ASP.NET怎么操作DataTable

有机会在博客园的博问频道上看到一个问题,《ASP.NET怎么操作DataTable》:

 

如上图,左边的这个表是程序构建出来的,不是数据库表,怎么通过操作DataTable手段得到右边的四个表?

 

Insus.NET尝试做了一下,算是练习DataTable的功力了。效果如下:

 

根据最初数据,Insus.NET在.aspx内放置了一个Gridview,用来显示最开始的数据。

View Code
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false">
                    <Columns>
                        <asp:TemplateField>
                            <HeaderTemplate>
                                Name
                            </HeaderTemplate>
                            <ItemTemplate>
                                <%Eval("Name"%>
                            </ItemTemplate>
                        </asp:TemplateField>
                        <asp:TemplateField>
                            <HeaderTemplate>
                                Quantity
                            </HeaderTemplate>
                            <ItemTemplate>
                                <%Eval("Quantity"%>
                            </ItemTemplate>
                        </asp:TemplateField>
                    </Columns>
                </asp:GridView>

 

创建一个DataTable,并填充数据:

View Code
 DataTable GetData()
    {
        DataTable table = new DataTable();
        table.Columns.Add("Name"typeof(string));
        table.Columns.Add("Quantity"typeof(int));
        table.Rows.Add("a"1);
        table.Rows.Add("a"2);
        table.Rows.Add("b"2);
        table.Rows.Add("b"2);
        table.Rows.Add("c"1);
        table.Rows.Add("c"2);
        table.Rows.Add("c"3);
        table.Rows.Add("c"4);
        return table;
    }

 

然后为刚才创建的Gridview绑定这个DataTable:

View Code
 protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            Data_Binding();
        }
    }

    private void Data_Binding()
    {
        this.GridView1.DataSource = GetData();
        this.GridView1.DataBind();
    }

 

为了得到报表1,它有三个字段,名称(Name),数量(Amount)和行数(Rowcount),Insus.NET还参考源数据,它还有一个数量(Quantity)字段。因此,Insus.NET写了一个类别Item,为以下导出报表作准备:

Item
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

/// <summary>
/// Summary description for Item
/// </summary>
namespace Insus.NET
{
    public class Item
    {
        private string _Name;
        private int _Quantity;
        private int _Amount;
        private int _RowCount;

        public string Name
        {
            get { return _Name; }
            set { _Name = value; }
        }
        public int Quantity
        {
            get { return _Quantity; }
            set { _Quantity = value; }
        }
        public int Amount
        {
            get { return _Amount; }
            set { _Amount = value; }
        }
        public int RowCount
        {
            get { return _RowCount; }
            set { _RowCount = value; }
        }

        public Item()
        {
            //
            
// TODO: Add constructor logic here
            
//
        }       

        public Item(string name, int quantity)
        {
            this._Name = name;
            this._Quantity = quantity;
        }

        public Item(string name, int amount,int rowCount)
        {
            this._Name = name;
            this._Amount = amount;
            this._RowCount = rowCount;
        }
    }
}

 

OK,现在我们写一个报表,在.aspx放在一个按钮,以及一个GridView,来显示报表,注意一个字段的绑定。

View Code
 <asp:Button ID="ButtonReport1" runat="server" Text="报表1" OnClick="ButtonReport1_Click" />
                <asp:GridView ID="GridView2" runat="server" AutoGenerateColumns="false">
                    <Columns>
                        <asp:TemplateField>
                            <HeaderTemplate>
                                Name
                            </HeaderTemplate>
                            <ItemTemplate>
                                <%Eval("Name"%>
                            </ItemTemplate>
                        </asp:TemplateField>
                        <asp:TemplateField>
                            <HeaderTemplate>
                                Amount
                            </HeaderTemplate>
                            <ItemTemplate>
                                <%Eval("Amount"%>
                            </ItemTemplate>
                        </asp:TemplateField>
                        <asp:TemplateField>
                            <HeaderTemplate>
                                RowCount
                            </HeaderTemplate>
                            <ItemTemplate>
                                <%Eval("RowCount"%>
                            </ItemTemplate>
                        </asp:TemplateField>
                    </Columns>
                </asp:GridView>

