StringBuilder.Length Proprietà
Definizione
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.
Ottiene o imposta la lunghezza dell'oggetto StringBuilder corrente.
public:
property int Length { int get(); void set(int value); };public int Length { get; set; }member this.Length : int with get, setPublic Property Length As IntegerValore della proprietà
Lunghezza di questa istanza.
Eccezioni
Il valore specificato per un'operazione set è minore di zero o maggiore di MaxCapacity.
Esempio
Nell'esempio seguente viene illustrata la Length proprietà .
using namespace System;
using namespace System::Text;
int main()
{
StringBuilder^ sb1 = gcnew StringBuilder( "abc" );
StringBuilder^ sb2 = gcnew StringBuilder( "abc",16 );
Console::WriteLine();
Console::WriteLine( "a1) sb1->Length = {0}, sb1->Capacity = {1}", sb1->Length, sb1->Capacity );
Console::WriteLine( "a2) sb2->Length = {0}, sb2->Capacity = {1}", sb2->Length, sb2->Capacity );
Console::WriteLine( "a3) sb1 = \"{0}\", sb2 = \"{1}\"", sb1, sb2 );
Console::WriteLine( "a4) sb1 equals sb2: {0}", sb1->Equals( sb2 ) );
Console::WriteLine();
Console::WriteLine( "Ensure sb1 has a capacity of at least 50 characters." );
sb1->EnsureCapacity( 50 );
Console::WriteLine();
Console::WriteLine( "b1) sb1->Length = {0}, sb1->Capacity = {1}", sb1->Length, sb1->Capacity );
Console::WriteLine( "b2) sb2->Length = {0}, sb2->Capacity = {1}", sb2->Length, sb2->Capacity );
Console::WriteLine( "b3) sb1 = \"{0}\", sb2 = \"{1}\"", sb1, sb2 );
Console::WriteLine( "b4) sb1 equals sb2: {0}", sb1->Equals( sb2 ) );
Console::WriteLine();
Console::WriteLine( "Set the length of sb1 to zero." );
Console::WriteLine( "Set the capacity of sb2 to 51 characters." );
sb1->Length = 0;
sb2->Capacity = 51;
Console::WriteLine();
Console::WriteLine( "c1) sb1->Length = {0}, sb1->Capacity = {1}", sb1->Length, sb1->Capacity );
Console::WriteLine( "c2) sb2->Length = {0}, sb2->Capacity = {1}", sb2->Length, sb2->Capacity );
Console::WriteLine( "c3) sb1 = \"{0}\", sb2 = \"{1}\"", sb1, sb2 );
Console::WriteLine( "c4) sb1 equals sb2: {0}", sb1->Equals( sb2 ) );
}
/*
The example displays the following output:
a1) sb1->Length = 3, sb1->Capacity = 16
a2) sb2->Length = 3, sb2->Capacity = 16
a3) sb1 = "abc", sb2 = "abc"
a4) sb1 equals sb2: True
Ensure sb1 has a capacity of at least 50 characters.
b1) sb1->Length = 3, sb1->Capacity = 50
b2) sb2->Length = 3, sb2->Capacity = 16
b3) sb1 = "abc", sb2 = "abc"
b4) sb1 equals sb2: False
Set the length of sb1 to zero.
Set the capacity of sb2 to 51 characters.
