实现NBear中的DataSource控件-技术开发专区

实现NBear中的DataSource控件

作者：teddyma 编辑：振宇 2007-06-06 15:33

Default.aspx

<%@ Page Language="C#" %>
<%@ Register TagPrefix="nb" Namespace="NBear.Web.Data" Assembly="NBear.Web.Data" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>NBear DataSource Test</title>
</head>
<body>
<form id="aspnetForm" runat="server">
<nb:NBearDataSource ID="TestDS" runat="server" ConnectionStringName="test access db"
TypeName="Entities.SimpleData" FilterExpression="{SimpleID} > 0" DefaultOrderByExpression="{SimpleID} DESC, {SimpleName}" />
<asp:GridView ID="TestGrid" runat="server" DataSourceID="TestDS" AllowSorting="true" AllowPaging="true"
PageSize="3" AutoGenerateEditButton="true" AutoGenerateDeleteButton="true" />
<br />
<asp:DetailsView ID="TestDetail" runat="server" DataSourceID="TestDS" DefaultMode="Insert"
AutoGenerateInsertButton="true" AutoGenerateRows="false">
<Fields><asp:BoundField DataField="SimpleName" HeaderText="Name" /></Fields>
</asp:DetailsView>
</form>
</body>
</html>

Default.aspx没有Code Behind代码，纯粹是用asp.net 2.0的控件和NBearDataSource来CRUD。页面Default.aspx的运行效果就是，GridView可以RUD，DetailsView中可以C。

第二个页面StrongTypeQuerySample.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="StrongTypeQuerySample.aspx.cs" Inherits="StrongTypeQuerySample" %>
<%@ Register TagPrefix="nb" Namespace="NBear.Web.Data" Assembly="NBear.Web.Data" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>NBear DataSource Test - Strong Type Query Sample</title>
</head>
<body>
<form id="form1" runat="server">
Name to Query: <asp:TextBox ID="txtName" runat="server"></asp:TextBox> (* as wild char) &nbsp;&nbsp;
Order By: <asp:DropDownList ID="listOrderByProperty" runat="server">
<asp:ListItem Selected="True" Text="SimpleId" Value="SimpleId"></asp:ListItem>
<asp:ListItem Text="SimpleName" Value="SimpleName"></asp:ListItem>
</asp:DropDownList>
<asp:DropDownList ID="listOrderByDesc" runat="server">
<asp:ListItem Selected="True" Text="ASC" Value="ASC"></asp:ListItem>
<asp:ListItem Text="DESC" Value="DESC"></asp:ListItem>
</asp:DropDownList>
&nbsp;<asp:Button ID="btnFind" runat="server" Text="Find" OnClick="btnFind_Click" /><br />
<br />
<nb:NBearDataSource ID="TestDS" runat="server" ConnectionStringName="test access db"
TypeName="Entities.SimpleData" />
<asp:GridView ID="TestGrid" runat="server" DataSourceID="TestDS" />
</form>
<hr />
<a href="Default.aspx">Back to Default</a>
</body>
</html>

该页面包含了一个简单的GridView和NBearDataSource和一组用于可视化查询的textbox和dropdownlist控件。

StrongTypeQuerySample.aspx.cs

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class StrongTypeQuerySample : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void btnFind_Click(object sender, EventArgs e)
{
string name = txtName.Text.Replace("*", "%");
if (!string.IsNullOrEmpty(name))
{
TestDS.Filter(Entities.SimpleData._.SimpleName.Like(name));
}
if (listOrderByProperty.SelectedValue == "SimpleId")
{
if (listOrderByDesc.SelectedIndex == 0)
{
TestDS.OrderBy(Entities.SimpleData._.SimpleId.Asc);
}
else
{
TestDS.OrderBy(Entities.SimpleData._.SimpleId.Desc);
}
}
else if (listOrderByProperty.SelectedValue == "SimpleName")
{
if (listOrderByDesc.SelectedIndex == 0)
{
TestDS.OrderBy(Entities.SimpleData._.SimpleName.Asc);
}
else
{
TestDS.OrderBy(Entities.SimpleData._.SimpleName.Desc);
}
}
}
}

在btnFind按钮的Click事件中，我们根据用户输入的查询条件和排序条件，使用NBearDataSource的Filter(WhereClip)和OrderBy(OrderByClip)方法进行动态查询。

注意，这两个方法个接收一个参数WhereClip/OrderByClip，它是nbear支持的强类型查询表达式参数。如示例中所示，我们可以方便的使用NBear支持的强类型查询语法指定查询条件和排序条件，如这里的line 24和line30。

第1页：Web.config 第2页：Default.aspx 第3页：NBearDataSource 的属性第4页：CRUD示例

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