C# 拖拽拉伸图片裁剪选框

在PictureBox控件内建立可移动的矩形选框裁剪图片的panel 实现了panel在picturebox上移动且透明，可自由拉伸移动，总共代码只有80行，简单易懂。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace WindowsFormsApp1
{
    public class BaiDuTokenModel
    {
        public string refresh_token { get; set; }
        public int expires_in { get; set; }
        public string session_key { get; set; }
        public string access_token { get; set; }
        public string scope { get; set; }
        public string session_secret { get; set; }
    }
}

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----
     文件      173711  2019-02-04 20:31  Demo1.png
     目录           0  2019-02-04 20:14  WindowsFormsApp1\
     目录           0  2019-02-04 20:11  WindowsFormsApp1\.vs\
     目录           0  2019-02-04 20:11  WindowsFormsApp1\.vs\WindowsFormsApp1\
     目录           0  2019-02-04 20:11  WindowsFormsApp1\.vs\WindowsFormsApp1\v15\
     文件       39424  2019-02-04 20:31  WindowsFormsApp1\.vs\WindowsFormsApp1\v15\.suo
     目录           0  2019-02-04 20:11  WindowsFormsApp1\.vs\WindowsFormsApp1\v15\Server\
     目录           0  2019-02-04 20:11  WindowsFormsApp1\.vs\WindowsFormsApp1\v15\Server\sqlite3\
     文件           0  2019-02-04 20:11  WindowsFormsApp1\.vs\WindowsFormsApp1\v15\Server\sqlite3\db.lock
     文件      667648  2019-02-04 20:06  WindowsFormsApp1\.vs\WindowsFormsApp1\v15\Server\sqlite3\storage.ide
     文件       32768  2019-02-04 20:11  WindowsFormsApp1\.vs\WindowsFormsApp1\v15\Server\sqlite3\storage.ide-shm
     文件     4124152  2019-02-04 20:31  WindowsFormsApp1\.vs\WindowsFormsApp1\v15\Server\sqlite3\storage.ide-wal
     文件       18810  2019-02-04 20:14  WindowsFormsApp1\1.jpeg
     目录           0  2019-02-04 20:30  WindowsFormsApp1\WindowsFormsApp1\
     文件         187  2019-02-03 22:06  WindowsFormsApp1\WindowsFormsApp1\App.config
     文件         498  2019-02-03 22:40  WindowsFormsApp1\WindowsFormsApp1\BaiDuTokenModel.cs
     文件        5635  2019-02-04 20:30  WindowsFormsApp1\WindowsFormsApp1\Form1.Designer.cs
     文件        2347  2019-02-04 20:30  WindowsFormsApp1\WindowsFormsApp1\Form1.cs
     文件        6022  2019-02-04 20:30  WindowsFormsApp1\WindowsFormsApp1\Form1.resx
     文件         528  2019-02-03 22:06  WindowsFormsApp1\WindowsFormsApp1\Program.cs
     目录           0  2019-02-04 20:15  WindowsFormsApp1\WindowsFormsApp1\Properties\
     文件        1330  2019-02-03 22:06  WindowsFormsApp1\WindowsFormsApp1\Properties\AssemblyInfo.cs
     文件        3228  2019-02-04 20:15  WindowsFormsApp1\WindowsFormsApp1\Properties\Resources.Designer.cs
     文件        6190  2019-02-04 20:15  WindowsFormsApp1\WindowsFormsApp1\Properties\Resources.resx
     文件        1103  2019-02-03 22:06  WindowsFormsApp1\WindowsFormsApp1\Properties\Settings.Designer.cs
     文件         249  2019-02-03 22:06  WindowsFormsApp1\WindowsFormsApp1\Properties\Settings.settings
     目录           0  2019-02-04 20:15  WindowsFormsApp1\WindowsFormsApp1\Resources\
     文件       18810  2019-02-04 20:15  WindowsFormsApp1\WindowsFormsApp1\Resources\1.jpeg
     文件        5178  2019-02-04 20:16  WindowsFormsApp1\WindowsFormsApp1\WindowsFormsApp1.csproj
     文件         479  2019-02-04 14:50  WindowsFormsApp1\WindowsFormsApp1\WindowsFormsApp1.csproj.user
     目录           0  2019-02-04 20:11  WindowsFormsApp1\WindowsFormsApp1\bin\
............此处省略28个文件信息