Condividi tramite


DataTable.CaseSensitive Proprietà

Definizione

Indica se i confronti tra stringhe all'interno della tabella fanno distinzione tra maiuscole e minuscole.

public:
 property bool CaseSensitive { bool get(); void set(bool value); };
public bool CaseSensitive { get; set; }
[System.Data.DataSysDescription("DataTableCaseSensitiveDescr")]
public bool CaseSensitive { get; set; }
member this.CaseSensitive : bool with get, set
[<System.Data.DataSysDescription("DataTableCaseSensitiveDescr")>]
member this.CaseSensitive : bool with get, set
Public Property CaseSensitive As Boolean

Valore della proprietà

true se il confronto fa distinzione tra maiuscole e minuscole; in caso contrario false, . Il valore predefinito è impostato sulla proprietà dell'oggetto CaseSensitive padre DataSet o false se DataTable è stato creato indipendentemente da un oggetto DataSet.

Attributi

Esempio

Nell'esempio seguente viene chiamato il Select metodo due volte su un oggetto DataTable. La prima volta, la CaseSensitive proprietà viene impostata su false, la seconda su true.

private static void ToggleCaseSensitive()
{
    DataTable t;
    DataRow[] foundRows;

    t = CreateDataSet().Tables[0];

    t.CaseSensitive = false;
    foundRows = t.Select("item = 'abc'");

    // Print out DataRow values.
    PrintRowValues(foundRows, "CaseSensitive = False");

    t.CaseSensitive = true;
    foundRows = t.Select("item = 'abc'");

    PrintRowValues(foundRows, "CaseSensitive = True");
}

public static DataSet CreateDataSet()
{
    // Create a DataSet with one table, two columns
    DataSet ds = new DataSet();
    DataTable t = new DataTable("Items");

    // Add table to dataset
    ds.Tables.Add(t);

    // Add two columns
    DataColumn c;

    // First column
    c = t.Columns.Add("id", typeof(int));
    c.AutoIncrement = true;

    // Second column
    t.Columns.Add("item", typeof(string));

    // Set primary key
    t.PrimaryKey = new DataColumn[] { t.Columns["id"] };

    // Add twelve rows
    for (int i = 0; i < 10; i++)
    {
        t.Rows.Add(new object[] { i, i.ToString() });
    }
    t.Rows.Add(new object[] { 11, "abc" });
    t.Rows.Add(new object[] { 15, "ABC" });

    return ds;
}

private static void PrintRowValues(DataRow[] rows, string label)
{
    Console.WriteLine();
    Console.WriteLine(label);
    if (rows.Length <= 0)
    {
        Console.WriteLine("no rows found");
        return;
    }
    foreach (DataRow r in rows)
    {
        foreach (DataColumn c in r.Table.Columns)
        {
            Console.Write("\t {0}", r[c]);
        }
        Console.WriteLine();
    }
}

Private Sub ToggleCaseSensitive()
    Dim t As DataTable
    Dim foundRows() As DataRow

    t = CreateDataSet().Tables(0)

    t.CaseSensitive = False
    foundRows = t.Select("item = 'abc'")

    ' Print out DataRow values. Row 0 contains the value we're looking for.
    PrintRowValues(foundRows, "CaseSensitive = False")

    t.CaseSensitive = True
    foundRows = t.Select("item = 'abc'")

    PrintRowValues(foundRows, "CaseSensitive = True")
End Sub

Public Function CreateDataSet() As DataSet
    ' Create a DataSet with one table, two columns
    Dim ds As New DataSet
    Dim t As New DataTable("Items")

    ' Add table to DataSet
    ds.Tables.Add(t)

    ' Add two columns
    Dim c As DataColumn

    ' First column
    c = t.Columns.Add("id", Type.GetType("System.Int32"))
    c.AutoIncrement = True

    ' Second column
    t.Columns.Add("item", Type.GetType("System.String"))

    ' Set primary key
    t.PrimaryKey = New DataColumn() {t.Columns("id")}

    For i As Integer = 0 To 9
        t.Rows.Add(New Object() {i, i.ToString()})
    Next
    t.Rows.Add(New Object() {11, "abc"})
    t.Rows.Add(New Object() {15, "ABC"})

    CreateDataSet = ds
End Function

Private Sub PrintRowValues(ByRef rows As DataRow(), ByVal label As String)
    Console.WriteLine()
    Console.WriteLine(label)
    If rows.Length <= 0 Then
        Console.WriteLine("no rows found")
        Return
    End If

    For Each r As DataRow In rows
        For Each c As DataColumn In r.Table.Columns
            Console.Write(vbTab & " {0}", r(c))
        Next
        Console.WriteLine()
    Next
End Sub

Commenti

La CaseSensitive proprietà influisce sui confronti tra stringhe nell'ordinamento, nella ricerca e nel filtro.

Si applica a

Vedi anche