 

在.cs 写click事件:

View Code
 protected void ButtonReport1_Click(object sender, EventArgs e)
    {
        SortedList<string, Item> _sl = new SortedList<string, Item>();

        DataTable otable = GetData();
        foreach (DataRow dr in otable.Rows)
        {
            if (_sl.ContainsKey(dr["Name"].ToString()))
            {
                _sl[dr["Name"].ToString()].Amount += Convert.ToInt32(dr["Quantity"]);
                _sl[dr["Name"].ToString()].RowCount += 1;
            }
            else
            {
                Item i = new Item(dr["Name"].ToString(), Convert.ToInt32(dr["Quantity"]), 1);
                _sl.Add(dr["Name"].ToString(), i);
            }
        }

        this.GridView2.DataSource = _sl.Values;
        this.GridView2.DataBind();
    }


第一份报表,大功告成,只要DataTable数源数据有变化,报表也会随之变化。

接下来,完成第二个报表,在Insus.NET使用Repeater包含Repeater来实现。因此,前台Html代码如下,其中第一个Repeate内放置了一个HiddenField,来存储名称(Name)字段,当作子Repeater的参考传入。

View Code
<asp:Button ID="ButtonReport2" runat="server" Text="报表2" OnClick="ButtonReport2_Click" />
                <asp:Repeater ID="Repeater1" runat="server" OnItemDataBound="Repeater1_ItemDataBound">
                    <ItemTemplate>
                        <asp:HiddenField ID="HiddenField1" runat="server" Value='<%# Container.DataItem %>' />
                        <asp:Repeater ID="Repeater2" runat="server">
                            <HeaderTemplate>
                                <table border="1" cellspacing="0" cellpadding="5" style="margin: 10px; border-collapse: collapse;">
                                    <tr>
                                        <td>Name</td>
                                        <td>Quantity</td>
                                    </tr>
                            </HeaderTemplate>
                            <ItemTemplate>
                                <tr>
                                    <td><%Eval("Name"%></td>
                                    <td><%Eval("Quantity"%></td>
                                </tr>
                            </ItemTemplate>
                            <FooterTemplate>
                                </table>
                            </FooterTemplate>
                        </asp:Repeater>
                    </ItemTemplate>
                </asp:Repeater>

 

首先,我们需要从DataTable,获取名称(Name)唯一的记录存储起来,作为第一个Repeate控件的数据集数据源。

View Code
  protected void ButtonReport2_Click(object sender, EventArgs e)
    {
        this.Repeater1.DataSource = Names();
        this.Repeater1.DataBind();
    }

    List<string> Names()
    {
        List<string> t = new List<string>();
        DataTable otable = GetData();
        foreach (DataRow dr in otable.Rows)
        {
            if (!t.Contains(dr["Name"].ToString()))
                t.Add(dr["Name"].ToString());
        }
        return t;
    }

 

我们还要写第二个Repeater控件的数据源:

View Code
 List<Item> GetDataByName(string name)
    {
        List<Item> o = new List<Item>();
        DataTable otable = GetData();
        foreach (DataRow dr in otable.Rows)
        {
            if (name == dr["Name"].ToString())
            {
                Item i = new Item(dr["Name"].ToString(), Convert.ToInt32(dr["Quantity"]));
                o.Add(i);
            }
        }
        return o;
    }


为第二个Repeater控件绑定数据源,在绑写之前,得先找到这个控件,因此,你需要在第一个Repeater控件写OnItemDataBound="Repeater1_ItemDataBound"事件:

View Code
  protected void Repeater1_ItemDataBound(object sender, RepeaterItemEventArgs e)
    {
        if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
        {
            if (e.Item.FindControl("HiddenField1") != null && e.Item.FindControl("Repeater2") != null)
            {
                var hiddenField = e.Item.FindControl("HiddenField1"as HiddenField;
                var repeater = e.Item.FindControl("Repeater2"as Repeater;
                repeater.DataSource = GetDataByName(hiddenField.Value);
                repeater.DataBind();
            }
        }
    }

 

 

posted @ 2012-11-06 23:35  Insus.NET  阅读(2403)  评论(0编辑  收藏