MetaModel Class

Reference

Definition

Namespace:: System.Web.DynamicData

Assembly:: System.Web.DynamicData.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Represents one or multiple databases that are used by ASP.NET Dynamic Data.

public ref class MetaModel

public class MetaModel

type MetaModel = class

Public Class MetaModel

Inheritance: Object
MetaModel

Examples

The following example shows how to use MetaModel type to perform the following tasks in order to use automatic scaffolding in an ASP.NET Web site:

Get the data model for the default data context.
Get the data model for a specified data context.
Evaluate the routing path (determine the URL) for a specified table.

The example consists of a page and its code-behind file.

using System;
using System.Web.DynamicData;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel;

[MetadataType(typeof(ProductMetaData))]
public partial class Product
{
}

public class ProductMetaData
{
}

<%@ Page Language="C#" AutoEventWireup="true" 
CodeFile="PathModel.aspx.cs" 
Inherits="PathModel" %>

<!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>Path Model</title>
</head>
<body>
    <asp:DynamicDataManager ID="DynamicDataManager1" runat="server"
        AutoLoadForeignKeys="true" />
    
    <h3>GetActionPath</h3>
       
    <form id="form1" runat="server">
        <asp:GridView ID="GridDataSource1" runat="server"
        AutoGenerateColumns="false"
        DataSourceID="LinqDataSource1"
        AllowPaging="true">
        <Columns>
        <asp:TemplateField>
          <ItemTemplate>
            <asp:HyperLink ID="HyperLink1" runat="server" 
            NavigateUrl="<%#EvaluateActionPath()%>">ListDetails</asp:HyperLink>
          </ItemTemplate>
         </asp:TemplateField>
          <asp:DynamicField DataField="FirstName" />
          <asp:DynamicField DataField="LastName" />
        </Columns>
      </asp:GridView>

        <asp:LinqDataSource ID="LinqDataSource1" runat="server" 
        TableName="Customers"
        ContextTypeName="AdventureWorksLTDataContext" >
      </asp:LinqDataSource>
    </form>
</body>

</html>

<%@ Page Language="VB" AutoEventWireup="false" 
CodeFile="PathModel.aspx.vb" 
Inherits="PathModel" %>

<!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 id="Head1" runat="server">
    <title>Path Model</title>
</head>
<body>
    <asp:DynamicDataManager ID="DynamicDataManager1" runat="server"
        AutoLoadForeignKeys="true" />
    
    <h3>GetActionPath</h3>
       
    <form id="form1" runat="server">
        <asp:GridView ID="GridDataSource1" runat="server"
        AutoGenerateColumns="false"
        DataSourceID="LinqDataSource1"
        AllowPaging="true">
        <Columns>
        <asp:TemplateField>
          <ItemTemplate>
            <asp:HyperLink ID="HyperLink1" runat="server" 
            NavigateUrl="<%#EvaluateActionPath()%>">ListDetails</asp:HyperLink>
          </ItemTemplate>
         </asp:TemplateField>
          <asp:DynamicField DataField="FirstName" />
          <asp:DynamicField DataField="LastName" />
        </Columns>
      </asp:GridView>

        <asp:LinqDataSource ID="LinqDataSource1" runat="server" 
        TableName="Customers"
        ContextTypeName="AdventureWorksLTDataContext" >
      </asp:LinqDataSource>
    </form>
</body>

</html>

Imports System.Web.DynamicData
Imports System.ComponentModel.DataAnnotations
Imports System.ComponentModel

<MetadataType(GetType(ProductMetaData))> _
Partial Public Class Product

End Class


Public Class ProductMetaData
    
   

End Class

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Web.DynamicData;

public partial class PathModel : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        DynamicDataManager1.RegisterControl(GridDataSource1);
    }

    // Get the data model. 
    public MetaModel GetModel(bool defaultModel)
    {
        MetaModel model;

        if (defaultModel)
            model = MetaModel.Default;
        else
            model =
               MetaModel.GetModel(typeof(AdventureWorksLTDataContext));
        return model;
    }

    // Get the registered action path.
    public string EvaluateActionPath()
    {
        string tableName = LinqDataSource1.TableName;
        
        MetaModel model = GetModel(false);

        string actionPath =
            model.GetActionPath(tableName,
                System.Web.DynamicData.PageAction.List, GetDataItem());
        return actionPath;
    }
}

