I have the following code to create a simple bar graph at run-time and then exports it as an image to the users computer.
[HttpGet]
public HttpResponseMessage Get([FromBody]ScoreByLocation sblx)
{
sbl.ImageWidth = 400;
sbl.ImageHeight = 300;
HttpResponseMessage msg = null;
try
{
WebChartControl sideBySideBarChart = new WebChartControl();
sideBySideBarChart.Width = sbl.ImageWidth;
sideBySideBarChart.Height = sbl.ImageHeight;
DevExpress.XtraCharts.Series series1 = new DevExpress.XtraCharts.Series("Side-by-Side Bar Series 1", ViewType.Bar);
sideBySideBarChart.Series.Add(series1);
DataTable dt = new DataTable();
DataColumn dc;
dc = new DataColumn();
dc.ColumnName = "Name";
dt.Columns.Add(dc);
dc = new DataColumn();
dc.ColumnName = "Age";
dt.Columns.Add(dc);
(other data creation here..)
sideBySideBarChart.DataSource = dt;
series1.ArgumentScaleType = ScaleType.Numerical;
series1.ArgumentDataMember = "Argument";
series1.ValueScaleType = ScaleType.Numerical;
series1.ValueDataMembers.AddRange(new string[] { "Value" });
sideBySideBarChart.DataBind();
//save to memory stream and then to byte array
byte[] b = null;
using (MemoryStream ms = new MemoryStream())
{
((IChartContainer)sideBySideBarChart).Chart.ExportToImage(ms, System.Drawing.Imaging.ImageFormat.Png);
b = ms.ToArray();
}
msg = Request.CreateResponse(HttpStatusCode.OK);
msg.Content = new ByteArrayContent(b);
msg.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("image/png");
msg.Content.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("attachment");
msg.Content.Headers.ContentDisposition.FileName = "report.png";
}
catch (Exception ex)
{
msg = Request.CreateErrorResponse(HttpStatusCode.InternalServerError, ex.Message.ToString());
}
return msg;
}
}
}
For some reason when I run this code, the graph that is returned is blank. I am able to view the image and it has all the properties I want (i.e height, width etc.) but for some reason there are no axis or bars or other data for that matter. If someone could point out what I have done wrong it would be appreciated.
Thanks
