SqlConnectionStringBuilder.ContainsKey(String) 方法

定義

命名空間:

System.Data.SqlClient

組件:

System.Data.SqlClient.dll

套件:

System.Data.SqlClient v4.9.0

來源:

System.Data.SqlClient.notsupported.cs

判斷 SqlConnectionStringBuilder 是否包含特定索引鍵。

public:
 override bool ContainsKey(System::String ^ keyword);

public override bool ContainsKey (string keyword);

override this.ContainsKey : string -> bool

Public Overrides Function ContainsKey (keyword As String) As Boolean

參數

keyword

String

要在 SqlConnectionStringBuilder 中尋找的索引鍵。

傳回

Boolean

如果 SqlConnectionStringBuilder 包含具有指定索引鍵的項目，則為 true，否則為 false。

例外狀況

ArgumentNullException

keyword 為 null (在 Visual Basic 中為 Nothing)。

範例

下列範例會 SqlConnectionStringBuilder 建立 實例、設定其部分屬性，然後藉由呼叫 ContainsKey 方法，嘗試判斷物件中是否有各種索引鍵存在。

using System.Data.SqlClient;

class Program
{
    static void Main()
    {
        SqlConnectionStringBuilder builder =
            new SqlConnectionStringBuilder(GetConnectionString());
        Console.WriteLine("Connection string = " + builder.ConnectionString);

        // Keys you have provided return true.
        Console.WriteLine(builder.ContainsKey("Server"));

        // Comparison is case insensitive, and synonyms
        // are automatically converted to their "well-known"
        // names.
        Console.WriteLine(builder.ContainsKey("Database"));

        // Keys that are valid but have not been set return true.
        Console.WriteLine(builder.ContainsKey("Max Pool Size"));

        // Keys that do not exist return false.
        Console.WriteLine(builder.ContainsKey("MyKey"));

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

    private static string GetConnectionString()
    {
        // To avoid storing the connection string in your code,
        // you can retrieve it from a configuration file.
        return "Server=(local);Integrated Security=SSPI;" +
            "Initial Catalog=AdventureWorks";
    }
}

Imports System.Data.SqlClient

Module Module1
    Sub Main()
        Dim builder As _
         New SqlConnectionStringBuilder(GetConnectionString())
        Console.WriteLine("Connection string = " & builder.ConnectionString)

        ' Keys you have provided return true.
        Console.WriteLine(builder.ContainsKey("Server"))

        ' Comparison is case insensitive, and synonyms
        ' are automatically converted to their "well-known"
        ' names.
        Console.WriteLine(builder.ContainsKey("Database"))

        ' Keys that are valid but have not been set return true.
        Console.WriteLine(builder.ContainsKey("Max Pool Size"))

        ' Keys that do not exist return false.
        Console.WriteLine(builder.ContainsKey("MyKey"))

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

    Private Function GetConnectionString() As String
        ' To avoid storing the connection string in your code,
        ' you can retrieve it from a configuration file. 
        Return "Server=(local);Integrated Security=SSPI;" & _
          "Initial Catalog=AdventureWorks"
    End Function
End Module

此範例會在主控台視窗中顯示以下輸出：

Connection string = Data Source=(local);Initial Catalog=AdventureWorks;Integrated Security=True
True
True
True
False

備註

因為 SqlConnectionStringBuilder 包含固定大小的索引鍵/值組集合，所以 ContainsKey 方法只會判斷特定的索引鍵名稱是否有效。

另請參閱

• ADO.NET 中的連接字串
• ADO.NET 概觀 \(部分機器翻譯\)