using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Drawing;
using System.IO;
namespace test_CS_1
{
    class Program
    {

        static void Main(string[] args)
        {
          
            
            string fileDir = "E:/DX12/Sketch3DToolkit-master/matlab/";
            //文件名称
            string filePath = Path.Combine(fileDir, "new");
            string UserPhoto;
           

            //读图片转为Base64String
            System.Drawing.Bitmap bmp1 = new System.Drawing.Bitmap(Path.Combine(fileDir, "2.png"));
            using (MemoryStream ms1 = new MemoryStream())
            {
                //将文件指定格式保存到指定流中
                bmp1.Save(ms1, System.Drawing.Imaging.ImageFormat.Png);
                byte[] arr1 = new byte[ms1.Length];
                ms1.Position = 0;
                //从当前流读取字节块，并写入缓存区
                ms1.Read(arr1, 0, (int)ms1.Length);
                ms1.Close();
                //将缓存区数据byte[],转为base64string
                UserPhoto = Convert.ToBase64String(arr1);
            }

            //将Base64String转为图片并保存
            byte[] arr2 = Convert.FromBase64String(UserPhoto);
            using (MemoryStream ms2 = new MemoryStream(arr2))
            {
                System.Drawing.Bitmap bmp2 = new System.Drawing.Bitmap(ms2);
                //以指定格式保存到指定文件
                bmp2.Save(filePath + ".png", System.Drawing.Imaging.ImageFormat.Png);
              
            }

        }
    }
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System;
using System.IO;

public class test_texture2d : MonoBehaviour {

    // Use this for initialization
    //base64转图片
    public string Base64ToTexture2d(string Base64STR)
    {
        Texture2D pic = new Texture2D(1111, 1111);
        byte[] data = System.Convert.FromBase64String(Base64STR);
        pic.LoadImage(data);
        byte[] bytes = pic.EncodeToPNG();

        //下面是为了方便了解图片的信息写的
        string year = System.DateTime.Now.Year.ToString();
        string month = System.DateTime.Now.Month.ToString();
        string day = System.DateTime.Now.Day.ToString();
        string hour = System.DateTime.Now.Hour.ToString();
        string minute = System.DateTime.Now.Minute.ToString();
        string secend = System.DateTime.Now.Second.ToString();
        //存储路径
        string FileFullPath = Application.dataPath/*这是获取assets前的文件路径*/ + "/" + year + "-" + month + "-" + day + "-" + hour + "-" + minute + "-" + secend + ".png";


        File.WriteAllBytes(FileFullPath, bytes);
        return FileFullPath;
    }
    //图片转base64string
    public string Texture2dToBase64(string texture2d_path)
    {
        //将图片文件转为流文件
        FileStream fs = new System.IO.FileStream(texture2d_path, System.IO.FileMode.Open, System.IO.FileAccess.Read);
        byte[] thebytes = new byte[fs.Length];

        fs.Read(thebytes, 0, (int)fs.Length);
        //转为base64string
        string base64_texture2d = Convert.ToBase64String(thebytes);
        return base64_texture2d;
    }
    void Start () {


       
    }
    
    // Update is called once per frame
    void Update () {
        
    }
}