C#中如何實現數據拖動？(拖動圖片，到TextBox，并顯示)

代碼：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
namespace TestKeyPress
{
 public partial class Form2 : Form
 {
 public Form2()
 {
 InitializeComponent();
 }
 
 private void textBox1_DragEnter(object sender, DragEventArgs e)
 {
 e.Effect = DragDropEffects.Copy;
 }
 private void textBox1_DragDrop(object sender, DragEventArgs e)
 {
 //DataFormats.FileDrop確定你拖動過去的是文件回或者文件夾
 if (e.Data.GetDataPresent(DataFormats.FileDrop))
 {
 string realpath = ((System.Array)e.Data.GetData(DataFormats.FileDrop)).GetValue(0).ToString();
 //從拖動數據里得到路徑
 //MessageBox.Show(realpath);測試路徑
 string p = Path.GetExtension(realpath);
 //MessageBox.Show(p);測試路徑
 if (p == ".jpg")
 {
 //StreamReader sr = new StreamReader(realpath);讀取方式，放棄使用
 Image im = Image.FromFile(realpath);
 int h = im.Height;
 int w = im.Width;
 this.pictureBox1.Height = h;
 this.pictureBox1.Width = w;
 this.pictureBox1.BackgroundImageLayout = ImageLayout.Stretch;
 this.pictureBox1.BackgroundImage = im;
 //將讀取到的圖片放到picturebox里
 //this.pictureBox1.Location = new Point(130 - pictureBox1.Width, 85 - pictureBox1.Height);
 Point pnl = new Point(this.panel1.Width / 2, this.panel1.Height / 2);
 Point pic = new Point();
 pic.X = pnl.X - pictureBox1.Width / 2;
 pic.Y = pnl.Y - pictureBox1.Height / 2;
 this.pictureBox1.Location = pic;
 //上面的代碼是將圖片的中心和panel的中心對齊
 //this.pictureBox1.Location = new Point(85 ,76);
 }
 }
 else
 {
 MessageBox.Show("please select jpg");
 }
 //MessageBox.Show(e.Data.GetType().ToString());
 }
 //放大功能
 private void button1_Click(object sender, EventArgs e)
 {
 Image im = this.pictureBox1.BackgroundImage;
 //im.M
 pictureBox1.Height = (int)(pictureBox1.Height * 1.2);
 pictureBox1.Width = (int)(pictureBox1.Width * 1.2);
 Point pnl = new Point(this.panel1.Width / 2, this.panel1.Height / 2);
 Point pic = new Point();
 pic.X = pnl.X - pictureBox1.Width / 2;
 pic.Y = pnl.Y - pictureBox1.Height / 2;
 this.pictureBox1.Location = pic;
 }
 //縮小功能
 private void button2_Click(object sender, EventArgs e)
 {
 Image im = this.pictureBox1.BackgroundImage;
 //im.M
 pictureBox1.Height = (int)(pictureBox1.Height * 0.85);
 pictureBox1.Width = (int)(pictureBox1.Width * 0.85);
 Point pnl = new Point(this.panel1.Width / 2, this.panel1.Height / 2);
 Point pic = new Point();
 pic.X = pnl.X - pictureBox1.Width / 2;
 pic.Y = pnl.Y - pictureBox1.Height / 2;
 this.pictureBox1.Location = pic;
 }
 private Point start;
 private Point end;
 //下面的函數實現，圖片在panel里可以拖動
 private void panel1_MouseDown(object sender, MouseEventArgs e)
 {
 if (e.Button == MouseButtons.Left)
 {
 start = new Point(e.X, e.Y);
 end = start;
 }
 }

 private void panel1_MouseUp(object sender, MouseEventArgs e)
 {
 end = new Point(e.X, e.Y);
 int picx = this.pictureBox1.Location.X;
 int picy = this.pictureBox1.Location.Y;
 picx += end.X - start.X;
 picy += end.Y - start.Y;
 this.pictureBox1.Location = new Point(picx, picy);
 }
 }
}

數據拖動，主要是在接受數據的地方添加DragEnter和DragDrop事件，必須將接受數據的地方設置為AllowDrop=true，如果在一個窗體內拖動，選擇數據的地方也要設置AllowDrop=true，

轉自：http://blog.csdn.net/luolunz/article/details/7905193