最近做东西需要用到这个，网上找了一下有不少人实现了，比如这位兄弟
http://blog.csdn.net/mngzilin/article/details/5549119
但是有个问题，子窗体无法脱离父窗体独立运动，所以自己重写了一个，初步试了一下，效果挺不错的
可以改进，加入吸附桌面边缘等功能
using System;
using System.Drawing;
using System.Collections.Generic;
using System.Windows.Forms;
namespace TinyBook
{
public enum MagneticLocation
{
Left = 0,
Right = 1,
Top = 2,
Bottom = 3
}
public enum MagneticState
{
Adsorbent, // 吸附
Separation // 分离
}
public class MagneticManager
{
public class ChildFormInfo
{
public Form Child { get; set; }
public MagneticLocation Location { get; set; }
public MagneticState State { get; set; }
public bool CutstomSetLocation { get; set; }
}
public int Step { get; set; }
private Form m_mainForm = null;
private List<ChildFormInfo> m_childs= new List<ChildFormInfo>();
public MagneticManager(Form form)
{
m_mainForm = form;
form.LocationChanged += MainForm_LocationChanged;
form.SizeChanged += MainForm_SizeChanged;
form.FormClosed += MainForm_FormClosed;
Step = 20;
}
public void addChild(Form childForm, MagneticLocation loc)
{
foreach (ChildFormInfo info in m_childs)
{
if (info.Child == childForm)
{
return;
}
}
ChildFormInfo childInfo = new ChildFormInfo();
childInfo.Child = childForm;
childInfo.Location = loc;
childInfo.State = MagneticState.Adsorbent;
childInfo.CutstomSetLocation = false;
childForm.LocationChanged += ChildForm_LocationChanged;
childForm.SizeChanged += ChildForm_SizeChanged;
childForm.FormClosed += ChildForm_FormClosed;
m_childs.Add(childInfo);
adsorbentChild(childInfo);
}
private ChildFormInfo getInfo(Form form)
{
if (form == null)
{
return null;
}
foreach (ChildFormInfo info in m_childs)
{
if (info.Child == form)
{
return info;
}
}
return null;
}
private Point getLocation(ChildFormInfo info)
{
Point pos = Point.Empty;
switch (info.Location)
{
case MagneticLocation.Left:
pos = new Point(m_mainForm.Left - info.Child.Width + 14, m_mainForm.Top);
break;
case MagneticLocation.Right:
pos = new Point(m_mainForm.Right - 14, m_mainForm.Top);
break;
case MagneticLocation.Top:
pos = new Point(m_mainForm.Left, m_mainForm.Top - info.Child.Height);
break;
case MagneticLocation.Bottom:
pos = new Point(m_mainForm.Left, m_mainForm.Bottom);
break;
default:
break;
}
return pos;
}
private void setChildLocation(ChildFormInfo info, Point location)
{
if (info.Child == null)
{
return;
}
info.CutstomSetLocation = true;
info.Child.Location = location;
info.CutstomSetLocation = false;
}
private void setChildLocation(ChildFormInfo info, int x, int y)
{
setChildLocation(info, new Point(x, y));
}
private void resetChildLocation(ChildFormInfo info)
{
if (info.Child == null)
{
return;
}
Point pos = getLocation(info);
setChildLocation(info, pos);
}
private void adsorbentChild(ChildFormInfo info)
{
info.State = MagneticState.Adsorbent;
resetChildLocation(info);
}
private void separationChild(ChildFormInfo info)
{
info.State = MagneticState.Separation;
}
private void MainForm_LocationChanged(object sender, EventArgs e)
{
foreach (ChildFormInfo info in m_childs)
{
if (info.State == MagneticState.Adsorbent)
{
resetChildLocation(info);
}
}
}
private void MainForm_SizeChanged(object sender, EventArgs e)
{
foreach (ChildFormInfo info in m_childs)
{
if (info.State == MagneticState.Adsorbent)
{
resetChildLocation(info);
}
}
}
private void MainForm_FormClosed(object sender, EventArgs e)
{
}
private void ChildForm_LocationChanged(object sender, EventArgs e)
{
ChildFormInfo info = getInfo(sender as Form);
if (info == null)
{
return;
}
if (info.CutstomSetLocation == true)
{
return;
}
Point location = getLocation(info);
if (info.Child.Left > location.X && info.Location == MagneticLocation.Right)
{
if (info.Child.Left - location.X > Step)
{
separationChild(info);
}
else
{
adsorbentChild(info);
}
}
else if (info.Child.Left < location.X && info.Location == MagneticLocation.Left)
{
if (info.Child.Left - location.X < -Step)
{
separationChild(info);
}
else
{
adsorbentChild(info);
}
}
if (info.Child.Top > location.Y && info.Location == MagneticLocation.Bottom)
{
if (info.Child.Top - location.Y > Step)
{
separationChild(info);
}
else
{
adsorbentChild(info);
}
}
else if (info.Child.Top < location.Y && info.Location == MagneticLocation.Top)
{
if (info.Child.Top - location.Y < -Step)
{
separationChild(info);
}
else
{
adsorbentChild(info);
}
}
}
private void ChildForm_SizeChanged(object sender, EventArgs e)
{
ChildFormInfo info = getInfo(sender as Form);
if (info != null && info.State == MagneticState.Adsorbent)
{
resetChildLocation(info);
}
}
private void ChildForm_FormClosed(object sender, EventArgs e)
{
ChildFormInfo info = getInfo(sender as Form);
if (info != null)
{
m_childs.Remove(info);
}
}
}
}
