C# Rubber Band Selection Tool for PictureBox Control
This code implements a rubber band selection tool, which allows the user to select an area on a PictureBox control by dragging the mouse cursor. The selected area is represented by a' rectangle with resize pins at the corners and center. This tool can be used in various applications, such as image editing software, where users need to select specific portions of an image.
Code Implementation
using System.Drawing;
using System.Windows.Forms;
namespace CirecleCCS
{
class CcsGo
{
public int ResizePinSize = 6; // 圆的直径
int HalfRPR
{
get { return ResizePinSize / 2; } //半径
}
private static Pen SelectRectPen, ResizePinPen;
private float[] SelectRectDashPattern;
private static Rectangle SelectRect;
private static Rectangle ResizePin1, ResizePin2, ResizePin3, ResizePin4, ResizePin5, ResizePin6, ResizePin7, ResizePin8;
private static Rectangle rect;
private static int ActivationPinPosition;
//selectrect的x,y,x1,y1
private static int SelectX0, SelectY0, SelectX1, SelectY1;
//8个角+点空白处+点中间
private const int hitNothing = -1;
private const int hitTopLeft = 0;
private const int hitTopRight = 1;
private const int hitBottomRight = 2;
private const int hitBottomLeft = 3;
private const int hitTop = 4;
private const int hitRight = 5;
private const int hitBottom = 6;
private const int hitLeft = 7;
private const int hitMiddle = 8;
private void HideResizePin() //隐藏ResizePin
{
ResizePin1.Width = 0; ResizePin1.Height = 0;
ResizePin2.Width = 0; ResizePin2.Height = 0;
ResizePin3.Width = 0; ResizePin3.Height = 0;
ResizePin4.Width = 0; ResizePin4.Height = 0;
ResizePin5.Width = 0; ResizePin5.Height = 0;
ResizePin6.Width = 0; ResizePin6.Height = 0;
ResizePin7.Width = 0; ResizePin7.Height = 0;
ResizePin8.Width = 0; ResizePin8.Height = 0;
}
void SetResizePinVal() //实时显示ResizePin
{
ResizePin1.X = X - HalfRPR;
ResizePin1.Y = Y - HalfRPR;
ResizePin2.X = X + Width / 2 - HalfRPR;
ResizePin2.Y = Y - HalfRPR;
ResizePin3.X = X + Width - HalfRPR;
ResizePin3.Y = Y - HalfRPR;
ResizePin4.X = X + Width - HalfRPR;
ResizePin4.Y = Y + Height / 2 - HalfRPR;
ResizePin5.X = X + Width - HalfRPR;
ResizePin5.Y = Y + Height - HalfRPR;
ResizePin6.X = X + Width / 2 - HalfRPR;
ResizePin6.Y = Y + Height - HalfRPR;
ResizePin7.X = X - HalfRPR;
ResizePin7.Y = Y + Height - HalfRPR;
ResizePin8.X = X - HalfRPR;
ResizePin8.Y = Y + Height / 2 - HalfRPR;
}
private void ShowResizePin() //显示ResizePin
{
ResizePin1.X = SelectRect.X - HalfRPR;
ResizePin1.Y = SelectRect.Y - HalfRPR;
ResizePin2.X = SelectRect.X + SelectRect.Width / 2 - HalfRPR;
ResizePin2.Y = SelectRect.Y - HalfRPR;
ResizePin3.X = SelectRect.X + SelectRect.Width - HalfRPR;
ResizePin3.Y = SelectRect.Y - HalfRPR;
ResizePin4.X = SelectRect.X + SelectRect.Width - HalfRPR;
ResizePin4.Y = SelectRect.Y + SelectRect.Height / 2 - HalfRPR;
ResizePin5.X = SelectRect.X + SelectRect.Width - HalfRPR;
ResizePin5.Y = SelectRect.Y + SelectRect.Height - HalfRPR;
ResizePin6.X = SelectRect.X + SelectRect.Width / 2 - HalfRPR;
ResizePin6.Y = SelectRect.Y + SelectRect.Height - HalfRPR;
ResizePin7.X = SelectRect.X - HalfRPR;
ResizePin7.Y = SelectRect.Y + SelectRect.Height - HalfRPR;
ResizePin8.X = SelectRect.X - HalfRPR;
ResizePin8.Y = SelectRect.Y + SelectRect.Height / 2 - HalfRPR;
ResizePin1.Width = ResizePinSize; ResizePin1.Height = ResizePinSize;
ResizePin2.Width = ResizePinSize; ResizePin2.Height = ResizePinSize;
ResizePin3.Width = ResizePinSize; ResizePin3.Height = ResizePinSize;
