DbConnectionStringBuilder.ContainsKey(String) Metodo

Riferimento

Definizione

Spazio dei nomi:: System.Data.Common

Assembly:: System.Data.Common.dll

Assembly:: System.Data.dll

Assembly:: netstandard.dll

Source:: DbConnectionStringBuilder.cs

Source:: DbConnectionStringBuilder.cs

Source:: DbConnectionStringBuilder.cs

Importante

Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.

Determina se l'oggetto DbConnectionStringBuilder contiene una chiave specifica.

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

public virtual bool ContainsKey (string keyword);

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

Public Overridable Function ContainsKey (keyword As String) As Boolean

Parametri

keyword: String

Chiave da individuare in DbConnectionStringBuilder.

Restituisce

Boolean

true se l'oggetto DbConnectionStringBuilder contiene una voce con la chiave specificata; in caso contrario, false.

Eccezioni

ArgumentNullException

keyword è un riferimento null (Nothing in Visual Basic).

Esempio

static void Main()
{
    DbConnectionStringBuilder builder = new DbConnectionStringBuilder();
    builder.Add("Provider", "Provider=Microsoft.Jet.OLEDB.4.0");
    builder.Add("Data Source", "C:\\ThisExcelWorkbook.xls");
    builder.Add("Extended Properties", "Excel 8.0;HDR=Yes;IMEX=1");

    // Displays the values in the DbConnectionStringBuilder.
    Console.WriteLine("Contents of the DbConnectionStringBuilder:");
    Console.WriteLine(builder.ConnectionString);

    // Searches for a key.
    if (builder.ContainsKey("Data Source"))
    {
        Console.WriteLine("The collection contains the key \"Data Source\".");
    }
    else
    {
        Console.WriteLine("The collection does not contain the key \"Data Source\".");
    }
    Console.ReadLine();
}

Sub Main()
    ' The following code example searches for an element in a 
    ' DbConnectionStringBuilder.
    Dim builder As New DbConnectionStringBuilder
    builder.Add("Provider", "Provider=Microsoft.Jet.OLEDB.4.0")
    builder.Add("Data Source", "C:\ThisExcelWorkbook.xls")
    builder.Add("Extended Properties", "Excel 8.0;HDR=Yes;IMEX=1")

    ' Displays the values in the DbConnectionStringBuilder.
    Console.WriteLine("Contents of the DbConnectionStringBuilder:")
    Console.WriteLine(builder.ConnectionString)

    ' Searches for a key.
    If builder.ContainsKey("Data Source") Then
        Console.WriteLine("The collection contains the key ""Data Source"".")
    Else
        Console.WriteLine("The collection does not contain the key ""Data Source"".")
    End If
    Console.ReadLine()
End Sub

Questo codice genera l'output seguente:

Contents of the DbConnectionStringBuilder:
provider="Provider=Microsoft.Jet.OLEDB.4.0";data
source=C:\MyExcel.xls;extended
properties="Excel 8.0;HDR=Yes;IMEX=1"
The collection contains the key "Data Source".

Si applica a