Imports System.Collections
Imports System.Configuration
Imports System.Data
Imports System.Linq
Imports System.Web
Imports System.Web.Security
Imports System.Web.UI
Imports System.Web.UI.HtmlControls
Imports System.Web.UI.WebControls
Imports System.Web.UI.WebControls.WebParts
Imports System.Xml.Linq
Imports System.Web.DynamicData

Partial Public Class PathModel
    Inherits System.Web.UI.Page
    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
        DynamicDataManager1.RegisterControl(GridDataSource1)
    End Sub

    ' Get the data model. 
    Public Function GetModel(ByVal defaultModel As Boolean) As MetaModel
        Dim model As MetaModel

        If defaultModel Then
            model = MetaModel.[Default]
        Else
            model = MetaModel.GetModel(GetType(AdventureWorksLTDataContext))
        End If
        Return model
    End Function

    ' Get the registered action path.
    Public Function EvaluateActionPath() As String
        Dim tableName As String = LinqDataSource1.TableName

        Dim model As MetaModel = GetModel(False)

        Dim actionPath As String = model.GetActionPath(tableName, System.Web.DynamicData.PageAction.List, GetDataItem())
        Return actionPath
    End Function
End Class

To compile the example, you need the following:

Visual Studio 2010 or Visual Web Developer 2010 Express.
A Dynamic Data Web site. For more information, see Walkthrough: Creating a New Dynamic Data Web Site Using Scaffolding.

See a run-time code example of this feature: Run.

Remarks

The MetaModel type lets you register one or multiple data contexts for a Dynamic Data Web application.

A data context is an object that represents a database connection. A data context has access to one data model which represents a database that is available through that connection. A data model is an object that represents a database's data entities as CLR types. Dynamic Data supports data models based on LINQ to SQL and on the ADO.NET Entity Framework.

In Visual Studio, you can generate data-model types by using the LINQ to SQL Classes template or the ADO.NET Entity Data Model template. These templates use the Object Relational Designer (O/R Designer) for the LINQ to SQL model, or the ADO.NET Entity Data Model Designer (Entity Designer) for the Entity Framework model.

Constructors

MetaModel()	Instantiates a new instance of the MetaModel class.
MetaModel(Boolean)	Instantiates a new instance of the MetaModel class.

Properties

Default	Gets the first instance of a data model that is created by the application.
DynamicDataFolderVirtualPath	Gets or sets the virtual path of the DynamicData folder in the Web site.
EntityTemplateFactory	Gets or sets the EntityTemplateFactory object that is associated with the model.
FieldTemplateFactory	Gets or sets a custom IFieldTemplateFactory interface.
FilterFactory	Gets or sets the FilterFactory object that is associated with the model.
Tables	Gets a collection of all the tables that are part of the data model.
VisibleTables	Gets a collection of the visible tables in the data model.

Methods

CreateTable(TableProvider)	Instantiates a MetaTable object.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetActionPath(String, String, Object)	Returns the action path that is associated with a specific table.
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetModel(Type)	Returns the data-model instance for the specified context.
GetTable(String, Type)	Returns the metadata that describes the specified table.
GetTable(String)	Returns the metadata that is associated with the specified table.
GetTable(Type)	Returns the metadata that describes the specified table.
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
RegisterContext(DataModelProvider, ContextConfiguration)	Registers a data-context instance by using the specified context configuration and by enabling a data-model provider.
RegisterContext(DataModelProvider)	Registers a data context instance by using a data-model provider.
RegisterContext(Func<Object>, ContextConfiguration)	Registers a data-context instance by using the specified context configuration and by enabling a custom constructor.
RegisterContext(Func<Object>)	Registers the data context that is specified by a context factory.
RegisterContext(Type, ContextConfiguration)	Registers a data-context instance by using the specified context configuration.
RegisterContext(Type)	Registers a data-context instance.
ResetRegistrationException()	Resets any previous context registration error that might have occurred.
ToString()	Returns a string that represents the current object. (Inherited from Object)
TryGetTable(String, MetaTable)	Attempts to get the metadata that is associated with the specified table.
TryGetTable(Type, MetaTable)	Attempts to get the metadata that is associated with the specified table.

Applies to

แชร์ผ่าน