如何在ASP.NET图表控件中显示值

Question

I'm using a dataset as my data source to create a chart in asp.net, iv managed to display a column chart. Im now stuck on how I can display the values of each column on the chart.

Can some one please advice on how I may do this?

Answer 1

I am assuming you are using ASP.NET chart controls which come as standard with .net 4, the very basic chart you can get is by below code

<asp:Chart ID="Chart1" runat="server">
    <Series>
        <asp:Series Name="Series1" ChartType="Pie" Palette="EarthTones" >
            <Points>               
                <asp:DataPoint AxisLabel="Celtics" YValues="17" />
                <asp:DataPoint AxisLabel="Lakers" YValues="15" />
                <asp:DataPoint AxisLabel="Bulls" YValues="6" />
                <asp:DataPoint AxisLabel="Spurs" YValues="4" />
                <asp:DataPoint AxisLabel="76ers" YValues="3" />
                <asp:DataPoint AxisLabel="Pistons" YValues="3" />
                <asp:DataPoint AxisLabel="Warriors" YValues="3" />
            </Points>
        </asp:Series>
     </Series>
     <ChartAreas>
        <asp:ChartArea Name="ChartArea1" Area3DStyle-Enable3D="true" />
     </ChartAreas>
</asp:Chart>

Now, if you want to access this programmatically, you might want to download the sample project given at http://weblogs.asp.net/scottgu/archive/2008/11/24/new-asp-net-charting-control-lt-asp-chart-runat-quot-server-quot-gt.aspx and go through the sample code.The project is quite extensive and describes in details about everything you need to know about charts. If you are stuck at a specific logic or piece of code, could you post that so we can advise further

Thanks.

Answer 2

Strictly speaking..

From code behind:(my series is called overall)

   series_overal_overall.Label = "#PERCENT{P0}"

This will show the values in percent

---

To show a little more consider this sample.

from this barred data, i'm creating a lot of graphs, to keep it simple, i"ll just show 2

(sorry, i'm using 3d pie charts but anything goes)

a) my aspx page..

            <asp:Chart ID="chartOverall" runat="server"  Height="200px" Width="1000 px">
            <BorderSkin SkinStyle="Emboss" />
                <Titles> 
                <asp:Title  Text="Laptop" TextStyle="Shadow"  Font="Trebuchet MS, 14pt, style=Bold"  IsDockedInsideChartArea="false" DockedToChartArea="laptop"  ></asp:Title>
                <asp:Title  Text="Desktop" TextStyle="Shadow"  Font="Trebuchet MS, 14pt, style=Bold"  IsDockedInsideChartArea="false" DockedToChartArea="desktop" ></asp:Title>
                </Titles>
                <Legends>
                </Legends>
                <ChartAreas>
                    <asp:ChartArea Name="laptop"  Area3DStyle-Enable3D="true" > <Position Y="15" Height="65" Width="22" X="1"></Position></asp:ChartArea>
                    <asp:ChartArea Name="desktop" Area3DStyle-Enable3D="true" > <Position Y="15" Height="65" Width="22" X="34"></Position></asp:ChartArea>
                </ChartAreas> 
            </asp:Chart>

I define 2 labels and tell to wich chartarea they should be 'docked'. I do just one legend as the rest will done from codebehind. Finally, define the chartareas themselves.

In codebehind, i'm calling my sub to create the carts and pass a reference to the Table as shown above so i can process that date i've calculated to that time.

Protected Sub createchart(ByRef t As Table)
    'create series
    Dim series_overal_laptop As New Series("Overalll")
    Dim series_overal_desktop As New Series("Overalld")

    'create arrays
    Dim yvalueslaptop(1) As Integer  
    Dim yvaluesdesktop(1) As Integer


    Dim Xvalues(2) As String
    Dim Xvaluesio(1) As String

    ' fill X values
    For i = 1 To 2  ' in/out label.
        Xvaluesio(i - 1) = t.Rows(2).Cells(i).Text
    Next

so far the preparation work is done. Now we're going to put the Y values in.

' fill y values
        For i = 1 To 5 Step 2
        'laptops IN
        YValuesINL(((i + 1) / 2) - 1) = t.Rows(3).Cells(i).Text
        'Desktops IN
        YValuesIND(((i + 1) / 2) - 1) = t.Rows(4).Cells(i).Text
    Next
    For i = 2 To 6 Step 2
        'laptops out
        YValuesOUTL(((i) / 2) - 1) = t.Rows(3).Cells(i).Text
        'desktop out
        YValuesOUTD(((i) / 2) - 1) = t.Rows(4).Cells(i).Text
    Next

I'm reading basically all the odd Columns for the IN and the even columns for the out values. the Last letter specifies wether it's a Laptop (L) or a Desktop (D) value. Then sum up these read values as they contain the figures i want to show as a percentage of in warranty/out warranty. (Please note that i'm only showing a portion of the page, the intermediate arrays are being used elsewhere)

   'overall laptops and desktops
    'reuse the values i've collected already

    yvalueslaptop(0) = YValuesINL.Sum
    yvalueslaptop(1) = YValuesOUTL.Sum
    yvaluesdesktop(0) = YValuesIND.Sum
    yvaluesdesktop(1) = YValuesOUTD.Sum

 'now name and place the series, specfiy appearance and point values
    '#First Section 

    series_overal_laptop.Name = "laptop"
    series_overal_laptop.ChartArea = "laptop"
    series_overal_laptop.ChartType = SeriesChartType.Pie
    series_overal_laptop.Label = "#PERCENT{P0}"
    series_overal_laptop.IsVisibleInLegend = False

    series_overal_desktop.Name = "desktop"
    series_overal_desktop.ChartArea = "desktop"
    series_overal_desktop.ChartType = SeriesChartType.Pie
    series_overal_desktop.Label = "#PERCENT{P0}"
    series_overal_desktop.IsVisibleInLegend = True
    series_overal_desktop.LegendText = "#AXISLABEL"
    '#End of First Section 

For one of the charts, i'm hinding the legend as it's twice the same, i'll put the legend in the middel of the two charts later.

   ' now bind the datapoints to the series
     series_overal_laptop.Points.DataBindXY(Xvaluesio, yvalueslaptop)
    series_overal_desktop.Points.DataBindXY(Xvaluesio, yvaluesdesktop)

  'finally add the series to the charts
    chartOverall.Series.Dispose()  ' just to be sure nothing is left behind
   chartoverall.series.add(series_overal_laptop)
    chartOverall.Series.Add(series_overal_desktop)

    chartOverall.Series("laptop").Palette = ChartColorPalette.Excel
    chartOverall.Series("desktop").Palette = ChartColorPalette.Excel

and here i add my legend.

    'only 1 legend per chart is fine as they all have the same colors

    Dim topviewlegend As New Legend("topviewlegend")
    chartOverall.Legends.Add(topviewlegend)
    chartOverall.Series("desktop").Legend = "topviewlegend"
    topviewlegend.IsDockedInsideChartArea = False
    topviewlegend.Docking = 0
    topviewlegend.Position.Auto = False
    topviewlegend.Position.X = 20
    topviewlegend.Position.Y = 13
    topviewlegend.Position.Width = 20
    topviewlegend.Position.Height = 10

you need to play a bit with the values to position it correctly on your chartarea of course

If you want to see the values instead of a percentage, change your label for instance to.

 series_overal_laptop.Label = "#VALY"

hope this helps

K

Answer 3

Chart1.Series[0].IsValueShownAsLabel = true;