OleDbConnectionStringBuilder 类

定义

public ref class OleDbConnectionStringBuilder sealed : System::Data::Common::DbConnectionStringBuilder

[System.ComponentModel.TypeConverter(typeof(System.Data.OleDb.OleDbConnectionStringBuilder+OleDbConnectionStringBuilderConverter))]
public sealed class OleDbConnectionStringBuilder : System.Data.Common.DbConnectionStringBuilder

[<System.ComponentModel.TypeConverter(typeof(System.Data.OleDb.OleDbConnectionStringBuilder+OleDbConnectionStringBuilderConverter))>]
type OleDbConnectionStringBuilder = class
    inherit DbConnectionStringBuilder

Public NotInheritable Class OleDbConnectionStringBuilder
Inherits DbConnectionStringBuilder

继承

Object

DbConnectionStringBuilder

OleDbConnectionStringBuilder

属性

TypeConverterAttribute

示例

以下控制台应用程序为多个 OLE DB 数据库生成连接字符串。 首先，该示例为 Microsoft Access 数据库创建连接字符串，然后为 IBM DB2 数据库创建连接字符串。 该示例还分析现有连接字符串，并演示了操作连接字符串内容的各种方法。

using System.Data.OleDb;

class Program
{
    static void Main(string[] args)
    {
        OleDbConnectionStringBuilder builder = new OleDbConnectionStringBuilder();
        builder.ConnectionString = @"Data Source=C:\Sample.mdb";

        // Call the Add method to explicitly add key/value
        // pairs to the internal collection.
        builder.Add("Provider", "Microsoft.Jet.Oledb.4.0");
        builder.Add("Jet OLEDB:Database Password", "MyPassword!");
        builder.Add("Jet OLEDB:System Database", @"C:\Workgroup.mdb");

        // Set up row-level locking.
        builder.Add("Jet OLEDB:Database Locking Mode", 1);

        Console.WriteLine(builder.ConnectionString);
        Console.WriteLine();

        // Clear current values and reset known keys to their
        // default values.
        builder.Clear();

        // Pass the OleDbConnectionStringBuilder an existing
        // connection string, and you can retrieve and
        // modify any of the elements.
        builder.ConnectionString =
            "Provider=DB2OLEDB;Network Transport Library=TCPIP;" +
            "Network Address=192.168.0.12;Initial Catalog=DbAdventures;" +
            "Package Collection=SamplePackage;Default Schema=SampleSchema;";

        Console.WriteLine("Network Address = " + builder["Network Address"].ToString());
        Console.WriteLine();

        // Modify existing items.
        builder["Package Collection"] = "NewPackage";
        builder["Default Schema"] = "NewSchema";

        // Call the Remove method to remove items from
        // the collection of key/value pairs.
        builder.Remove("User ID");

        // Note that calling Remove on a nonexistent item does not
        // throw an exception.
        builder.Remove("BadItem");
        Console.WriteLine(builder.ConnectionString);
        Console.WriteLine();

        // Setting the indexer adds the value, if
        // necessary.
        builder["User ID"] = "SampleUser";
        builder["Password"] = "SamplePassword";
        Console.WriteLine(builder.ConnectionString);

        Console.WriteLine("Press Enter to finish.");
        Console.ReadLine();
    }
}

Imports System.Data.OleDb
Imports System.Collections

Module Module1
  Sub Main()
    Dim builder As New OleDbConnectionStringBuilder()
    builder.ConnectionString = "Data Source=C:\Sample.mdb"

    ' Call the Add method to explicitly add key/value
    ' pairs to the internal collection.
    builder.Add("Provider", "Microsoft.Jet.Oledb.4.0")
    builder.Add("Jet OLEDB:Database Password", "MyPassword!")
    builder.Add("Jet OLEDB:System Database", "C:\Workgroup.mdb")

    ' Set up row-level locking.
    builder.Add("Jet OLEDB:Database Locking Mode", 1)

    Console.WriteLine(builder.ConnectionString)
    Console.WriteLine()

    ' Clear current values and reset known keys to their
    ' default values.
    builder.Clear()

    ' Pass the OleDbConnectionStringBuilder an existing
    ' connection string, and you can retrieve and
    ' modify any of the elements.
    builder.ConnectionString = "..."

    Console.WriteLine("Network Address = " & builder("Network Address").ToString())
    Console.WriteLine()

    ' Modify existing items.
    builder("Package Collection") = "NewPackage"
    builder("Default Schema") = "NewSchema"

    ' Call the Remove method to remove items from
    ' the collection of key/value pairs.
    builder.Remove("User ID")

    ' Note that calling Remove on a nonexistent item does not
    ' throw an exception.
    builder.Remove("BadItem")
    Console.WriteLine(builder.ConnectionString)
    Console.WriteLine()

    ' The Item property is the default for the class,
    ' and setting the Item property adds the value, if
    ' necessary.
    builder("User ID") = "SampleUser"
    builder("Password") = "SamplePassword"
    Console.WriteLine(builder.ConnectionString)

    Console.WriteLine("Press Enter to finish.")
    Console.ReadLine()
  End Sub
End Module

注解

通过连接字符串生成器，开发人员可以使用该类的属性和方法，以编程方式创建语法正确的连接字符串以及分析和重新生成现有的连接字符串。 连接字符串生成器提供与 OLE DB 连接允许的已知键/值对对应的强类型属性，开发人员可以为任何其他连接字符串值添加任意键/值对。 OleDbConnectionStringBuilder 类实现 ICustomTypeDescriptor 接口。 这意味着 类在设计时与 Visual Studio .NET 设计器一起使用。 当开发人员使用设计器在 Visual Studio .NET 中生成强类型数据集和强类型连接时，强类型连接字符串生成器类将显示与其类型关联的属性，并且还将具有可映射已知键的通用值的转换器。

需要在应用程序中创建连接字符串的开发人员可以使用 OleDbConnectionStringBuilder 类生成和修改连接字符串。 使用该类还可以轻松管理存储在应用程序配置文件中的连接字符串。 仅 OleDbConnectionStringBuilder 检查已知键/值对的有限集。 因此，此类可用于创建无效的连接字符串。 下表列出了 类中的 OleDbConnectionStringBuilder 已知键及其相应属性及其默认值。 除了这些特定值之外，开发人员还可以将任何键/值对添加到 实例中包含的集合：OleDbConnectionStringBuilder

属性 Item[] 处理插入恶意条目的尝试。 例如，以下代码在 C#) 中使用索引器 (默认 Item[] 属性正确转义嵌套键/值对：

Dim builder As _
    New System.Data.OleDb.OleDbConnectionStringBuilder
builder("Provider") = "Microsoft.Jet.OLEDB.4.0"
builder("Data Source") = "C:\Sample.mdb"
builder("User Id") = "Admin;NewValue=Bad"

System.Data.OleDb.OleDbConnectionStringBuilder builder =
    new System.Data.OleDb.OleDbConnectionStringBuilder();
builder["Provider"] = "Microsoft.Jet.OLEDB.4.0";
builder["Data Source"] = "C:\\Sample.mdb";
builder["User Id"] = "Admin;NewValue=Bad";

结果为以下连接字符串，该字符串以安全方式处理无效值：

Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Sample.mdb;User ID="Admin;NewValue=Bad"

另请参阅

• 连接字符串生成器
• ADO.NET 中的连接字符串