ResizePin4.Width = ResizePinSize; ResizePin4.Height = ResizePinSize;
ResizePin5.Width = ResizePinSize; ResizePin5.Height = ResizePinSize;
ResizePin6.Width = ResizePinSize; ResizePin6.Height = ResizePinSize;
ResizePin7.Width = ResizePinSize; ResizePin7.Height = ResizePinSize;
ResizePin8.Width = ResizePinSize; ResizePin8.Height = ResizePinSize;
}
void FillResizePins(PaintEventArgs e) // 填充ResizePinRect颜色
{
e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
e.Graphics.FillEllipse(Brushes.SteelBlue,ResizePin1);
e.Graphics.FillEllipse(Brushes.SteelBlue, ResizePin2);
e.Graphics.FillEllipse(Brushes.SteelBlue, ResizePin3);
e.Graphics.FillEllipse(Brushes.SteelBlue, ResizePin4);
e.Graphics.FillEllipse(Brushes.SteelBlue, ResizePin5);
e.Graphics.FillEllipse(Brushes.SteelBlue, ResizePin6);
e.Graphics.FillEllipse(Brushes.SteelBlue, ResizePin7);
e.Graphics.FillEllipse(Brushes.SteelBlue, ResizePin8);
}
void DrawResizePin(Graphics g) //绘制ResizePin
{
g.DrawEllipse(ResizePinPen,ResizePin1);
g.DrawEllipse(ResizePinPen,ResizePin2);
g.DrawEllipse(ResizePinPen,ResizePin3);
g.DrawEllipse(ResizePinPen,ResizePin4);
g.DrawEllipse(ResizePinPen,ResizePin5);
g.DrawEllipse(ResizePinPen,ResizePin6);
g.DrawEllipse(ResizePinPen,ResizePin7);
g.DrawEllipse(ResizePinPen,ResizePin8);
}
bool InELP(MouseEventArgs e,Point ElpCenter) //是否在ResizePin圆内
{
int elpX = ElpCenter.X;
int elpY = ElpCenter.Y;
return !((elpX - e.X) * (elpX - e.X) + (elpY - e.Y) * (elpY - e.Y) >= HalfRPR * HalfRPR);
}
private int HitTest(MouseEventArgs e) //测试哪个ResizePin被选中
{
if(InELP(e,new Point(ResizePin1.X + HalfRPR,ResizePin1.Y + HalfRPR)))
return hitTopLeft;
else if (InELP(e,new Point(ResizePin2.X + HalfRPR, ResizePin2.Y + HalfRPR)))
return hitTop;
else if (InELP(e,new Point(ResizePin3.X + HalfRPR,ResizePin3.Y + HalfRPR)))
return hitTopRight;
else if (InELP(e, new Point(ResizePin4.X + HalfRPR, ResizePin4.Y + HalfRPR)))
return hitRight;
else if (InELP(e, new Point(ResizePin5.X + HalfRPR, ResizePin5.Y + HalfRPR)))
return hitBottomRight;
else if (InELP(e, new Point(ResizePin6.X + HalfRPR, ResizePin6.Y + HalfRPR)))
return hitBottom;
else if (InELP(e, new Point(ResizePin7.X + HalfRPR, ResizePin7.Y + HalfRPR)))
return hitBottomLeft;
else if (InELP(e, new Point(ResizePin8.X + HalfRPR, ResizePin8.Y + HalfRPR)))
return hitLeft;
else if (e.X >= SelectRect.X + ResizePinSize && e.X <= SelectRect.X + SelectRect.Width - ResizePinSize
&& e.Y >= SelectRect.Y + ResizePinSize && e.Y <= SelectRect.Y + SelectRect.Height - ResizePinSize)
return hitMiddle;
else
return hitNothing;
}
public void Create() //初始化参数
{
ResizePinPen = new Pen(Color.SteelBlue, 2);
SelectRectDashPattern = new float[] {3,2,1};
SelectRectPen = new Pen(Color.SteelBlue, 2.0f);
//{ // DashPattern = SelectRectDashPattern, // };
SelectRect = new Rectangle();
ResizePin1 = new Rectangle();
ResizePin2 = new Rectangle();
ResizePin3 = new Rectangle();
ResizePin4 = new Rectangle();
ResizePin5 = new Rectangle();
ResizePin6 = new Rectangle();
ResizePin7 = new Rectangle();
ResizePin8 = new Rectangle();
rect = new Rectangle();
ActivationPinPosition = hitNothing;
}
void StayInBoxR(PictureBox R) //待在box里面别出去
{
if (SelectRect.X < 0)
SelectRect.X = 0;
if (SelectRect.Y < 0)
SelectRect.Y = 0;
if (SelectRect.X + SelectRect.Width > R.Width)
SelectRect.X = R.Width - SelectRect.Width;
if (SelectRect.Y + SelectRect.Height > R.Height)
SelectRect.Y = R.Height - SelectRect.Height;
}
public void Destroy() //释放资源
{
SelectRectPen.Dispose();
