项目
11/18/2011

StringBuilder.Clear Method

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Removes all characters from the current StringBuilder instance.

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

Syntax

'Declaration
Public Function Clear As StringBuilder

public StringBuilder Clear()

Return Value

Type: System.Text.StringBuilder
An object whose Length is 0 (zero).

Remarks

Clear is a convenience method that is equivalent to setting the Length property of the current instance to 0 (zero).

Examples

The following example instantiates a StringBuilder object with a string, calls the Clear method, and then appends a new string.

Imports System.Text

Module Example
   Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      Dim sb As New StringBuilder("This is a string.")
      outputBlock.Text += String.Format("{0} ({1} characters)", sb.ToString(), sb.Length) & vbCrLf

      sb.Clear()
      outputBlock.Text += String.Format("{0} ({1} characters)", sb.ToString(), sb.Length) & vbCrLf

      sb.Append("This is a second string.")
      outputBlock.Text += String.Format("{0} ({1} characters)", sb.ToString(), sb.Length) & vbCrLf
   End Sub
End Module
' The example displays the following output:
'       This is a string. (17 characters)
'        (0 characters)
'       This is a second string. (24 characters)

using System;
using System.Text;

public class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      StringBuilder sb = new StringBuilder("This is a string.");
      outputBlock.Text += String.Format("{0} ({1} characters)", sb.ToString(), sb.Length) + "\n";

      sb.Clear();
      outputBlock.Text += String.Format("{0} ({1} characters)", sb.ToString(), sb.Length) + "\n";

      sb.Append("This is a second string.");
      outputBlock.Text += String.Format("{0} ({1} characters)", sb.ToString(), sb.Length) + "\n";
   }
}
// The example displays the following output:
//       This is a string. (17 characters)
//        (0 characters)
//       This is a second string. (24 characters)

Version Information

Silverlight

Supported in: 5, 4

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1

Platforms

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

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