using DataView with asp.net Chart control

Question

How can i use this table below to plug a pie chat?

state	SumPostVoice	SumPostData	SumPreVoice	SumPreData
National	324	42	9	2

My DataView is

 

 

DataView PieDv = PieTable.DefaultView;

Chart2.Series[

 

"Default"].Points.DataBindXY(PieDv, "State", PieDv, "SumPostVoice");

Chart2.Series[

 

"Default"].Points.DataBindXY(PieDv, "State", PieDv, "SumPostData");

Chart2.Series[

 

"Default"].Points.DataBindXY(PieDv, "State", PieDv, "SumPreVoice");

Chart2.Series[

 

"Default"].Points.DataBindXY(PieDv, "State", PieDv, "SumPreData");

 

 

 

 

When i load my chart i just get one big round doughnut color and its just says national.
I taught it was going to divide it into 100%.

Thanks in Advance

Answer 1

Normally you would use the values in a single column

If you want to use the values in 1 row, you have to iterate through all the column values

Dim dtTest As New DataTable
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        dtTest.Columns.Add("State", GetType(String))
        dtTest.Columns.Add("Sum_Post_Voice", GetType(Integer))
        dtTest.Columns.Add("Sum_Post_Data", GetType(Integer))
        dtTest.Columns.Add("Sum_Pre_Voice", GetType(Integer))
        dtTest.Columns.Add("Sum_Pre_Data", GetType(Integer))
        DataGridView1.DataSource = dtTest.DefaultView
        dtTest.Rows.Add("National", 324, 42, 9, 2)

    End Sub

    Private Sub btnGraph_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGraph.Click
        
        Chart1.Series(0).ChartType = DataVisualization.Charting.SeriesChartType.Doughnut
        Chart1.Series(0).IsValueShownAsLabel = True
        For i As Integer = 1 To dtTest.Columns.Count - 1
            Chart1.Series(0).Points.AddY(dtTest.Rows(0).Item(i))
        Next


    End Sub

Answer 2

Thanks Jwavila,
                    But  i would also need the x axis which is the column name.
How can i get that?
Thx in Advance

Answer 3

I'm sorry, can you explain why you need two axis to draw a circle. Last time I checked a pie chart only had one real dimension.

For the purists who can't wait to chime in, yeah, I know any graph takes up space in two dimensions, but we're talking about the data to fuel the chart itself, yeah?

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Answer 4

Cole thanks for the trply.
Yeah you are right about needing only one axis.
Sorry what i want is to show the label text on the pie chat.
Right now i can see the pie chart divided  and all good but i want label text.

How can i get the columns in my data as above to show as a label.

If not can i hardcode it e.g like so
string[] xValues = { "SumPostVoice", "SumPostData", "SumPreVoice", "SumPreData" };

Hope you understand me now and thks in Advance

Answer 5

Hi

I think he means that he wants to have the column name in the description of the pie chart. just check into more details of the ms chart i never worked with ms charts but i have used devexpress charts and in that we had a wizard through which you could do it easily. I think u will be able to find it if u digg a little deeper.

Wish you luck

HG

Answer 6

Thanks hammer thats exactly what i want.

 Cole,hammer 
  i noticed i can use the 
 Chart2.Series["Default"].Label = "#VAL{#}";
 to add the label to display on the pie chart

But this is where i have the proble with the legend text
 Chart2.Series["Default"].LegendText = "#AXISLABEL";
when i use the above  the legend shows 324, 42, 9, 2

I need a text for the legend unless it looks funny.
How can i get the column names or even hardcode the values dynamically

My code below:

for (int i = 0; i <= PieTable.Columns.Count - 1; i++)
            {
              
                Chart2.Series["Default"].Points.AddY(PieTable.Rows[0].ItemArray[i]);
                Chart2.Series["Default"].LegendText = "#AXISLABEL";
                Chart2.Series["Default"].Label = "#VAL{#}";
               //How can i get the column names
         }


Sure i tried doing :

  foreach (DataColumn column in PieTable.Columns)
        {
            
                       Chart2.Series["Default"].LegendText = column.ToString();
        }  

But no cigar.
Thks

Answer 7

in your loop through the columns, you can get the column name from each. But since you are skipping the first column for the data, the first point is using the data from the second column. So you just have to offset the index by 1.

this also has some code to add a Title to your Chart, using the value in the first column, so the data in the "State" column shows up on the chart

Private Sub btnGraph_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGraph.Click
        Chart1.Series(0).Points.Clear()
        Chart1.Titles.Clear()

        Chart1.Series(0).ChartType = DataVisualization.Charting.SeriesChartType.Pie
        Chart1.Series(0).IsValueShownAsLabel = True
        Chart1.Titles.Add(dtTest.Rows(DataGridView1.SelectedRows(0).Index).Item(0).ToString)
        For i As Integer = 1 To dtTest.Columns.Count - 1
            Chart1.Series(0).Points.AddY(dtTest.Rows(DataGridView1.SelectedRows(0).Index).Item(i))
            Chart1.Series(0).Points(i - 1).LegendText = dtTest.Columns(i).ColumnName.ToString
        Next

End Sub

Answer 8

The legends take binding from supplied table's column name also, if you don't know.

Try something like below :

 

SomeChart.Series[0].Legend = PieTable.Columns[0].ColumnName;

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If you find solution from my answer, please mark it as answer.