StringBuilder.Capacity Property

Gets or sets the maximum number of characters that can be contained in the memory allocated by the current instance.

Namespace:  System.Text
Assembly:  mscorlib (in mscorlib.dll)

'Declaration
Public Property Capacity As Integer

Property Value

Type: System.Int32
The maximum number of characters that can be contained in the memory allocated by the current instance.

ExceptionCondition
ArgumentOutOfRangeException

The value specified for a set operation is less than the current length of this instance.

-or-

The value specified for a set operation is greater than the maximum capacity.

Capacity does not affect the string value of the current instance. Capacity can be decreased as long as it is not less than Length.

The StringBuilder dynamically allocates more space when required and increases Capacity accordingly. For performance reasons, a StringBuilder might allocate more memory than needed. The amount of memory allocated is implementation-specific.

The following code example demonstrates the Capacity property.


Imports System.Text

Class Example
   Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      Dim sb1 As New StringBuilder("abc")
      Dim sb2 As New StringBuilder("abc", 16)

      outputBlock.Text &= vbCrLf
      outputBlock.Text += String.Format("a1) sb1.Length = {0}, sb1.Capacity = {1}", sb1.Length, sb1.Capacity) & vbCrLf
      outputBlock.Text += String.Format("a2) sb2.Length = {0}, sb2.Capacity = {1}", sb2.Length, sb2.Capacity) & vbCrLf
      outputBlock.Text += String.Format("a3) sb1.ToString() = ""{0}"", sb2.ToString() & vbCrLf = ""{1}""", _
                             sb1.ToString(), sb2.ToString())
      outputBlock.Text += String.Format("a4) sb1 equals sb2: {0}", sb1.Equals(sb2)) & vbCrLf

      outputBlock.Text &= vbCrLf
      outputBlock.Text &= "Ensure sb1 has a capacity of at least 50 characters." & vbCrLf
      sb1.EnsureCapacity(50)

      outputBlock.Text &= vbCrLf
      outputBlock.Text += String.Format("b1) sb1.Length = {0}, sb1.Capacity = {1}", sb1.Length, sb1.Capacity) & vbCrLf
      outputBlock.Text += String.Format("b2) sb2.Length = {0}, sb2.Capacity = {1}", sb2.Length, sb2.Capacity) & vbCrLf
      outputBlock.Text += String.Format("b3) sb1.ToString() = ""{0}"", sb2.ToString() & vbCrLf = ""{1}""", _
                             sb1.ToString(), sb2.ToString())
      outputBlock.Text += String.Format("b4) sb1 equals sb2: {0}", sb1.Equals(sb2)) & vbCrLf

      outputBlock.Text &= vbCrLf
      outputBlock.Text &= "Set the length of sb1 to zero." & vbCrLf
      outputBlock.Text &= "Set the capacity of sb2 to 51 characters." & vbCrLf
      sb1.Length = 0
      sb2.Capacity = 51

      outputBlock.Text &= vbCrLf
      outputBlock.Text += String.Format("c1) sb1.Length = {0}, sb1.Capacity = {1}", sb1.Length, sb1.Capacity) & vbCrLf
      outputBlock.Text += String.Format("c2) sb2.Length = {0}, sb2.Capacity = {1}", sb2.Length, sb2.Capacity) & vbCrLf
      outputBlock.Text += String.Format("c3) sb1.ToString() = ""{0}"", sb2.ToString() & vbCrLf = ""{1}""", _
                             sb1.ToString(), sb2.ToString())
      outputBlock.Text += String.Format("c4) sb1 equals sb2: {0}", sb1.Equals(sb2)) & vbCrLf
   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


Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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