Windows apps
Collapse the table of content
Expand the table of content
The topic you requested is included in another documentation set. For convenience, it's displayed below. Choose Switch to see the topic in its original location.

BitConverter.ToInt32 Method

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)

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


Type: System.Byte[]
An array of bytes.
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.


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.


value is null.


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

The ToInt32 method converts the bytes from index startIndex to startIndex + 3 to an Int32 value. The order of bytes in the array must reflect the endianness of the computer system's architecture; for more information, see the Remarks section of BitConverter.

The following example uses the ToInt32 method to create Int32 values from a four-byte array and from the upper four bytes of an eight-byte array. It also uses the GetBytes and ToInt32 methods to round-trip an Int32 value.

using System;

public class Example
   public static void Main()
      // Create an Integer from a 4-byte array.
      Byte[] bytes1 = { 0xEC, 0x00, 0x00, 0x00 };
      Console.WriteLine("{0}--> 0x{1:X4} ({1:N0})", FormatBytes(bytes1),
                                      BitConverter.ToInt32(bytes1, 0));
      // Create an Integer from the upper four bytes of a byte array.
      Byte[] bytes2 = BitConverter.GetBytes(Int64.MaxValue / 2);
      Console.WriteLine("{0}--> 0x{1:X4} ({1:N0})", FormatBytes(bytes2),
                                      BitConverter.ToInt32(bytes2, 4));

      // Round-trip an integer value.
      int original = (int) Math.Pow(16, 3);
      Byte[] bytes3 = BitConverter.GetBytes(original);
      int restored = BitConverter.ToInt32(bytes3, 0);
      Console.WriteLine("0x{0:X4} ({0:N0}) --> {1} --> 0x{2:X4} ({2:N0})", original, 
                        FormatBytes(bytes3), restored);

   private static string FormatBytes(Byte[] bytes)
       string value = "";
       foreach (var byt in bytes)
          value += String.Format("{0:X2} ", byt);

       return value;
// The example displays the following output:
//       EC 00 00 00 --> 0x00EC (236)
//       FF FF FF FF FF FF FF 3F --> 0x3FFFFFFF (1,073,741,823)
//       0x1000 (4,096) --> 00 10 00 00  --> 0x1000 (4,096)

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Community Additions

© 2017 Microsoft