【转载】窗体之间的控件拖动

原作者： LeoMaya

用DoDragDrop可以做到的

首先, 封装一个DragDropObject的Class

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?