DbConnectionStringBuilder.Item[String] 属性

public:
 virtual property System::Object ^ default[System::String ^] { System::Object ^ get(System::String ^ keyword); void set(System::String ^ keyword, System::Object ^ value); };

public virtual object this[string keyword] { get; set; }

[System.ComponentModel.Browsable(false)]
public virtual object this[string keyword] { get; set; }

member this.Item(string) : obj with get, set

[<System.ComponentModel.Browsable(false)>]
member this.Item(string) : obj with get, set

Default Public Overridable Property Item(keyword As String) As Object

参数

属性值

与指定键关联的值。 如果未找到指定的键，则尝试获取它会引发一个 ArgumentException，并尝试设置它使用指定的键创建一个新元素。

在 Visual Basic 中传递 null （Nothing） 键将引发 ArgumentNullException。 分配 null 值会删除键/值对。

属性

BrowsableAttribute

例外

示例

以下控制台应用程序使用 DbConnectionStringBuilder 属性创建一个新的 Item[]，并将键/值对添加到其连接字符串。

static void Main()
{
    DbConnectionStringBuilder builder = new
        DbConnectionStringBuilder();
    builder["Data Source"] = "(local)";

    // Note that Item is the indexer, so
    // you do not include it in the reference.
    builder["integrated security"] = true;
    builder["Initial Catalog"] = "AdventureWorks";

    // Overwrite the existing value for the Data Source key,
    // because it already exists within the collection.
    builder["Data Source"] = ".";

    Console.WriteLine(builder.ConnectionString);
    Console.WriteLine();
    Console.WriteLine("Press Enter to continue.");
    Console.ReadLine();
}

Module Module1

    Sub Main()
        Dim builder As New DbConnectionStringBuilder
        builder.Item("Data Source") = "(local)"

        ' Item is the default property, so 
        ' you need not include it in the reference.
        builder("integrated security") = True
        builder.Item("Initial Catalog") = "AdventureWorks"

        ' Overwrite the existing value for the data source value, 
        ' because it already exists within the collection.
        builder.Item("Data Source") = "."

        Console.WriteLine(builder.ConnectionString)
        Console.WriteLine()
        Console.WriteLine("Press Enter to continue.")
        Console.ReadLine()
    End Sub

注解

设置此属性时，如果字典中已存在指定的键，则会替换该值;否则，将创建一个新元素。

另请参阅

• ADO.NET 中的连接字符串
• ADO.NET 概述