Question

My page has a chart that is set up to display data that is coming from a SqlDataSource.

There is a TreeView which contains a list of datapoints that I want to be able to add to the chart as different series. The user selects which item they wish to add by clicking a checkbox in the treeview for that node and then clicks an update button to refresh the chart.

Each node’s value is set to a column name in the table.

If there is only one point selected on the treeview the data comes across as a series on the chart with no problem when the update button is clicked.

If multiple items in the treeview are selected an ASP.NET error page appears when clicking the button stating that a column name ‘XXXX’ was not found where ‘XXXX’ is the node.Value of the highest item in the tree that was checked.

For example an error saying that “Column with name ‘X1’ was not found” would show up when using the following selection:

If just ‘X1’ is checked the data shows up on the chart.

public void UpdateChart(Object sender, EventArgs e)
    {

        if (TagTreeView.CheckedNodes.Count > 0)
        {
            foreach (TreeNode node in TagTreeView.CheckedNodes)
            {
                // Add a series to the chart
                Series series = new Series();
                series=Chart1.Series.Add("Series"+node.Value);
                series.ChartArea = "ChartArea1";
                series.ChartType = (SeriesChartType)Enum.Parse(typeof(SeriesChartType), charts[1], true);
                // create a datasource, add it to the page,
                SqlDataSource sqlDataSource = new SqlDataSource();
                sqlDataSource.ID = "SQLDataSource"+node.Value;
                sqlDataSource.ConnectionString = ConfigurationManager.ConnectionStrings["HistoricalDataConnectionString"].ConnectionString;
                if (node.Depth > 1)
                {
                    if (node.Parent.Text.Contains("AAA"))
                    {
                        MessageBox.Show(node.Value);
                        sqlDataSource.SelectCommand = "SELECT (Date + CONVERT(datetime,Time)) As TimeStamp, " + node.Value + " FROM AAA ORDER BY TimeStamp";
                    }

                    this.Page.Controls.Add(sqlDataSource);
                    Chart1.DataSourceID = "SQLDataSource"+node.Value;

                    Chart1.Series["Series" + node.Value].XValueMember = "TimeStamp";
                    Chart1.Series["Series" + node.Value].YValueMembers = node.Value;

                    Chart1.DataBind();
                }
            }
        }
    }

Is there a way to take each selected item in the TreeView and use the node.value to build a query to add an additional series to the chart? I have done a little bit of work to see if putting the SqlDatasource and Series objects into an array and looping through that but it doesn’t seem to be taking me anywhere.

Answer 1

To get this to work correctly all of the datapoints that will be added to the chart need to be included in the select statement for the sqlDataSource:

sqlDataSource.SelectCommand = "SELECT (Date + CONVERT(datetime,Time)) As TimeStamp, X1, X2, X3 FROM AAA ORDER BY TimeStamp";