ExpressionBuilderCollection Classe

Definizione

public ref class ExpressionBuilderCollection sealed : System::Configuration::ConfigurationElementCollection

[System.Configuration.ConfigurationCollection(typeof(System.Web.Configuration.ExpressionBuilder))]
public sealed class ExpressionBuilderCollection : System.Configuration.ConfigurationElementCollection

[<System.Configuration.ConfigurationCollection(typeof(System.Web.Configuration.ExpressionBuilder))>]
type ExpressionBuilderCollection = class
    inherit ConfigurationElementCollection

Public NotInheritable Class ExpressionBuilderCollection
Inherits ConfigurationElementCollection

Ereditarietà

Object

ConfigurationElement

ConfigurationElementCollection

ExpressionBuilderCollection

Attributi

ConfigurationCollectionAttribute

Esempio

In questa sezione vengono forniti due esempi di codice. La prima illustra come specificare in modo dichiarativo i valori per diverse proprietà della ExpressionBuilderCollection classe . Il secondo illustra come usare i membri della ExpressionBuilderCollection classe .

Nell'esempio di file di configurazione seguente viene illustrato come specificare in modo dichiarativo i valori per diverse proprietà della ExpressionBuilderCollection classe .

<system.web>
  <compilation>
    <expressionBuilders>
      <add
        expressionPrefix="Resources"
        type="System.Web.Compilation.ResourceExpressionBuilder"/>
      <add
        expressionPrefix="ConnectionStrings"
        type="System.Web.Compilation.
        ConnectionStringsExpressionBuilder"/>
      <add expressionPrefix="AppSettings"
        type="System.Web.Compilation.AppSettingsExpressionBuilder" />
    </expressionBuilders>
  </compilation>
</system.web>

Nell'esempio di codice seguente viene illustrato come usare i membri della ExpressionBuilderCollection classe .

#region Using directives

using System;
using System.Configuration;
using System.Web.Configuration;

#endregion

namespace Samples.Aspnet.SystemWebConfiguration
{
  class UsingExpressionBuildCollection
  {
    static void Main(string[] args)
    {
      try
      {
        // Set the path of the config file.
        string configPath = "";

        // Get the Web application configuration object.
        Configuration config =
          WebConfigurationManager.OpenWebConfiguration(configPath);

        // Get the section related object.
        CompilationSection configSection =
          (CompilationSection)config.GetSection("system.web/compilation");

        // Display title and info.
        Console.WriteLine("ASP.NET Configuration Info");
        Console.WriteLine();

        // Display Config details.
        Console.WriteLine("File Path: {0}",
          config.FilePath);
        Console.WriteLine("Section Path: {0}",
          configSection.SectionInformation.Name);

        // Create a new ExpressionBuilder reference.
        ExpressionBuilder myExpressionBuilder =
          new ExpressionBuilder("myCustomExpression", "MyCustomExpressionBuilder");
        // Add an ExpressionBuilder to the configuration.
        configSection.ExpressionBuilders.Add(myExpressionBuilder);

        // Add an ExpressionBuilder to the configuration.
        ExpressionBuilder myExpressionBuilder2 =
          new ExpressionBuilder("myCustomExpression2", "MyCustomExpressionBuilder2");
        configSection.ExpressionBuilders.Add(myExpressionBuilder2);

        // Display the ExpressionBuilder count.
        Console.WriteLine("ExpressionBuilder Count: {0}",
          configSection.ExpressionBuilders.Count);

        // Display the ExpressionBuildersCollection details.
        int i = 1;
        int j = 1;
        foreach (ExpressionBuilder expressionBuilder in configSection.ExpressionBuilders)
        {
          Console.WriteLine();
          Console.WriteLine("ExpressionBuilder {0} Details:", i);
          Console.WriteLine("Type: {0}", expressionBuilder.ElementInformation.Type);
          Console.WriteLine("Source: {0}", expressionBuilder.ElementInformation.Source);
          Console.WriteLine("LineNumber: {0}", expressionBuilder.ElementInformation.LineNumber);
          Console.WriteLine("Properties Count: {0}", expressionBuilder.ElementInformation.Properties.Count);
          j = 1;
          foreach (PropertyInformation propertyItem in expressionBuilder.ElementInformation.Properties)
          {
            Console.WriteLine("Property {0} Name: {1}", j, propertyItem.Name);
            Console.WriteLine("Property {0} Value: {1}", j, propertyItem.Value);
            ++j;
          }
          ++i;
        }