c1) sb1->Length = 0, sb1->Capacity = 50
c2) sb2->Length = 3, sb2->Capacity = 51
c3) sb1 = "", sb2 = "abc"
c4) sb1 equals sb2: False
*/
using System;
using System.Text;
class Sample
{
public static void Main()
{
StringBuilder sb1 = new StringBuilder("abc");
StringBuilder sb2 = new StringBuilder("abc", 16);
Console.WriteLine();
Console.WriteLine("a1) sb1.Length = {0}, sb1.Capacity = {1}", sb1.Length, sb1.Capacity);
Console.WriteLine("a2) sb2.Length = {0}, sb2.Capacity = {1}", sb2.Length, sb2.Capacity);
Console.WriteLine("a3) sb1.ToString() = \"{0}\", sb2.ToString() = \"{1}\"",
sb1.ToString(), sb2.ToString());
Console.WriteLine("a4) sb1 equals sb2: {0}", sb1.Equals(sb2));
Console.WriteLine();
Console.WriteLine("Ensure sb1 has a capacity of at least 50 characters.");
sb1.EnsureCapacity(50);
Console.WriteLine();
Console.WriteLine("b1) sb1.Length = {0}, sb1.Capacity = {1}", sb1.Length, sb1.Capacity);
Console.WriteLine("b2) sb2.Length = {0}, sb2.Capacity = {1}", sb2.Length, sb2.Capacity);
Console.WriteLine("b3) sb1.ToString() = \"{0}\", sb2.ToString() = \"{1}\"",
sb1.ToString(), sb2.ToString());
Console.WriteLine("b4) sb1 equals sb2: {0}", sb1.Equals(sb2));
Console.WriteLine();
Console.WriteLine("Set the length of sb1 to zero.");
Console.WriteLine("Set the capacity of sb2 to 51 characters.");
sb1.Length = 0;
sb2.Capacity = 51;
Console.WriteLine();
Console.WriteLine("c1) sb1.Length = {0}, sb1.Capacity = {1}", sb1.Length, sb1.Capacity);
Console.WriteLine("c2) sb2.Length = {0}, sb2.Capacity = {1}", sb2.Length, sb2.Capacity);
Console.WriteLine("c3) sb1.ToString() = \"{0}\", sb2.ToString() = \"{1}\"",
sb1.ToString(), sb2.ToString());
Console.WriteLine("c4) sb1 equals sb2: {0}", sb1.Equals(sb2));
}
}
/*
The example displays the following output:
a1) sb1.Length = 3, sb1.Capacity = 16
a2) sb2.Length = 3, sb2.Capacity = 16
a3) sb1.ToString() = "abc", sb2.ToString() = "abc"
a4) sb1 equals sb2: True
Ensure sb1 has a capacity of at least 50 characters.
b1) sb1.Length = 3, sb1.Capacity = 50
b2) sb2.Length = 3, sb2.Capacity = 16
b3) sb1.ToString() = "abc", sb2.ToString() = "abc"
b4) sb1 equals sb2: False
Set the length of sb1 to zero.
Set the capacity of sb2 to 51 characters.
c1) sb1.Length = 0, sb1.Capacity = 50
c2) sb2.Length = 3, sb2.Capacity = 51
c3) sb1.ToString() = "", sb2.ToString() = "abc"
c4) sb1 equals sb2: False
*/
open System.Text
let sb1 = StringBuilder "abc"
let sb2 = StringBuilder("abc", 16)
printfn $"a1) sb1.Length = {sb1.Length}, sb1.Capacity = {sb1.Capacity}"
printfn $"a2) sb2.Length = {sb2.Length}, sb2.Capacity = {sb2.Capacity}"
printfn $"a3) sb1.ToString() = \"{sb1}\", sb2.ToString() = \"{sb2}\""
printfn $"a4) sb1 equals sb2: {sb1.Equals sb2}"
printfn "\nEnsure sb1 has a capacity of at least 50 characters."
sb1.EnsureCapacity 50 |> ignore
printfn $"\nb1) sb1.Length = {sb1.Length}, sb1.Capacity = {sb1.Capacity}"
printfn $"b2) sb2.Length = {sb2.Length}, sb2.Capacity = {sb2.Capacity}"
printfn $"b3) sb1.ToString() = \"{sb1}\", sb2.ToString() = \"{sb2}\""
printfn $"b4) sb1 equals sb2: {sb1.Equals sb2}"
printfn "\nSet the length of sb1 to zero."
printfn "Set the capacity of sb2 to 51 characters."
sb1.Length <- 0
sb2.Capacity <- 51
printfn $"\nc1) sb1.Length = {sb1.Length}, sb1.Capacity = {sb1.Capacity}"
printfn $"c2) sb2.Length = {sb2.Length}, sb2.Capacity = {sb2.Capacity}"
printfn $"c3) sb1.ToString() = \"{sb1}\", sb2.ToString() = \"{sb2}\""
printfn $"c4) sb1 equals sb2: {sb1.Equals sb2}"
// The example displays the following output:
// a1) sb1.Length = 3, sb1.Capacity = 16
// a2) sb2.Length = 3, sb2.Capacity = 16
// a3) sb1.ToString() = "abc", sb2.ToString() = "abc"
// a4) sb1 equals sb2: True
//
// Ensure sb1 has a capacity of at least 50 characters.
//
// b1) sb1.Length = 3, sb1.Capacity = 50
// b2) sb2.Length = 3, sb2.Capacity = 16
// b3) sb1.ToString() = "abc", sb2.ToString() = "abc"
// b4) sb1 equals sb2: False
//
// Set the length of sb1 to zero.
