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//[^\x27\x22\x20\x0A\x0D]+", RegexOptions.IgnoreCase);
        public static Regex regcont = new Regex(@"\x3C\x21\x2D\x2DStartFragment\x2D\x2D\x3E(?<cont>(\w|\W)*?)\x3C\x21\x2D\x2DEndFragment\x2D\x2D\x3E", RegexOptions.IgnoreCase);
        public static Regex reghtml = new Regex(@"<[^>]*>", RegexOptions.IgnoreCase);
        public static Regex regimg = new Regex(@"<\W*img[^>]+src\W*\x3D[\x27\x22\W]*(?<img>(\w|\W)*?)[\x27\x22\x20\x3E]", RegexOptions.IgnoreCase);
        public static Regex regsource = new Regex(@"sourceURL\x3A(?<source>[^\r\n]*)[\r\n]", RegexOptions.IgnoreCase);
        public static Regex regsup = new Regex(@"\x3Csup\x3E", RegexOptions.IgnoreCase);
        public static Regex regsub = new Regex(@"\x3Csub\x3E", 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;
        }
    }
}