最近要做个winform的东西，要在里面集成一个类似Windows自带画图的标尺功能，还要能在图片上画矩形框。在网上找了好久也没找到写好的控件，无奈自己做了一个。
目前还有些bug，这里先做个分享。（Ps:很少做winform的东西，做的不好，轻喷。另外欢迎指点。）
由于最后要做的东西的背景是黑的，标尺就画成白的了，有需要的自己改吧。。
直接上代码
using Helper; using System; using System.Collections.Generic; using System.Drawing; using System.Windows.Forms; namespace UserCtrl { public partial class RulerControl : UserControl { private double _monitorDPI = 100; /// <summary> /// 用于控制放大倍数 /// </summary> private double _multiple = 1; /// <summary> /// 每多少个像素1格 /// </summary> public double MonitorDPI { get { return _monitorDPI; } set { _monitorDPI = value; } } /// <summary> /// X轴偏移位置 /// </summary> private float offSetX=0; /// <summary> /// Y轴偏移位置 /// </summary> private float offSetY = 0; /// <summary> /// 开始位置X /// </summary> public double XStart { get; set; } /// <summary> /// 开始位置Y /// </summary> public double YStart { get; set; } /// <summary> /// 用户设置的原始图 /// </summary> private Image _initImg = null; /// <summary> /// 图片 /// </summary> public Image Image { get { return Pic.Image; } set { Pic.Image = value; if (_initImg == null&&value!=null) { _initImg = PicHelper.GetNewPic(value, value.Width , value.Height ); } } } private Font font = new Font("宋体", 9); //刻度值显示字体 public RulerControl() { InitializeComponent(); } private void Pic_MouseWheel(object sender, MouseEventArgs e) { if (MouseButtons == MouseButtons.Left) { return; } Image img = Pic.Image; if (img != null) { if (e.Delta >= 0) { if (_multiple * 2 > 4) return; _multiple *= 2; } else { if (Pic.Width < this.Width - 50) return; _multiple *= 0.5; if (Pic.Width <= (this.Width - 50)) { XStart = 0; YStart = 0; } } DrawRect(); AdapterDpi(); ReDrawX(); ReDrawY(); } } private void RulerControl_Paint(object sender, PaintEventArgs e) { P1.Height = 50; P1.Width = this.Width - 50; P2.Height = this.Height - 50; P2.Width = 50; P1.Location = new Point(50, 0); P2.Location = new Point(0, 50); PContainer.Location = new Point(50, 50); } private void RulerControl_Resize(object sender, EventArgs e) { P1.Height = 50; P1.Width = this.Width - 50; P2.Height = this.Height - 50; P2.Width = 50; P1.Location = new Point(50, 0); P2.Location = new Point(0, 50); PContainer.Location = new Point(50, 50); } /// <summary> /// 重画Y轴 /// </summary> private void ReDrawY() { if (P2.BackgroundImage != null) { P2.BackgroundImage.Dispose(); } Bitmap bmpY = new Bitmap(P2.Width, P2.Height); using (Graphics g = Graphics.FromImage(bmpY)) { int originLocation = bmpY.Width - 1; int startY = (int)Math.Ceiling(YStart); offSetY = (float)(MonitorDPI * _multiple * (startY - YStart)); for (int i = startY; i <= Math.Ceiling(P2.Height / (MonitorDPI * _multiple) + YStart); i++) { float y = (float)(MonitorDPI * _multiple * (i - YStart)) + offSetY; if (y >= 0) { PointF start = new PointF(originLocation, y); PointF end = new PointF(originLocation - 3, y); if (i % 5 == 0) { end = new PointF(originLocation - 6, y); } if (i % 10 == 0 && i != 0) { end = new PointF(originLocation - 12, y); g.DrawString((i*MonitorDPI).ToString(), font, Brushes.White, new PointF(originLocation - 30, y - 5)); } g.DrawLine(Pens.White, start, end); } } g.DrawLine(Pens.White, new PointF(originLocation, 0), new PointF(originLocation, bmpY.Height)); P2.BackgroundImage = bmpY; } } /// <summary> /// 重画X轴 /// </summary> private void ReDrawX() { if (P1.BackgroundImage != null) { P1.BackgroundImage.Dispose(); } Bitmap bmpX = new Bitmap(P1.Width, P1.Height); using (Graphics g = Graphics.FromImage(bmpX)) { int originLocation = bmpX.Height - 1; int startX = (int)Math.Ceiling(XStart); offSetX = (float)(MonitorDPI * _multiple * (startX - XStart)); for (int i = startX; i <= Math.Ceiling(P1.Width / (MonitorDPI * _multiple) + XStart); i++) { float x = (float)(MonitorDPI * _multiple * (i - XStart)) + offSetX; if (x >= 0) { PointF start = new PointF(x, originLocation); PointF end = new PointF(x, originLocation - 3); if (i % 