Question

下面给出的代码没有显示任何错误，也没有输出。我想在我的网页上显示ajax图表。我想在x轴上显示学生的姓名，在y轴上显示学生的年龄请帮助我。 C＃代码：

protected void Page_Load(object sender, EventArgs e)
    {
        SqlConnection conn = new SqlConnection(@"connectionString");
        conn.Open();

        SqlCommand cmd = new SqlCommand("select Name, Age from DemoTable", conn);
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataTable dt = new DataTable();
        da.Fill(dt);
        string[] x = new string[dt.Rows.Count];
        decimal[] y = new decimal[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]);
        }
        BarChart1.Series.Add(new AjaxControlToolkit.BarChartSeries { Data = y });
        BarChart1.CategoriesAxis = string.Join(",", x);

        BarChart1.ChartWidth = (x.Length * 160).ToString();
        BarChart1.ChartHeight = (y.Length * 50).ToString();    
    }

来源：

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="chart1.aspx.cs" Inherits="chart1" %>
<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %>
<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    <cc1:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server">
    </cc1:ToolkitScriptManager>

<hr />
    <cc1:BarChart ID="BarChart1" ChartType="column"  runat="server" Visible = "false">
    </cc1:BarChart> 
</div>
</form>
</body>
</html>

表：

enter image description here

Answer 1

 protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            string query = "select Name from aTable";
            DataTable dt = GetData(query);
            ddlCountries.DataSource = dt;
            ddlCountries.DataTextField = "Name";
            ddlCountries.DataValueField = "Name";
            ddlCountries.DataBind();
            ddlCountries.Items.Insert(0, new ListItem("Select", ""));
        }
    }
    private DataTable GetData(string query, SqlParameter[] prms = null)
    {
        DataTable dt = new DataTable();
        string constr = ConfigurationManager.ConnectionStrings["demoConnectionString"].ConnectionString;
        using (SqlConnection con = new SqlConnection(constr))
        {
            using (SqlCommand cmd = new SqlCommand(query))
            {
                if (prms != null)
                    cmd.Parameters.AddRange(prms);
                using (SqlDataAdapter sda = new SqlDataAdapter())
                {
                    cmd.CommandType = CommandType.Text;
                    cmd.Connection = con;
                    sda.SelectCommand = cmd;
                    sda.Fill(dt);
                }
            }
            return dt;
        }
    }
    protected void ddlCountries_SelectedIndexChanged(object sender, EventArgs e)
    {
        string query = "select Name, Debit, Credit From aTable where Name=@Name";
        SqlParameter[] prms = new SqlParameter[1];
        prms[0] = new SqlParameter("@name", SqlDbType.NVarChar);
        prms[0].Value = ddlCountries.SelectedItem.Value.ToString();
        DataTable dt = GetData(query, prms);

        string[] x = new string[dt.Rows.Count];
        decimal[] z = new decimal[dt.Rows.Count];
        decimal[] y = new decimal[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]);
            z[i] = Convert.ToInt32(dt.Rows[i][2]);
        }
        BarChart1.Series.Add(new AjaxControlToolkit.BarChartSeries { Data = y });
        BarChart1.Series.Add(new AjaxControlToolkit.BarChartSeries { Data = z });
        BarChart1.CategoriesAxis = string.Join(",", x);
        BarChart1.ChartTitle = string.Format("{0} -RunTimeReportChart", ddlCountries.SelectedItem.Value);
        if (x.Length > 20)
        {
            BarChart1.ChartWidth = (x.Length * 100).ToString();
        }
        BarChart1.Visible = ddlCountries.SelectedItem.Value != "";

    }

如何绑定和显示ajax图表控件

1 个答案: