using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Runtime.Serialization.Json;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System.Web.Services.Protocols;
using System.Security.Cryptography;
using System.Text;
using System.Web.SessionState;
using System.Data;
using System.Drawing.Imaging;
using System.Drawing;
using System.IO;
using System.Data.SqlClient;
using System.Configuration;

public static class globalClass
{
    public static string CreateRandomCode(int Number)
    {
        string allChar = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z";
        string[] allCharArray = allChar.Split(',');
        string randomCode = "";

        Random rand = new Random(Guid.NewGuid().GetHashCode());
        for (int i = 0; i <= Number - 1; i++)
        {
            int t = rand.Next(allCharArray.Length);
            randomCode += allCharArray[t];
        }
        return randomCode;
    }

    public static string appsettings(string key)
    {

        return ConfigurationManager.ConnectionStrings[key].ConnectionString;
    }

    public static string SHA256_Encode(string value)
    {
        byte[] bytValue = System.Text.Encoding.UTF8.GetBytes(value);
        try
        {
            SHA256 sha256 = new SHA256CryptoServiceProvider();
            byte[] retVal = sha256.ComputeHash(bytValue);
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < retVal.Length; i++)
            {
                sb.Append(retVal[i].ToString("x2"));
            }
            return sb.ToString();
        }
        catch (Exception ex)
        {
            throw new Exception("GetSHA256HashFromString() fail,error:" + ex.Message);
        }

    }

}