        // Remove an ExpressionBuilder.
        configSection.ExpressionBuilders.RemoveAt
          (configSection.ExpressionBuilders.Count-1);

        // Remove an ExpressionBuilder.
        configSection.ExpressionBuilders.Remove("myCustomExpression");

        // Update if not locked.
        if (!configSection.SectionInformation.IsLocked)
        {
          config.Save();
          Console.WriteLine("** Configuration updated.");
        }
        else
        {
          Console.WriteLine("** Could not update, section is locked.");
        }
      }

      catch (Exception e)
      {
        // Unknown error.
        Console.WriteLine(e.ToString());
      }

      // Display and wait.
      Console.ReadLine();
    }
  }
}

Imports System.Configuration
Imports System.Web.Configuration

Namespace Samples.Aspnet.SystemWebConfiguration
  Class UsingExpressionBuildCollection
    Public Shared Sub Main()
      Try
        ' Set the path of the config file.
        Dim configPath As String = ""

        ' Get the Web application configuration object.
        Dim config As System.Configuration.Configuration = _
         WebConfigurationManager.OpenWebConfiguration(configPath)

        ' Get the section related object.
        Dim configSection As System.Web.Configuration.CompilationSection = _
         CType(config.GetSection("system.web/compilation"), _
         System.Web.Configuration.CompilationSection)

        ' Display title and info.
        Console.WriteLine("ASP.NET Configuration Info")
        Console.WriteLine()

        ' Display Config details.
        Console.WriteLine("File Path: {0}", _
         config.FilePath)
        Console.WriteLine("Section Path: {0}", _
         configSection.SectionInformation.Name)

        ' Create a new ExpressionBuilder reference.
        Dim myExpressionBuilder As ExpressionBuilder = _
          New ExpressionBuilder("myCustomExpression", "MyCustomExpressionBuilder")
        ' Add an ExpressionBuilder to the configuration.
        configSection.ExpressionBuilders.Add(myExpressionBuilder)

        ' Add an ExpressionBuilder to the configuration.
        Dim myExpressionBuilder2 As ExpressionBuilder = _
         New ExpressionBuilder("myCustomExpression2", "MyCustomExpressionBuilder2")
        configSection.ExpressionBuilders.Add(myExpressionBuilder2)

        ' Display the ExpressionBuilder count.
        Console.WriteLine("ExpressionBuilder Count: {0}", _
          configSection.ExpressionBuilders.Count)

        ' Display the ExpressionBuildersCollection details.
        Dim i = 1
        Dim j = 1
        For Each expressionBuilder As ExpressionBuilder In configSection.ExpressionBuilders()
          Console.WriteLine()
          Console.WriteLine("ExpressionBuilder {0} Details:", i)
          Console.WriteLine("Type: {0}", expressionBuilder.ElementInformation.Type)
          Console.WriteLine("Source: {0}", expressionBuilder.ElementInformation.Source)
          Console.WriteLine("LineNumber: {0}", expressionBuilder.ElementInformation.LineNumber)
          Console.WriteLine("Properties Count: {0}", expressionBuilder.ElementInformation.Properties.Count)
          j = 1
          For Each propertyItem As PropertyInformation In expressionBuilder.ElementInformation.Properties
            Console.WriteLine("Property {0} Name: {1}", j, propertyItem.Name)
            Console.WriteLine("Property {0} Value: {1}", j, propertyItem.Value)
            j = j + 1
          Next
          i = i + 1
        Next

        ' Remove an ExpressionBuilder.
        configSection.ExpressionBuilders.RemoveAt _
         (configSection.ExpressionBuilders.Count - 1)

        ' Remove an ExpressionBuilder.
        configSection.ExpressionBuilders.Remove("myCustomExpression")

        ' Update if not locked.
        If Not configSection.SectionInformation.IsLocked Then
          config.Save()
          Console.WriteLine("** Configuration updated.")
        Else
          Console.WriteLine("** Could not update, section is locked.")
        End If

      Catch e As Exception
        ' Unknown error.
        Console.WriteLine(e.ToString())
      End Try

      ' Display and wait
      Console.ReadLine()
    End Sub
  End Class
End Namespace

Commenti

La ExpressionBuilderCollection classe non fa riferimento ad alcun elemento effettivo nel file di configurazione sottostante. Si tratta di un costrutto che consente di accedere facilmente alle informazioni di compilazione contenute.

Vedi anche

• ExpressionBuilder
• ConfigurationElement