id affect i'm after loose y-axis grouping. ends looking this:

what need happy medium grouping first picture , labels second. how can achieve this?

the solution problem not rely on databinding , instead create each point manually , add series myself. way had more control on properties of each point.

i made method called mapdatarowtodatapoint looked this:

private datapoint mapdatarowtodatapoint(datarow row) {   try{     var point = new datapoint();      point.xvalue = double.parse(row["seriesid"].tostring());     point.yvalues = new double[]{         convert.todatetime(row["y1"].tostring()).tooadate(),          convert.todatetime(row["y2"].tostring()).tooadate()     };     point.axislabel = row["seriesname"].tostring();      point.color = colortranslator.fromhtml("#" + row["colour"].tostring());     point.borderwidth = 1;     point.bordercolor = color.black;     point.tooltip = row["tooltip"].tostring()                     + ((!string.isnullorempty(row["tooltip"].tostring()))?"\n":"")                     + "start date time: #valy{"+tooltipdatetimeformat+"}\n"                      +"end date time:   #valy2{"+tooltipdatetimeformat+"}";     point.isvalueshownaslabel = false;     point.postbackvalue = row["postbackvalue"].tostring();      return point;   }   catch   {     //log error     return null;   } } 

here can see map row of datatable datapoint object , can control each property of data point in great detail.

now, instead of databinding, loop through each row of data source , call above method, add point chart's series:

// each row of datasource, create data point , add chart   foreach(datarow row in data.rows)   {     var point = mapdatarowtodatapoint(row);     if(point != null)       ganttchart.series[0].points.add(point);   } 

this method proved more painless relying on data binding. hope helps!