DbConnectionStringBuilder.Remove(String) 方法

定义

命名空间:

System.Data.Common

程序集:

System.Data.Common.dll

Source:

DbConnectionStringBuilder.cs

从 DbConnectionStringBuilder 实例中移除具有指定的键的项。

public:
 virtual bool Remove(System::String ^ keyword);

public virtual bool Remove (string keyword);

abstract member Remove : string -> bool
override this.Remove : string -> bool

Public Overridable Function Remove (keyword As String) As Boolean

参数

keyword

String

要从此 DbConnectionStringBuilder 中的连接字符串移除的键/值对中的键。

返回

Boolean

如果该键存在于连接字符串中并已被移除，则为 true；如果该键不存在，则为 false。

例外

ArgumentNullException

keyword 为 Null（在 Visual Basic 中为 Nothing）

NotSupportedException

DbConnectionStringBuilder 是只读，或 DbConnectionStringBuilder 具有固定的大小。

示例

static void Main()
{
    DbConnectionStringBuilder builder = new
        DbConnectionStringBuilder();
    builder.ConnectionString =
        @"Provider=Microsoft.Jet.OLEDB.4.0;Data
            Source=C:\Demo.mdb;" +
        "Jet OLEDB:System Database=system.mdw;";

    // Try to remove an existing item.
    TryRemove(builder, "Provider");

    // Try to remove a nonexistent item.
    TryRemove(builder, "User ID");

    // Try to remove an existing item,
    // demonstrating that the search isn't
    // case sensitive.
    TryRemove(builder, "DATA SOURCE");
    Console.ReadLine();
}

static void TryRemove(DbConnectionStringBuilder builder, string itemToRemove)
{
    if (builder.Remove(itemToRemove))
    {
        Console.WriteLine(@"Removed '{0}'", itemToRemove);
    }
    else
    {
        Console.WriteLine(@"Unable to remove '{0}'", itemToRemove);
    }
    Console.WriteLine(builder.ConnectionString);
}

Sub Main()
    Dim builder As New DbConnectionStringBuilder
    builder.ConnectionString = _
        "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Demo.mdb;" & _
        "Jet OLEDB:System Database=system.mdw;"

    ' Try to remove an existing item.
    TryRemove(builder, "Provider")

    ' Try to remove a nonexistent item.
    TryRemove(builder, "User ID")

    ' Try to remove an existing item, 
    ' demonstrating that the search isn't 
    ' case sensitive.
    TryRemove(builder, "DATA SOURCE")
    Console.ReadLine()
End Sub

Sub TryRemove(ByVal builder As DbConnectionStringBuilder, _
    ByVal itemToRemove As String)

    If builder.Remove(itemToRemove) Then
        Console.WriteLine("Removed '{0}'", itemToRemove)
    Else
        Console.WriteLine("Unable to remove '{0}'", itemToRemove)
    End If
    Console.WriteLine(builder.ConnectionString)
End Sub

此示例显示以下输出：

Removed 'Provider'
data source=C:\Demo.mdb;jet oledb:system database=system.mdw
Unable to remove 'User ID'
data source=C:\Demo.mdb;jet oledb:system database=system.mdw
Removed 'DATA SOURCE'
jet oledb:system database=system.mdw

注解

Remove由于 方法返回一个值，该值指示其成功，因此在尝试从实例中删除键/值对之前，不需要查找密钥DbConnectionStringBuilder。

另请参阅

• ADO.NET 中的连接字符串
• ADO.NET 概述