• Article

BitConverter.ToInt32 Method

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

Returns a 32-bit signed integer converted from four bytes at a specified position in a byte array.

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

Syntax

'Declaration
<SecuritySafeCriticalAttribute> _
Public Shared Function ToInt32 ( _
    value As Byte(), _
    startIndex As Integer _
) As Integer

[SecuritySafeCriticalAttribute]
public static int ToInt32(
    byte[] value,
    int startIndex
)

Parameters

  • startIndex
    Type: System.Int32
    The starting position within value.

Return Value

Type: System.Int32
A 32-bit signed integer formed by four bytes beginning at startIndex.

Exceptions

Exception Condition
ArgumentException

startIndex is greater than or equal to the length of value minus 3, and is less than or equal to the length of value minus 1.
ArgumentNullException

value is nulla null reference (Nothing in Visual Basic).
ArgumentOutOfRangeException

startIndex is less than zero or greater than the length of value minus 1.

Examples

The following code example converts elements of Byte arrays to Int32 values with the ToInt32 method.

' Example of the BitConverter.ToInt32 method.

Module Example

   Const formatter As String = "{0,5}{1,17}{2,15}"

   ' Convert four Byte array elements to an Integer and display it.
   Sub BAToInt32(ByVal outputBlock As System.Windows.Controls.TextBlock, ByVal bytes() As Byte, ByVal index As Integer)

      Dim value As Integer = BitConverter.ToInt32(bytes, index)

      outputBlock.Text &= String.Format(formatter, index, _
          BitConverter.ToString(bytes, index, 4), value) & vbCrLf
   End Sub

   ' Display a Byte array, using multiple lines if necessary.
   Sub WriteMultiLineByteArray(ByVal outputBlock As System.Windows.Controls.TextBlock, ByVal bytes() As Byte)

      Const rowSize As Integer = 20
      Dim iter As Integer

      outputBlock.Text &= "initial Byte array" & vbCrLf
      outputBlock.Text &= "------------------" & vbCrLf

      For iter = 0 To bytes.Length - rowSize - 1 Step rowSize
         outputBlock.Text &= String.Format( _
             BitConverter.ToString(bytes, iter, rowSize))
         outputBlock.Text &= "-" & vbCrLf
      Next iter

      outputBlock.Text &= String.Format(BitConverter.ToString(bytes, iter)) & vbCrLf
      outputBlock.Text &= vbCrLf
   End Sub

   Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      Dim byteArray As Byte() = { _
           15, 0, 0, 0, 0, 128, 0, 0, 16, 0, _
            0, 240, 255, 0, 202, 154, 59, 0, 54, 101, _
          196, 241, 255, 255, 255, 127}

      outputBlock.Text &= String.Format( _
          "This example of the BitConverter.ToInt32( Byte( ), " & _
          "Integer ) " & vbCrLf & "method generates the " & _
          "following output. It converts elements " & vbCrLf & _
          "of a Byte array to Integer values." & vbCrLf) & vbCrLf

      WriteMultiLineByteArray(outputBlock, byteArray)

      outputBlock.Text &= String.Format(formatter, "index", "array elements", _
          "Integer") & vbCrLf
      outputBlock.Text &= String.Format(formatter, "-----", "--------------", _
          "-------") & vbCrLf

      ' Convert Byte array elements to Integer values.
      BAToInt32(outputBlock, byteArray, 1)
      BAToInt32(outputBlock, byteArray, 0)
      BAToInt32(outputBlock, byteArray, 21)
      BAToInt32(outputBlock, byteArray, 6)
      BAToInt32(outputBlock, byteArray, 9)
      BAToInt32(outputBlock, byteArray, 13)
      BAToInt32(outputBlock, byteArray, 17)
      BAToInt32(outputBlock, byteArray, 22)
      BAToInt32(outputBlock, byteArray, 2)
   End Sub
End Module