// Set the capacity of sb2 to 51 characters.
//
// c1) sb1.Length = 0, sb1.Capacity = 50
// c2) sb2.Length = 3, sb2.Capacity = 51
// c3) sb1.ToString() = "", sb2.ToString() = "abc"
// c4) sb1 equals sb2: False
Imports System.Text
Class Sample
Public Shared Sub Main()
Dim sb1 As New StringBuilder("abc")
Dim sb2 As New StringBuilder("abc", 16)
Console.WriteLine()
Console.WriteLine("a1) sb1.Length = {0}, sb1.Capacity = {1}", sb1.Length, sb1.Capacity)
Console.WriteLine("a2) sb2.Length = {0}, sb2.Capacity = {1}", sb2.Length, sb2.Capacity)
Console.WriteLine("a3) sb1.ToString() = ""{0}"", sb2.ToString() = ""{1}""", _
sb1.ToString(), sb2.ToString())
Console.WriteLine("a4) sb1 equals sb2: {0}", sb1.Equals(sb2))
Console.WriteLine()
Console.WriteLine("Ensure sb1 has a capacity of at least 50 characters.")
sb1.EnsureCapacity(50)
Console.WriteLine()
Console.WriteLine("b1) sb1.Length = {0}, sb1.Capacity = {1}", sb1.Length, sb1.Capacity)
Console.WriteLine("b2) sb2.Length = {0}, sb2.Capacity = {1}", sb2.Length, sb2.Capacity)
Console.WriteLine("b3) sb1.ToString() = ""{0}"", sb2.ToString() = ""{1}""", _
sb1.ToString(), sb2.ToString())
Console.WriteLine("b4) sb1 equals sb2: {0}", sb1.Equals(sb2))
Console.WriteLine()
Console.WriteLine("Set the length of sb1 to zero.")
Console.WriteLine("Set the capacity of sb2 to 51 characters.")
sb1.Length = 0
sb2.Capacity = 51
Console.WriteLine()
Console.WriteLine("c1) sb1.Length = {0}, sb1.Capacity = {1}", sb1.Length, sb1.Capacity)
Console.WriteLine("c2) sb2.Length = {0}, sb2.Capacity = {1}", sb2.Length, sb2.Capacity)
Console.WriteLine("c3) sb1.ToString() = ""{0}"", sb2.ToString() = ""{1}""", _
sb1.ToString(), sb2.ToString())
Console.WriteLine("c4) sb1 equals sb2: {0}", sb1.Equals(sb2))
End Sub
End Class
'The example displays the following output:
' a1) sb1.Length = 3, sb1.Capacity = 16
' a2) sb2.Length = 3, sb2.Capacity = 16
' a3) sb1.ToString() = "abc", sb2.ToString() = "abc"
' a4) sb1 equals sb2: True
'
' Ensure sb1 has a capacity of at least 50 characters.
'
' b1) sb1.Length = 3, sb1.Capacity = 50
' b2) sb2.Length = 3, sb2.Capacity = 16
' b3) sb1.ToString() = "abc", sb2.ToString() = "abc"
' b4) sb1 equals sb2: False
'
' Set the length of sb1 to zero.
' Set the capacity of sb2 to 51 characters.
'
' c1) sb1.Length = 0, sb1.Capacity = 50
' c2) sb2.Length = 3, sb2.Capacity = 51
' c3) sb1.ToString() = "", sb2.ToString() = "abc"
' c4) sb1 equals sb2: False
Commenti
La lunghezza di un StringBuilder oggetto è definita dal numero di Char oggetti.
Analogamente alla proprietà, la String.LengthLength proprietà indica la lunghezza dell'oggetto stringa corrente. String.Length A differenza della proprietà, che è di sola lettura, la Length proprietà consente di modificare la lunghezza della stringa archiviata nell'oggettoStringBuilder.
Se la lunghezza specificata è minore della lunghezza corrente, l'oggetto corrente StringBuilder viene troncato alla lunghezza specificata. Se la lunghezza specificata è maggiore della lunghezza corrente, la fine del valore stringa dell'oggetto corrente StringBuilder viene riempita con il carattere UNICODE NULL (U+0000).
Se la lunghezza specificata è maggiore della capacità corrente, Capacity aumenta in modo che sia maggiore o uguale alla lunghezza specificata.
Si applica a
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