c# - AjaxControlToolkit PieChart graphic does not render if only one data value is added -

i enter data dynamically code behind:

piechart1.piechartvalues.add(new ajaxcontroltoolkit.piechartvalue { category = "1", data = count1 }); 

it supposed reflect number of ratings 1-10 use of switch (i didn't show entire switch because cumbersome). in case, if 1 person gives rating of 1, count1 = 1, , want pie chart reflect that, instead control remains blank , has 1 way @ corner, legend still there.

is bug or missing something?

update: here switch goes through ratings 1 - 10 , adds amount of particular rating chart:

for (int = 1; <= 10; i++)                 {                     switch (i)                     {                         case 1:                             if (count1 > 0)                             {                                 piechart1.piechartvalues.add(new ajaxcontroltoolkit.piechartvalue                                 {                                     category = "1",                                     data = count1                                 });                             }                             break;                         case 2:                             if (count2 > 0)                             {                                 piechart1.piechartvalues.add(new ajaxcontroltoolkit.piechartvalue                                 {                                     category = "2",                                     data = count2                                 });                             }                             break;                         case 3:                             if (count3 > 0)                             {                                 piechart1.piechartvalues.add(new ajaxcontroltoolkit.piechartvalue                                 {                                     category = "3",                                     data = count3                                 });                             }                             break;                         case 4:                             if (count4 > 0)                             {                                 piechart1.piechartvalues.add(new ajaxcontroltoolkit.piechartvalue                                 {                                     category = "4",                                     data = count4                                 });                             }                             break;                         case 5:                             if (count5 > 0)                             {                                 piechart1.piechartvalues.add(new ajaxcontroltoolkit.piechartvalue                                 {                                     category = "5",                                     data = count5                                 });                             }                             break;                         case 6:                             if (count6 > 0)                             {                                 piechart1.piechartvalues.add(new ajaxcontroltoolkit.piechartvalue                                 {                                     category = "6",                                     data = count6                                 });                             }                             break;                         case 7:                             if (count7 > 0)                             {                                 piechart1.piechartvalues.add(new ajaxcontroltoolkit.piechartvalue                                 {                                     category = "7",                                     data = count7                                 });                             }                             break;                         case 8:                             if (count8 > 0)                             {                                 piechart1.piechartvalues.add(new ajaxcontroltoolkit.piechartvalue                                 {                                     category = "8",                                     data = count8                                 });                             }                             break;                         case 9:                             if (count9 > 0)                             {                                 piechart1.piechartvalues.add(new ajaxcontroltoolkit.piechartvalue                                 {                                     category = "9",                                     data = count9                                 });                             }                             break;                         case 10:                             if (count10 > 0)                             {                                 piechart1.piechartvalues.add(new ajaxcontroltoolkit.piechartvalue                                 {                                     category = "10",                                     data = count10                                 });                             }                             break;                     } 

you doing right, piechart not produce valid svg markup when there single value in series, see nothing in result.