5 == 0) { end = new PointF(x, originLocation - 6); } if (i % 10 == 0 && i != 0) { end = new PointF(x, originLocation - 12); g.DrawString((i*MonitorDPI).ToString(), font, Brushes.White, new PointF(x - 5, originLocation - 30)); } g.DrawLine(Pens.White, start, end); } } g.DrawLine(Pens.White, new PointF(0, originLocation), new PointF(bmpX.Width, originLocation)); P1.BackgroundImage = bmpX; } } private void RulerControl_Load(object sender, EventArgs e) { P1.Height = 50; P1.Width = this.Width - 50; P2.Height = this.Height - 50; P2.Width = 50; P1.Location = new Point(50, 0); P2.Location = new Point(0, 50); PContainer.Location = new Point(50, 50); ReDrawX(); ReDrawY(); Pic.MouseWheel += new MouseEventHandler(Pic_MouseWheel); } private void Pic_MouseEnter(object sender, EventArgs e) { Pic.Focus(); } private void PContainer_Scroll(object sender, ScrollEventArgs e) { if (e.ScrollOrientation == ScrollOrientation.HorizontalScroll) { XStart = e.NewValue / (MonitorDPI * _multiple); ReDrawX(); } else if (e.ScrollOrientation == ScrollOrientation.VerticalScroll) { YStart = e.NewValue / (MonitorDPI * _multiple); ReDrawY(); } } #region 画图片选定区域 bool MouseIsDown = false; Rectangle MouseRect = Rectangle.Empty; private void Pic_MouseDown(object sender, MouseEventArgs e) { MouseIsDown = true; MouseRect = new Rectangle(e.X, e.Y, 0, 0); Rectangle rec = new Rectangle(0, 0, Math.Min(PContainer.ClientRectangle.Width, Pic.ClientRectangle.Width), Math.Min(PContainer.ClientRectangle.Height, Pic.ClientRectangle.Height)); Cursor.Clip = PContainer.RectangleToScreen(rec); } private void Pic_MouseMove(object sender, MouseEventArgs e) { if (MouseIsDown) { MouseRect.Width = e.X - MouseRect.Left; MouseRect.Height = e.Y - MouseRect.Top; if (MouseRect.Width > 0 && MouseRect.Height > 0) { Rectangle rect = Pic.RectangleToScreen(MouseRect); ControlPaint.DrawReversibleFrame(rect, Color.White, FrameStyle.Dashed); } Pic.Refresh(); } } private void Pic_MouseUp(object sender, MouseEventArgs e) { if (MouseIsDown) { MouseRect.Width = e.X - MouseRect.Left; MouseRect.Height = e.Y - MouseRect.Top; using (Graphics g = Graphics.FromImage(Pic.Image)) { g.DrawRectangle(new Pen(Color.Red), MouseRect); } Pic.Refresh(); MouseIsDown = false; if ((int)(MouseRect.Width * _multiple) > 0 && (int)(MouseRect.Height * _multiple) > 0) { list.Add(new Rectangle((int)(MouseRect.X / _multiple), (int)(MouseRect.Y / _multiple), (int)(MouseRect.Width / _multiple), (int)(MouseRect.Height / _multiple) )); } MouseRect = Rectangle.Empty; Cursor.Clip = Rectangle.Empty; } } #endregion public List<Rectangle> list = new List<Rectangle>(); private void Pic_DoubleClick(object sender, EventArgs e) { MouseEventArgs ev = e as MouseEventArgs; List<Rectangle> temp = new List<Rectangle>(); foreach (Rectangle item in list) { if (ev.X > item.X * _multiple && ev.X < item.X * _multiple + item.Width * _multiple && ev.Y > item.Y * _multiple && ev.Y < item.Y * _multiple + item.Height * _multiple) { temp.Add(item); } } foreach (Rectangle item in temp) { list.Remove(item); } DrawRect(); } /// <summary> /// 把list中的框画到图片中 /// </summary> private void DrawRect() { if (Pic.Image != _initImg) Pic.Image.Dispose(); Pic.Image = PicHelper.GetNewPic(_initImg, (int)(_initImg.Width * _multiple), (int)(_initImg.Height * _multiple)); using (Graphics g = Graphics.FromImage(Image)) { foreach (Rectangle item in list) { g.DrawRectangle(new Pen(Color.Red), new Rectangle((int)(item.X * _multiple), (int)(item.Y * _multiple), (int)(item.Width * _multiple), (int)(item.Height * _multiple) )); } } Pic.Refresh(); } private void AdapterDpi() { if (MonitorDPI * _multiple < 10) { MonitorDPI *= 2; } if (MonitorDPI * _multiple > 20) { MonitorDPI /= 2; } } } }
下载链接：http://download.csdn.net/download/p690075426/10142184
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作者：ydp1991
来源：博客园
原文：https://www.cnblogs.com/ydp1991/p/7955382.html