ResizePinPen.Dispose();
}
public void StartPoint(PictureBox p, MouseEventArgs e) //鼠标左键按下后
{
if (e.Button == MouseButtons.Left)
{
p.Invalidate(null, true);
switch (HitTest(e))
{
case hitTopLeft:
ActivationPinPosition = hitTopLeft;
SelectX1 = SelectRect.X + SelectRect.Width;
SelectY1 = SelectRect.Y + SelectRect.Height;
break;
case hitTop:
ActivationPinPosition = hitTop;
SelectX1 = SelectRect.Width + SelectRect.X;
SelectY1 = SelectRect.Height + SelectY0;
break;
case hitTopRight:
ActivationPinPosition = hitTopRight;
SelectY1 = SelectRect.Y + SelectRect.Height;
break;
case hitRight:
ActivationPinPosition = hitRight;
SelectY1 = SelectRect.Y + SelectRect.Height;
break;
case hitBottomRight:
ActivationPinPosition = hitBottomRight;
break;
case hitBottom:
ActivationPinPosition = hitBottom;
SelectX1 = SelectRect.X + SelectRect.Width;
break;
case hitBottomLeft:
ActivationPinPosition = hitBottomLeft;
SelectX1 = SelectRect.X + SelectRect.Width;
break;
case hitLeft:
ActivationPinPosition = hitLeft;
SelectX1 = SelectRect.X + SelectRect.Width;
SelectY1 = SelectRect.Y + SelectRect.Height;
break;
case hitMiddle:
ActivationPinPosition = hitMiddle;
SelectX0 = e.X - SelectRect.X;
SelectY0 = e.Y - SelectRect.Y;
SelectX1 = SelectRect.X + SelectRect.Width - e.X;
SelectY1 = SelectRect.Y + SelectRect.Height - e.Y;
break;
case hitNothing:
ActivationPinPosition = hitNothing;
SelectRect.Width = 0;
SelectRect.Height = 0;
SelectX0 = e.X;
SelectY0 = e.Y;
HideResizePin();
break;
}
}
}
public void TrackRubberBand(PictureBox p, MouseEventArgs e, bool Iskeep = false) //鼠标左键拖动时动态显示矩形框
{
switch (HitTest(e))
{
case hitTopLeft:
p.Cursor = Cursors.SizeNWSE;
break;
case hitTop:
p.Cursor = Cursors.SizeNS;
break;
case hitTopRight:
p.Cursor = Cursors.SizeNESW;
break;
case hitRight:
p.Cursor = Cursors.SizeWE;
break;
case hitBottomRight:
p.Cursor = Cursors.SizeNWSE;
break;
case hitBottom:
p.Cursor = Cursors.SizeNS;
break;
case hitBottomLeft:
p.Cursor = Cursors.SizeNESW;
break;
case hitLeft:
p.Cursor = Cursors.SizeWE;
break;
case hitMiddle:
p.Cursor = Cursors.SizeAll;
break;
case hitNothing:
p.Cursor = Cursors.Default;
break;
}
if (e.Button == MouseButtons.Left)
{
int TLX = e.X;
int TLY = e.Y;
if (e.X < 0)
TLX = 0;
else if (e.X > p.Width)
TLX = p.Width;
if (e.Y < 0)
TLY = 0;
else if (e.Y > p.Height)
TLY = p.Height;
if (!Iskeep)
{
p.Invalidate(InvalidateRectangle(), false);
}
switch (ActivationPinPosition)
{
case hitTopLeft:
GenerateRectangle(ref SelectRect, TLX, TLY, SelectX1, SelectY1);
StayInBoxR(p);
SetResizePinVal();
break;
case hitTop:
GenerateRectangle(ref SelectRect, SelectX0, TLY, SelectX1, SelectY1);
StayInBoxR(p);
SetResizePinVal();
break;
case hitTopRight:
GenerateRectangle(ref SelectRect, SelectX0, TLY, TLX, SelectY1);
StayInBoxR(p);
SetResizePinVal();
break;
case hitRight:
GenerateRectangle(ref SelectRect, SelectX0, SelectY0, TLX, SelectY1);
StayInBoxR(p);
SetResizePinVal();
break;
case hitBottomRight:
GenerateRectangle(ref SelectRect, SelectX0, SelectY0, TLX, TLY);
StayInBoxR(p);
SetResizePinVal();
break;
case hitBottom:
GenerateRectangle(ref SelectRect, SelectX0, SelectY0, SelectX1, TLY);
StayInBoxR(p);
SetResizePinVal();
break;
case hitBottomLeft:
GenerateRectangle(ref SelectRect, TLX, SelectY0, SelectX1, TLY);
StayInBoxR(p);
SetResizePinVal();
break;
case hitLeft:
GenerateRectangle(ref SelectRect, TLX, SelectY0, SelectX1, SelectY1);
StayInBoxR(p);
SetResizePinVal();
break;
case hitMiddle:
