设置拖拽事件，获取拖拽内容

设置dragEnter

设置DragDrop

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApp25
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            #region 单独设置
            textBox1.AllowDrop = true;//设置控件AllowDrop的属性
            textBox2.AllowDrop = true;
            textBox1.DragEnter += C_DragEnter;//设置控件的DragEnter效果
            textBox2.DragEnter += C_DragEnter;
            #endregion
            #region 批量设置
            //foreach (Control c in this.Controls)
            //{
            //    if (c is TextBox)
            //    {
            //        c.AllowDrop = true;
            //        c.DragEnter += C_DragEnter;
            //    }
            //}
            #endregion
            textBox1.DragDrop += TextBox1_DragDrop;

        }


        private void TextBox1_DragDrop(object sender, DragEventArgs e)
        {
           string html = GetHtmlContent(e.Data);
            string txt = GetStringContent(e.Data);
        }

        private void C_DragEnter(object sender, DragEventArgs e)
        {
            //设置控件的DragEnter效果
            e.Effect = DragDropEffects.All;
        }
        /// <summary>
        /// 获得网页格式的信息
        /// </summary>
        /// <param name="data"></param>
        /// <returns></returns>
        public static string GetHtmlContent(IDataObject data)
        {
            //先判断数据是否为html格式的数据
            if (data.GetDataPresent(DataFormats.Html))
            {
                return data.GetData(DataFormats.Html).ToString();
            }
            else
                return "";

        }
        /// <summary>
        /// 获得文本内容
        /// </summary>
        /// <param name="data"></param>
        /// <returns></returns>
        public static string GetStringContent(IDataObject data)
        {
            //先判断数据是否为html格式的数据
            if (data.GetDataPresent(DataFormats.StringFormat))
            {
                return data.GetData(DataFormats.StringFormat).ToString();
            }
            else
                return "";
        }



    }
}

截取网页内容的正则

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

namespace WindowsFormsApp25
{
    class RegexObject
    {
        public static Regex reglink = new Regex(@"[a-z]+x3A//[^x27x22x20x0Ax0D]+", RegexOptions.IgnoreCase);
        public static Regex regcont = new Regex(@"x3Cx21x2Dx2DStartFragmentx2Dx2Dx3E(?<cont>(w|W)*?)x3Cx21x2Dx2DEndFragmentx2Dx2Dx3E", RegexOptions.IgnoreCase);
        public static Regex reghtml = new Regex(@"<[^>]*>", RegexOptions.IgnoreCase);
        public static Regex regimg = new Regex(@"<W*img[^>]+srcW*x3D[x27x22W]*(?<img>(w|W)*?)[x27x22x20x3E]", RegexOptions.IgnoreCase);
        public static Regex regsource = new Regex(@"sourceURLx3A(?<source>[^
]*)[
]", RegexOptions.IgnoreCase);
        public static Regex regsup = new Regex(@"x3Csupx3E", RegexOptions.IgnoreCase);
        public static Regex regsub = new Regex(@"x3Csubx3E", RegexOptions.IgnoreCase);
        public static Regex regsupsubend = new Regex(@"x3C/su(b|p)x3E", RegexOptions.IgnoreCase);
        public static Regex regemail = new Regex(@"([a-zA-Z0-9_.-])+@(([a-zA-Z0-9-])+.)+([a-zA-Z0-9]{2,5})+", RegexOptions.IgnoreCase);
        public static Regex regehttp = new Regex(@"((http|https)://)?(www.)?[A-Za-z0-9]+.(com|net|cn|com.cn|com.net|net.cn)", RegexOptions.IgnoreCase);
        public static Regex regdate = new Regex(@"((?<!d)((d{2,4}(.|年|/|-))((((0?[13578]|1[02])(.|月|/|-))((3[01])|([12][0-9])|(0?[1-9])))|(0?2(.|月|/|-)((2[0-8])|(1[0-9])|(0?[1-9])))|(((0?[469]|11)(.|月|/|-))((30)|([12][0-9])|(0?[1-9]))))|((([0-9]{2})((0[48]|[2468][048]|[13579][26])|((0[48]|[2468][048]|[3579][26])00))(.|年|/|-))0?2(.|月|/|-)29))日?(?!d))");
        public static Regex regDomain = new Regex(@"(?<mydomain>(?<Protocol>w+)://(?<Domain>[w.x2D]+))/?S*", RegexOptions.IgnoreCase);
        public static Regex regWWW = new Regex(@"(?<url>http(s)?://([w-]+.)+[w-]+(/[w- ./?%&=]*)?)", RegexOptions.IgnoreCase);

        //((http|https)://)?(www.)?[A-Za-z0-9]+.(com|net|cn|com.cn|com.net|net.cn)
        public static Regex regyear = new Regex(@"d{4}");
        public static string GetWWW(string txt)
        {
            return regWWW.Match(txt).Value;
        }
        public static string GetYear(string txt)
        {
            return regyear.Match(txt).Value;
        }
        public static string Getdomain(string url)
        {
            return regDomain.Match(url).Groups["Domain"].Value;
        }
        /// <summary>
        /// 截取日期
        /// </summary>
        /// <param name="txt"></param>
        /// <returns></returns>
        public static string GetDate(string txt)
        {
            return regdate.Match(txt).Value.ToString();
        }
        /// <summary>
        /// 只获得如https://www.baidu.com的部分
        /// </summary>
        /// <param name="txt"></param>
        /// <returns></returns>
        public static string GetHttp(string txt)
        {
            return regehttp.Match(txt).Value.ToString();
        }


        /// <summary>
        /// 获取当前拖拽的内容（拖拽文本）
        /// </summary>
        /// <param name="text"></param>
        /// <returns></returns>
        public static string GetText(string text)
        {
            string cont = regcont.Match(text).Groups["cont"].Value;
            string r = reghtml.Replace(cont, "").Trim();
            return r;
        }
        /// <summary>
        /// 获得链接字段的网址（将要打开的网页）
        /// </summary>
        /// <param name="text"></param>
        /// <returns></returns>
        public static string GetLink(string text)
        {
            string cont = regcont.Match(text).Groups["cont"].Value;
            string r = reglink.Match(cont).Value;
            return r;
        }
        /// <summary>
        /// 获得链接字段的当前网址（现在的网址）
        /// </summary>
        /// <param name="text"></param>
        /// <returns></returns>
        public static string GetRefPage(string text)
        {
            return regsource.Match(text).Groups["source"].Value.Trim();
        }
        /// <summary>
        /// 获取网址信息（包含version,源网址和当前拖拽链接的网址信息）
        /// </summary>
        /// <param name="text"></param>
        /// <returns></returns>
        public static string ReplaceSubSup(string text)
        {
            text = regsup.Replace(text, "(↑");
            text = regsub.Replace(text, "(↓");
            text = regsupsubend.Replace(text, ")").Trim();
            return text;
        }
    }
}