【转载】窗体之间的控件拖动

原作者：

C# code

public class MovingObject
    {
protected Control control;

public MovingObject(Control ctrl)
        {
            control = ctrl;
        }

public Control MovingControl
        {
get { return control; }
        }
    }

再封装一个Helper类

C# code

public class User32
    {
        [DllImport("User32.dll")]
public static extern int GetWindowRect(IntPtr handle, ref Rectangle rect);
    }

OK, 现在随便写一个Form2作为Test用的一个子窗体, 上面只摆一个ListBox控件

C# code

public partial class Form2 : Form
    {
public Form2()
        {
            InitializeComponent();
            AllowDrop = true;

            listBox1.MouseDown += new MouseEventHandler(listBox1_MouseDown);
            DragEnter += new DragEventHandler(Form2_DragEnter);
            DragDrop += new DragEventHandler(Form2_DragDrop);
        }

void Form2_DragDrop(object sender, DragEventArgs e)
        {
if (e.Data.GetDataPresent(typeof(MovingObject)))
            {
                MovingObject movingObj = e.Data.GetData(typeof(MovingObject)) as MovingObject;
if (movingObj != null)
                {
                    Rectangle rect = Rectangle.Empty;
                    User32.GetWindowRect(Handle, ref rect);
                    movingObj.MovingControl.Location = new Point(e.X - rect.Location.X - 6, e.Y - rect.Location.Y - 34);
                    Controls.Add(movingObj.MovingControl);
                }
            }
        }

void Form2_DragEnter(object sender, DragEventArgs e)
        {
if (e.Data.GetDataPresent(typeof(MovingObject)))
                e.Effect = DragDropEffects.Copy;
        }

void listBox1_MouseDown(object sender, MouseEventArgs e)
        {
            DoDragDrop(new MovingObject(listBox1), DragDropEffects.Copy);
        }
    }

同样, 写一个Form3的子窗体, 上面只有一个Button控件

C# code

public partial class Form3 : Form
    {
public Form3()
        {
            InitializeComponent();
            AllowDrop = true;

            button1.MouseDown += new MouseEventHandler(button1_MouseDown);
            DragEnter += new DragEventHandler(Form3_DragEnter);
            DragDrop += new DragEventHandler(Form3_DragDrop);
        }

void Form3_DragDrop(object sender, DragEventArgs e)
        {
if (e.Data.GetDataPresent(typeof(MovingObject)))
            {
                MovingObject movingObj = e.Data.GetData(typeof(MovingObject)) as MovingObject;
if (movingObj != null)
                {
                    Rectangle rect = Rectangle.Empty;
                    User32.GetWindowRect(Handle, ref rect);
                    movingObj.MovingControl.Location = new Point(e.X - rect.Location.X - 6, e.Y - rect.Location.Y - 34);
                    Controls.Add(movingObj.MovingControl);
                }
            }
        }

void Form3_DragEnter(object sender, DragEventArgs e)
        {
if (e.Data.GetDataPresent(typeof(MovingObject)))
                e.Effect = DragDropEffects.Copy;
        }

void button1_MouseDown(object sender, MouseEventArgs e)
        {
            DoDragDrop(new MovingObject(button1), DragDropEffects.Copy);
        }
    }

好, 现在再弄个MainForm出来, 就叫做Form1吧, 记得要把Form1的IsMdiContainer设为True哦~

C# code

public partial class Form1 : Form
    {
private Form2 f2;
private Form3 f3;

public Form1()
        {
            InitializeComponent();

            f2 = new Form2();
            f3 = new Form3();

            f2.MdiParent = this;
            f3.MdiParent = this;

            f2.Show();
            f3.Show();
        }
    }

怎么样? 发现button1和listBox1可以在两个窗体间自由的拖动没?