c# winform 一个可以用鼠标改变控件位置和大小的类,调用即可

using System;
using System.Collections.Generic;
using System.Text;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Windows.Forms;

namespace AllTest
{
class BarcodeControl
{
#region private

private const int MIN_SIZE = 10; //对控件缩放的最小值
private const int BOX_SIZE = 7;  //调整大小触模柄方框大小

public bool _IsCtrlKey = false;
private TextBox _textbox;
private Control _MControl = null;
private bool _IsMouseDown = false;
private Point _oPointClicked;
private Color BOX_COLOR = Color.White;
private Label[] _lbl = new Label[8];
private int _startl, _startt, _startw, _starth;
private bool _dragging;
private Cursor[] _arrArrow = new Cursor[] {Cursors.SizeNWSE, Cursors.SizeNS,
Cursors.SizeNESW, Cursors.SizeWE, Cursors.SizeNWSE, Cursors.SizeNS,
Cursors.SizeNESW, Cursors.SizeWE};

#endregion

#region 构造函数

/// <summary>
/// 构造控件拖动对象
/// </summary>
/// <param name="moveControl">需要拖动的控件 </param>
public BarcodeControl(Control moveControl)
{
//
// TODO: 在此处添加构造函数逻辑
//
_MControl = moveControl;
_MControl.MouseDown += new MouseEventHandler(this.Control_MouseDown);
_MControl.MouseUp += new MouseEventHandler(this.Control_MouseUp);
_MControl.MouseMove += new MouseEventHandler(this.Control_MouseMove);
_MControl.Click += new System.EventHandler(this.Control_Click);

//构造8个调整大小触模柄
for (int i = 0; i < 8; i++)
{
_lbl[i] = new Label();
_lbl[i].TabIndex = i;
_lbl[i].FlatStyle = 0;
_lbl[i].BorderStyle = BorderStyle.FixedSingle;
_lbl[i].BackColor = BOX_COLOR;
_lbl[i].Cursor = _arrArrow[i];
_lbl[i].Text = "";
_lbl[i].BringToFront();
_lbl[i].MouseDown += new MouseEventHandler(this.handle_MouseDown);
_lbl[i].MouseMove += new MouseEventHandler(this.handle_MouseMove);
_lbl[i].MouseUp += new MouseEventHandler(this.handle_MouseUp);
}

CreateTextBox();
Create();

//Control_Click((object)sender, (System.EventArgs)e);
}

#endregion

#region 需拖动控件键盘事件

private void textBox_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e)
{
if (e.KeyValue == 37 || e.KeyValue == 38 || e.KeyValue == 39 || e.KeyValue == 40)
{
if (e.KeyValue == 37)
_MControl.Left -= 1;
if (e.KeyValue == 38)
_MControl.Top -= 1;
if (e.KeyValue == 39)
_MControl.Left += 1;
if (e.KeyValue == 40)
_MControl.Top += 1;
MoveHandles();
ControlLocality();
_MControl.Visible = true;
}

if (e.KeyValue == 46)
{
for (int i = 0; i < 8; i++)
{
_MControl.Parent.Controls.Remove(_lbl[i]);
}
_MControl.Parent.Controls.Remove(_MControl);
_textbox.Parent.Controls.Remove(_textbox);
}

if (e.KeyValue == 17)
{
_IsCtrlKey = true;
//MessageBox.Show("a");
}
}

#endregion

#region 需拖动控件鼠标事件

private void Control_Click(object sender, System.EventArgs e)
{
_textbox.Focus();
_MControl = (sender as Control);
MoveHandles();

if (_IsCtrlKey == false)
{
for (int i = 0; i < _MControl.Parent.Controls.Count; i++)
{
if (_MControl.Parent.Controls[i].Text.Trim().Length == 0 && _MControl.Parent.Controls[i] is Label)
{
_MControl.Parent.Controls[i].Visible = false;
}
}
}
}
private void Control_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{
_IsMouseDown = true;
_oPointClicked = new Point(e.X, e.Y);
for (int i = 0; i < 8; i++)
{
_MControl.Parent.Controls.Add(_lbl[i]);
_lbl[i].BringToFront();
}
HideHandles();
}

private void Control_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e)
{
_IsMouseDown = false;
MoveHandles();
ShowHandles();
_MControl.Visible = true;
}

private void Control_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
{
if (_IsMouseDown)
{
int l = _MControl.Left + (e.X - _oPointClicked.X);
int t = _MControl.Top + (e.Y - _oPointClicked.Y);
int w = _MControl.Width;
int h = _MControl.Height;
l = (l < 0) ? 0 : ((l + w > _MControl.Parent.ClientRectangle.Width) ?
_MControl.Parent.ClientRectangle.Width - w : l);
t = (t < 0) ? 0 : ((t + h > _MControl.Parent.ClientRectangle.Height) ?
_MControl.Parent.ClientRectangle.Height - h : t);
_MControl.Left = l;
_MControl.Top = t;
ControlLocality();
}
//_MControl.Cursor=Cursors.SizeAll;
}

