C# 数组 比较

 

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Drawing;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;


/// <summary>
    /// 用memcmp比较字节数组
    /// </summary>
    /// <param name="b1">字节数组1</param>
    /// <param name="b2">字节数组2</param>
    /// <returns>如果两个数组相同，返回0；如果数组1小于数组2，返回小于0的值；如果数组1大于数组2，返回大于0的值。</returns>
    public static int MemoryCompare(byte[] b1, byte[] b2)
    {
        IntPtr retval = memcmp(b1, b2, new IntPtr(b1.Length));
        return retval.ToInt32();
    }

    /// <summary>
    /// 比较字节数组
    /// </summary>
    /// <param name="b1">字节数组1</param>
    /// <param name="b2">字节数组2</param>
    /// <returns>如果两个数组相同，返回0；如果数组1小于数组2，返回小于0的值；如果数组1大于数组2，返回大于0的值。</returns>
    public static int MemoryCompare2(byte[] b1, byte[] b2)
    {
        int result = 0;
        if (b1.Length != b2.Length)
            result = b1.Length - b2.Length;
        else
        {
            for (int i = 0; i < b1.Length; i++)
            {
                if (b1[i] != b2[i])
                {
                    result = (int)(b1[i] - b2[i]);
                    break;
                }
            }
        }
        return result;
    }

    /// <summary>
    /// memcmp API
    /// </summary>
    /// <param name="b1">字节数组1</param>
    /// <param name="b2">字节数组2</param>
    /// <returns>如果两个数组相同，返回0；如果数组1小于数组2，返回小于0的值；如果数组1大于数组2，返回大于0的值。</returns>
    [DllImport("msvcrt.dll")]
    private static extern IntPtr memcmp(byte[] b1, byte[] b2, IntPtr count);
}