Hi Mohammadmk,

Add a Legend and show the names in Legend. This is the only option which you can display it in nice way.

Populate ASP.Net 4.0 Chart Control Pie Chart from SQL Server Database

Using the above article i have created example. Check this example. Now please take its reference and correct your code.

HTML

<asp:Chart ID="Chart1" runat="server">
    <Legends>
        <asp:Legend Docking="Right" LegendStyle="Table" />
    </Legends>
    <Series>
        <asp:Series Name="Series1" ChartArea="ChartArea1" ChartType="Column">
        </asp:Series>
    </Series>
    <ChartAreas>
        <asp:ChartArea Name="ChartArea1">
            <AxisX Title="Properties Owner">
            </AxisX>
            <AxisY Title="Total Properties">
            </AxisY>
        </asp:ChartArea>
    </ChartAreas>
</asp:Chart>

Namespaces

C#

using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Web.UI.DataVisualization.Charting;

VB.Net

Imports System.Data
Imports System.Data.SqlClient
Imports System.Web.UI.DataVisualization.Charting

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        string query = string.Format("select TOP 20 shipcity, count(orderid) from orders group by shipcity");
        DataTable dt = GetData(query);
        string[] x = new string[dt.Rows.Count];
        int[] y = new int[dt.Rows.Count];
        for (int i = 0; i < dt.Rows.Count; i++)
        {
            x[i] = dt.Rows[i][0].ToString();
            y[i] = Convert.ToInt32(dt.Rows[i][1]);
        }
        Chart1.Series[0].Points.DataBindXY(x, y);
        Chart1.Series[0].ChartType = SeriesChartType.Pie;
        Chart1.ChartAreas["ChartArea1"].Area3DStyle.Enable3D = false;
        Chart1.Legends[0].Enabled = true;
    }
}

private static DataTable GetData(string query)
{
    DataTable dt = new DataTable();
    SqlCommand cmd = new SqlCommand(query);
    String constr = ConfigurationManager.ConnectionStrings["ConString"].ConnectionString;
    SqlConnection con = new SqlConnection(constr);
    SqlDataAdapter sda = new SqlDataAdapter();
    cmd.CommandType = CommandType.Text;
    cmd.Connection = con;
    sda.SelectCommand = cmd;
    sda.Fill(dt);
    return dt;
}

VB.Net

Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
    If Not IsPostBack Then
        Dim query As String = String.Format("select TOP 20 shipcity, count(orderid) from orders group by shipcity")
        Dim dt As DataTable = GetData(query)
        Dim x As String() = New String(dt.Rows.Count - 1) {}
        Dim y As Integer() = New Integer(dt.Rows.Count - 1) {}
        For i As Integer = 0 To dt.Rows.Count - 1
            x(i) = dt.Rows(i)(0).ToString()
            y(i) = Convert.ToInt32(dt.Rows(i)(1))
        Next

        Chart1.Series(0).Points.DataBindXY(x, y)
        Chart1.Series(0).ChartType = SeriesChartType.Pie
        Chart1.ChartAreas("ChartArea1").Area3DStyle.Enable3D = False
        Chart1.Legends(0).Enabled = True
    End If
End Sub

Private Shared Function GetData(query As String) As DataTable
    Dim dt As New DataTable()
    Dim cmd As New SqlCommand(query)
    Dim constr As [String] = ConfigurationManager.ConnectionStrings("ConString").ConnectionString
    Dim con As New SqlConnection(constr)
    Dim sda As New SqlDataAdapter()
    cmd.CommandType = CommandType.Text
    cmd.Connection = con
    sda.SelectCommand = cmd
    sda.Fill(dt)
    Return dt
End Function

Screenshot