Question

我有3层（从here控制“LayerControl”）：图像层，绘图层和选择矩形层。

ImgEditor是一个用于编辑图像的表单（我正在制作屏幕截图，我想为其添加一个图像编辑器）。

图层按以下顺序排序：

l3 - 矩形图层
l2 - 绘图层
l - 图像层

因为l3是顶级控件，我必须在其上使用回调MouseDown，MouseMove和MouseUp，然后在l2（绘图层）上绘制。但是当我想画画的时候，我什么都没得到。或者，如果我将l2作为顶层，我将获得this。

我的代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace SSTool
{
    public partial class ImgEditor : Form
    {
        private Graphics g;
        public Image _i;
        public Brush gb = new SolidBrush(Color.Red);
        public bool md = false;
        public LayerControl l;
        public LayerControl l2;
        public LayerControl l3;
        public Point? _Previous = null;

        public ImgEditor(Image i, Rectangle r)
        {
            //l - main image
            //l2 - drawing layer
            //l3 - rectangle layer
            InitializeComponent();
            l = new LayerControl(i.Size);
            l2 = new LayerControl(i.Size);
            l3 = new LayerControl(i.Size);
            this.Controls.Add(l3);
            this.Controls.Add(l2);
            this.Controls.Add(l);
            l.Dock = DockStyle.Fill;
            l2.Dock = DockStyle.Fill;
            l3.Dock = DockStyle.Fill;
            l2.Image = new Bitmap(i.Size.Width, i.Size.Height);
            l3.MouseDown += new MouseEventHandler(l3_MouseDown);
            l3.MouseMove += new MouseEventHandler(l3_MouseMove);
            l3.MouseUp += new MouseEventHandler(l3_MouseUp);
            _i = i;
            l.Image = _i;
            this.Size = _i.Size;
            g = Graphics.FromImage(l3.Image);
            g.Clear(Color.Transparent);
            Pen p = new Pen(Color.FromArgb(180, 255, 0, 0));
            Brush sb = new SolidBrush(Color.FromArgb(128, 211, 211, 211));
            g.FillRectangle(sb, new Rectangle(0, 0, i.Size.Width, r.Location.Y)); //TOP
            g.FillRectangle(sb, new Rectangle(0, r.Location.Y, r.Location.X, i.Size.Height - r.Location.Y)); //LEFT
            g.FillRectangle(sb, new Rectangle(r.Location.X, r.Location.Y + r.Size.Height + 1, i.Size.Width - r.Location.X, i.Size.Height - r.Location.Y - r.Size.Height - 1)); //BOTTOM
            g.FillRectangle(sb, new Rectangle(r.Location.X + r.Size.Width + 1, r.Location.Y, i.Size.Width - r.Location.X - r.Size.Width - 1, r.Size.Height + 1)); //RIGHT
            g.DrawRectangle(p, r);
            g.Dispose();
        }

        void l3_MouseUp(object sender, MouseEventArgs e)
        {
            _Previous = null;
        }

        void l3_MouseMove(object sender, MouseEventArgs e)
        {
            if (_Previous != null)
            {
                if (l2.Image == null)
                {
                    Bitmap bmp = new Bitmap(l2.Width, l2.Height);
                    using (Graphics g = Graphics.FromImage(bmp))
                    {
                        g.Clear(Color.White);
                    }
                    l2.Image = bmp;
                }
                using (Graphics g = Graphics.FromImage(l2.Image))
                {
                    g.DrawLine(Pens.Black, _Previous.Value, e.Location);
                }
                l2.Invalidate();
                _Previous = e.Location;
            }
        }

        void l3_MouseDown(object sender, MouseEventArgs e)
        {
            _Previous = e.Location;
            l3_MouseMove(sender, e);
        }
    }

    public class LayerControl : UserControl
    {
        private Image image;
        private Graphics graphics;

        public LayerControl(Size s)
        {
            this.Width = s.Width;
            this.Height = s.Height;

            image = new Bitmap(s.Width, s.Height);

            graphics = Graphics.FromImage(image);

            SetStyle(ControlStyles.OptimizedDoubleBuffer |
                    ControlStyles.AllPaintingInWmPaint |
                    ControlStyles.UserPaint, true);
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            var bitMap = new Bitmap(image);

            image = bitMap;

            Graphics g = e.Graphics;
            g.SmoothingMode = SmoothingMode.AntiAlias;
            g.PixelOffsetMode = PixelOffsetMode.HighQuality;
            g.CompositingQuality = CompositingQuality.GammaCorrected;

            float[][] mtxItems = {
            new float[] {1,0,0,0,0},
            new float[] {0,1,0,0,0},
            new float[] {0,0,1,0,0},
            new float[] {0,0,0,1,0},
            new float[] {0,0,0,0,1}};

            ColorMatrix colorMatrix = new ColorMatrix(mtxItems);

            ImageAttributes imgAtb = new ImageAttributes();
            imgAtb.SetColorMatrix(
                colorMatrix,
                ColorMatrixFlag.Default,
                ColorAdjustType.Bitmap);

            g.DrawImage(image,
                        ClientRectangle,
                        0.0f,
                        0.0f,
                        image.Width,
                        image.Height,
                        GraphicsUnit.Pixel,
                        imgAtb);
        }

        protected override void OnPaintBackground(PaintEventArgs e)
        {
            base.OnPaintBackground(e);
            Graphics g = e.Graphics;

            if (Parent != null)
            {
                BackColor = Color.Transparent;
                int index = Parent.Controls.GetChildIndex(this);

                for (int i = Parent.Controls.Count - 1; i > index; i--)
                {
                    Control c = Parent.Controls[i];
                    if (c.Bounds.IntersectsWith(Bounds) && c.Visible)
                    {
                        Bitmap bmp = new Bitmap(c.Width, c.Height, g);
                        c.DrawToBitmap(bmp, c.ClientRectangle);

                        g.TranslateTransform(c.Left - Left, c.Top - Top);
                        g.DrawImageUnscaled(bmp, Point.Empty);
                        g.TranslateTransform(Left - c.Left, Top - c.Top);
                        bmp.Dispose();
                    }
                }
            }
            else
            {
                g.Clear(Parent.BackColor);
                g.FillRectangle(new SolidBrush(Color.FromArgb(255, Color.Transparent)), this.ClientRectangle);
            }
        }

        public Image Image
        {
            get
            {
                return image;
            }
            set
            {
                image = value;
                this.Invalidate();
            }
        }
    }
}

有什么想法吗？我需要像使用MS Paint画笔一样画画。

Answer 1

在绘制图层l2后，我只需要使图层l3无效。

借鉴控制

1 个答案: