StringBuilder.EnsureCapacity(Int32) メソッド

定義

このインスタンスの StringBuilder の容量が、指定した値以上になるようにします。Ensures that the capacity of this instance of StringBuilder is at least the specified value.

public:
 int EnsureCapacity(int capacity);
public int EnsureCapacity (int capacity);
member this.EnsureCapacity : int -> int
Public Function EnsureCapacity (capacity As Integer) As Integer

パラメーター

capacity
Int32

必要な最小容量。The minimum capacity to ensure.

戻り値

このインスタンスの新しい容量。The new capacity of this instance.

例外

capacity が 0 未満です。capacity is less than zero.

または-or- このインスタンスの値を増やすと MaxCapacity を超えます。Enlarging the value of this instance would exceed MaxCapacity.

メソッドのEnsureCapacity例を次に示します。The following example demonstrates the EnsureCapacity method.

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
*/
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

注釈

現在の容量がcapacityパラメーターよりも小さい場合、このインスタンスのメモリは少なくcapacityとも文字数を保持するように再割り当てされます。それ以外の場合は、メモリは変更されません。If the current capacity is less than the capacity parameter, memory for this instance is reallocated to hold at least capacity number of characters; otherwise, no memory is changed.

適用対象