#endregion
#region 调整大小触模柄鼠标事件

private void handle_MouseDown(object sender, MouseEventArgs e)
{
_dragging = true;
_startl = _MControl.Left;
_startt = _MControl.Top;
_startw = _MControl.Width;
_starth = _MControl.Height;
HideHandles();
}
// 通过触模柄调整控件大小
//    0  1  2
//  7      3
//  6  5  4
private void handle_MouseMove(object sender, MouseEventArgs e)
{
int l = _MControl.Left;
int w = _MControl.Width;
int t = _MControl.Top;
int h = _MControl.Height;
if (_dragging)
{
switch (((Label)sender).TabIndex)
{
//l算法：控件左边X坐标 ＋ 鼠标在触模柄X坐标 < 控件左边X坐标 ＋ 父控件宽度 - 控件大小 ？控件左边X坐标 ＋ 鼠标在触模柄X坐标 ：控件左边X坐标 ＋ 父控件宽度 - 控件大小
//t算法：
//w算法：
//h算法：
case 0: // _dragging top-left sizing box
l = _startl + e.X < _startl + _startw - MIN_SIZE ? _startl + e.X : _startl + _startw - MIN_SIZE;
t = _startt + e.Y < _startt + _starth - MIN_SIZE ? _startt + e.Y : _startt + _starth - MIN_SIZE;
w = _startl + _startw - _MControl.Left;
h = _startt + _starth - _MControl.Top;
break;
case 1: // _dragging top-center sizing box
t = _startt + e.Y < _startt + _starth - MIN_SIZE ? _startt + e.Y : _startt + _starth - MIN_SIZE;
h = _startt + _starth - _MControl.Top;
break;
case 2: // _dragging top-right sizing box
w = _startw + e.X > MIN_SIZE ? _startw + e.X : MIN_SIZE;
t = _startt + e.Y < _startt + _starth - MIN_SIZE ? _startt + e.Y : _startt + _starth - MIN_SIZE;
h = _startt + _starth - _MControl.Top;
break;
case 3: // _dragging right-middle sizing box
w = _startw + e.X > MIN_SIZE ? _startw + e.X : MIN_SIZE;
break;
case 4: // _dragging right-bottom sizing box
w = _startw + e.X > MIN_SIZE ? _startw + e.X : MIN_SIZE;
h = _starth + e.Y > MIN_SIZE ? _starth + e.Y : MIN_SIZE;
break;
case 5: // _dragging center-bottom sizing box
h = _starth + e.Y > MIN_SIZE ? _starth + e.Y : MIN_SIZE;
break;
case 6: // _dragging left-bottom sizing box
l = _startl + e.X < _startl + _startw - MIN_SIZE ? _startl + e.X : _startl + _startw - MIN_SIZE;
w = _startl + _startw - _MControl.Left;
h = _starth + e.Y > MIN_SIZE ? _starth + e.Y : MIN_SIZE;
break;
case 7: // _dragging left-middle sizing box
l = _startl + e.X < _startl + _startw - MIN_SIZE ? _startl + e.X : _startl + _startw - MIN_SIZE;
w = _startl + _startw - _MControl.Left;
break;
}
l = (l < 0) ? 0 : l;
t = (t < 0) ? 0 : t;
_MControl.SetBounds(l, t, w, h);
}
}

private void handle_MouseUp(object sender, MouseEventArgs e)
{
_dragging = false;
MoveHandles();
ShowHandles();
}

#endregion

#region private方法

private void Create()
{
//_IsMouseDown = true;
//_oPointClicked = new Point(e.X,e.Y);
for (int i = 0; i < 8; i++)
{
_MControl.Parent.Controls.Add(_lbl[i]);
_lbl[i].BringToFront();
}
HideHandles();
}

private void CreateTextBox()
{
_textbox = new TextBox();
_textbox.CreateControl();
_textbox.Parent = _MControl.Parent;
_textbox.Width = 0;
_textbox.Height = 0;
_textbox.TabStop = true;
_textbox.KeyDown += new System.Windows.Forms.KeyEventHandler(textBox_KeyDown);
}

private void ControlLocality()
{
if (_MControl.Location.X < 0)
{
_MControl.Visible = false;
_MControl.Left = 0;
}
if (_MControl.Location.Y < 0)
{
_MControl.Visible = false;
_MControl.Top = 0;
}
if (_MControl.Location.X + _MControl.Width > _MControl.Parent.Width)
{
_MControl.Visible = false;
_MControl.Left = _MControl.Parent.Width - _MControl.Width;
}
if (_MControl.Location.Y + _MControl.Height > _MControl.Parent.Height)
{
_MControl.Visible = false;
_MControl.Top = _MControl.Parent.Height - _MControl.Height;
}
}

private void HideHandles()
{
for (int i = 0; i < 8; i++)
{
_lbl[i].Visible = false;
}
}

private void MoveHandles()
{
int sX = _MControl.Left - BOX_SIZE;
int sY = _MControl.Top - BOX_SIZE;
int sW = _MControl.Width + BOX_SIZE;
int sH = _MControl.Height + BOX_SIZE;
int hB = BOX_SIZE / 2;
int[] arrPosX = new int[] {sX+hB, sX + sW / 2, sX + sW-hB, sX + sW-hB,
sX + sW-hB, sX + sW / 2, sX+hB, sX+hB};
int[] arrPosY = new int[] {sY+hB, sY+hB, sY+hB, sY + sH / 2, sY + sH-hB,
sY + sH-hB, sY + sH-hB, sY + sH / 2};
for (int i = 0; i < 8; i++)
{
_lbl[i].SetBounds(arrPosX[i], arrPosY[i], BOX_SIZE, BOX_SIZE);
}
}

private void ShowHandles()
{
if (_MControl != null)
{
for (int i = 0; i < 8; i++)
{
_lbl[i].Visible = true;
}
}
}

#endregion
}
}