' This example of the BitConverter.ToInt32( Byte( ), Integer )
' method generates the following output. It converts elements
' of a Byte array to Integer values.
' 
' initial Byte array
' ------------------
' 0F-00-00-00-00-80-00-00-10-00-00-F0-FF-00-CA-9A-3B-00-36-65-
' C4-F1-FF-FF-FF-7F
' 
' index   array elements        Integer
' -----   --------------        -------
'     1      00-00-00-00              0
'     0      0F-00-00-00             15
'    21      F1-FF-FF-FF            -15
'     6      00-00-10-00        1048576
'     9      00-00-F0-FF       -1048576
'    13      00-CA-9A-3B     1000000000
'    17      00-36-65-C4    -1000000000
'    22      FF-FF-FF-7F     2147483647
'     2      00-00-00-80    -2147483648

// Example of the BitConverter.ToInt32 method.
using System;

class Example
{
   const string formatter = "{0,5}{1,17}{2,15}";

   // Convert four byte array elements to an int and display it.
   public static void BAToInt32(System.Windows.Controls.TextBlock outputBlock, byte[] bytes, int index)
   {
      int value = BitConverter.ToInt32(bytes, index);

      outputBlock.Text += String.Format(formatter, index,
          BitConverter.ToString(bytes, index, 4), value) + "\n";
   }

   // Display a byte array, using multiple lines if necessary.
   public static void WriteMultiLineByteArray(System.Windows.Controls.TextBlock outputBlock, byte[] bytes)
   {
      const int rowSize = 20;
      int iter;

      outputBlock.Text += "initial byte array" + "\n";
      outputBlock.Text += "------------------" + "\n";

      for (iter = 0; iter < bytes.Length - rowSize; iter += rowSize)
      {
         outputBlock.Text += String.Format(
             BitConverter.ToString(bytes, iter, rowSize));
         outputBlock.Text += "-" + "\n";
      }

      outputBlock.Text += String.Format(BitConverter.ToString(bytes, iter)) + "\n";
      outputBlock.Text += "\n";
   }

   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      byte[] byteArray = {
             15,   0,   0,   0,   0, 128,   0,   0,  16,   0, 
              0, 240, 255,   0, 202, 154,  59,   0,  54, 101, 
            196, 241, 255, 255, 255, 127 };

      outputBlock.Text += String.Format(
          "This example of the BitConverter.ToInt32( byte[ ], " +
          "int ) \nmethod generates the following output. It " +
          "converts elements \nof a byte array to int values.\n") + "\n";

      WriteMultiLineByteArray(outputBlock, byteArray);

      outputBlock.Text += String.Format(formatter, "index", "array elements",
          "int") + "\n";
      outputBlock.Text += String.Format(formatter, "-----", "--------------",
          "---") + "\n";

      // Convert byte array elements to int values.
      BAToInt32(outputBlock, byteArray, 1);
      BAToInt32(outputBlock, byteArray, 0);
      BAToInt32(outputBlock, byteArray, 21);
      BAToInt32(outputBlock, byteArray, 6);
      BAToInt32(outputBlock, byteArray, 9);
      BAToInt32(outputBlock, byteArray, 13);
      BAToInt32(outputBlock, byteArray, 17);
      BAToInt32(outputBlock, byteArray, 22);
      BAToInt32(outputBlock, byteArray, 2);
   }
}

/*
This example of the BitConverter.ToInt32( byte[ ], int )
method generates the following output. It converts elements
of a byte array to int values.

initial byte array
------------------
0F-00-00-00-00-80-00-00-10-00-00-F0-FF-00-CA-9A-3B-00-36-65-
C4-F1-FF-FF-FF-7F

index   array elements            int
-----   --------------            ---
    1      00-00-00-00              0
    0      0F-00-00-00             15
   21      F1-FF-FF-FF            -15
    6      00-00-10-00        1048576
    9      00-00-F0-FF       -1048576
   13      00-CA-9A-3B     1000000000
   17      00-36-65-C4    -1000000000
   22      FF-FF-FF-7F     2147483647
    2      00-00-00-80    -2147483648
*/

Version Information

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

Platforms

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