GenerateRectangle(ref SelectRect, e.X - SelectX0, e.Y - SelectY0, e.X + SelectX1, e.Y + SelectY1);
StayInBoxR(p);
SetResizePinVal();
break;
case hitNothing:
GenerateRectangle(ref SelectRect, SelectX0, SelectY0, TLX, TLY);
StayInBoxR(p);
SetResizePinVal();
break;
}
}
}
public void EndPoint(PictureBox frm, MouseEventArgs e) //鼠标左键松开后
{
if (e.Button == MouseButtons.Left)
{
frm.Invalidate(null, true);
SelectX0 = SelectRect.X;
SelectY0 = SelectRect.Y;
if(HitTest(e) != hitNothing && X > ResizePinSize && Y > ResizePinSize)
ShowResizePin();
}
}
public void DrawRubberBand(PictureBox frm, PaintEventArgs e) //绘制矩形框
{
e.Graphics.DrawRectangle(SelectRectPen, SelectRect);
FillResizePins(e);
DrawResizePin(e.Graphics);
}
private void GenerateRectangle(ref Rectangle TempRectangle, int X0, int Y0, int X1, int Y1) //根据指定两点坐标生成矩形框
{
if (X0 < X1)
{
TempRectangle.X = X0;
TempRectangle.Width = X1 - X0;
}
else
{
TempRectangle.X = X1;
TempRectangle.Width = X0 - X1;
}
if (Y0 < Y1)
{
TempRectangle.Y = Y0;
TempRectangle.Height = Y1 - Y0;
}
else
{
TempRectangle.Y = Y1;
TempRectangle.Height = Y0 - Y1;
}
}
//RubberBand的属性
public int X
{
get
{
return SelectRect.X;
}
}
public int Y
{
get
{
return SelectRect.Y;
}
}
public int Width
{
get
{
return SelectRect.Width;
}
}
public int Height
{
get
{
return SelectRect.Height;
}
}
public Pen RectView { get => RectView; set => RectView = value; }
public Rectangle InvalidateRectangle() //获得无效区域，用来刷新时防止闪烁
{
rect.X = SelectRect.X - 8;
rect.Y = SelectRect.Y - 8;
rect.Width = SelectRect.Width + 16;
rect.Height = SelectRect.Height + 16;
return rect;
}
public void SetRect(int ex, int ey, int ew, int eh) // set ccs框的位置以及尺寸
{
GenerateRectangle(ref SelectRect, ex, ey, ex + ew, ey + eh);
}
public void HideCCS() //隐藏起来
{
HideResizePin();
SetRect(0, 0, 0, 0);
}
}
}
Explanation
- Initialization: The code initializes pens for drawing the selection rectangle and resize pins, and creates rectangles to represent the selection area and resize pins.
- Hit Testing: The
HitTestfunction determines which resize pin or the middle area is clicked based on mouse coordinates. - Rubber Band Drawing: The
TrackRubberBandfunction dynamically draws the selection rectangle as the mouse is dragged. It also handles cursor changes based on the hit test result. - Resize Pins: The
ShowResizePin,HideResizePin, andSetResizePinValfunctions manage the visibility and positions of the resize pins. - Invalidation: The
InvalidateRectanglefunction returns the invalidated area to prevent flickering during redrawing. - SetRect: The
SetRectfunction allows setting the position and size of the selection rectangle directly. - HideCCS: The
HideCCSfunction hides the selection rectangle and resize pins.
Usage
To use the rubber band selection tool, you can create an instance of the CcsGo class and call its methods within the relevant mouse events of your PictureBox control. For example:
private CcsGo ccsGo = new CcsGo();
private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
ccsGo.StartPoint(pictureBox1, e);
}
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
ccsGo.TrackRubberBand(pictureBox1, e);
}
private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
ccsGo.EndPoint(pictureBox1, e);
}
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
ccsGo.DrawRubberBand(pictureBox1, e);
}
This code will allow the user to select an area on the PictureBox by dragging the mouse and resize it by dragging the resize pins.
原文地址: https://www.cveoy.top/t/topic/ndzh 著作权归作者所有。请勿转载和采集!