winforms 如何根据listBox中选定的索引从磁盘加载图像？

wi3ka0sx  于 2022-11-17  发布在  其他
关注(0)|答案(1)|浏览(105)

一旦我完成了绘制一个矩形我保存图像到硬盘作为位图，添加到一个listBox的图像编号和矩形的位置和大小，最后我创建了一个文本文件的信息。

private void pictureBox2_MouseUp(object sender, MouseEventArgs e)
        {
            if (e.Button != MouseButtons.Left) return;

            if (DrawingRects.Count > 0)
            {
                // The last drawn shape
                var dr = DrawingRects.Last();
                if (dr.Rect.Width > 0 && dr.Rect.Height > 0)
                {
                    rectImage = cropAtRect((Bitmap)pictureBox2.Image, dr.Rect);
                    if (saveRectangles)
                    {
                        rectangleName = @"d:\Rectangles\rectangle" + saveRectanglesCounter + ".bmp";
                        rectImage.Save(rectangleName);
                        saveRectanglesCounter++;
                    }
                    pixelsCounter = rect.Width * rect.Height;
                    pictureBox1.Invalidate();

                    // ListBox used to present the shape coordinates
                    listBox1.Items.Add($"{dr.Location}, {dr.Size}");

                    StreamWriter w = new StreamWriter(@"d:\Rectangles\rectangles.txt", true);
                    w.WriteLine(rectangleName.Substring(23) + " ===> " + $"{dr.Location}, {dr.Size}");
                    w.Close();
                }
            }
        }

其结果是：
左边是listBox，右边是文本文件的内容和硬盘上的图像。

我想做的是，当绘制矩形并且应用程序正在运行时，能够在listBox中的项目之间移动，并在pictureBox1中显示保存的图像，并且当再次运行应用程序时，读取文本文件内容，并将项目以它们在listBox中的格式添加回listBox，并且再次能够在项目之间移动，并显示图像。
不确定如何知道什么图像属于listBox中的什么项，然后如何在选定的索引事件中加载它。

private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            foreach (int x in listBox1.SelectedIndices)
            {
                
            }
        }

全码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using static System.Net.Mime.MediaTypeNames;
using static System.Windows.Forms.VisualStyles.VisualStyleElement.ProgressBar;

namespace Image_Crop
{
    public partial class Form1 : Form
    {
        System.Drawing.Image img = null;
        Rectangle rect;
        int pixelsCounter = 0;
        Color SelectedColor = Color.LightGreen;
        List<DrawingRectangle> DrawingRects = new List<DrawingRectangle>();
        Bitmap rectImage;
        int saveRectanglesCounter = 1;
        bool drawBorder = true;
        bool clearRectangles = true;
        bool saveRectangles = true;
        string rectangleName;

        public Form1()
        {
            InitializeComponent();

            pictureBox2.Image = System.Drawing.Image.FromFile(@"d:\Comparison\ConvertedBmp.bmp");
img = System.Drawing.Image.FromFile(@"d:\Comparison\radar_without_clouds.jpg");

            checkBoxDrawBorder.Checked = true;
            checkBoxClearRectangles.Checked = true;
            checkBoxSaveRectangles.Checked = true;
            
        }

        public class DrawingRectangle
        {
            public Rectangle Rect => new Rectangle(Location, Size);
            public Size Size { get; set; }
            public Point Location { get; set; }
            public Control Owner { get; set; }
            public Point StartPosition { get; set; }
            public Color DrawingcColor { get; set; } = Color.LightGreen;
            public float PenSize { get; set; } = 3f;
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (img == null)
            {
                // Create image.
                img = System.Drawing.Image.FromFile(@"d:\Comparison\ConvertedBmp.bmp");
            }
        }

        private void Form1_Paint(object sender, PaintEventArgs e)
        {

        }

        private void pictureBox2_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button != MouseButtons.Left) return;
            DrawingRects.Add(new DrawingRectangle()
            {
                Location = e.Location,
                Size = Size.Empty,
                StartPosition = e.Location,
                Owner = (Control)sender,
                DrawingcColor = SelectedColor // <= Shape's Border Color
            });
        }

        private void pictureBox2_MouseMove(object sender, MouseEventArgs e)
        {
            if (e.Button != MouseButtons.Left) return;

            var dr = DrawingRects[DrawingRects.Count - 1];
            if (e.Y < dr.StartPosition.Y) { dr.Location = new Point(dr.Rect.Location.X, e.Y); }
            if (e.X < dr.StartPosition.X) { dr.Location = new Point(e.X, dr.Rect.Location.Y); }

            dr.Size = new Size(Math.Abs(dr.StartPosition.X - e.X), Math.Abs(dr.StartPosition.Y - e.Y));
            pictureBox2.Invalidate();
        }

        private void pictureBox2_MouseUp(object sender, MouseEventArgs e)
        {
            if (e.Button != MouseButtons.Left) return;

            if (DrawingRects.Count > 0)
            {
                // The last drawn shape
                var dr = DrawingRects.Last();
                if (dr.Rect.Width > 0 && dr.Rect.Height > 0)
                {
                    rectImage = cropAtRect((Bitmap)pictureBox2.Image, dr.Rect);
                    if (saveRectangles)
                    {
                        rectangleName = @"d:\Rectangles\rectangle" + saveRectanglesCounter + ".bmp";
                        rectImage.Save(rectangleName);
                        saveRectanglesCounter++;
                    }
                    pixelsCounter = rect.Width * rect.Height;
                    pictureBox1.Invalidate();

                    // ListBox used to present the shape coordinates
                    listBox1.Items.Add($"{dr.Location}, {dr.Size}");

                    StreamWriter w = new StreamWriter(@"d:\Rectangles\rectangles.txt", true);
                    w.WriteLine(rectangleName.Substring(23) + " ===> " + $"{dr.Location}, {dr.Size}");
                    w.Close();
                }
            }
        }

        private void pictureBox2_Paint(object sender, PaintEventArgs e)
        {
            DrawShapes(e.Graphics);
        }

        private void pictureBox1_Paint(object sender, PaintEventArgs e)
        {
            if (drawBorder)
            {
                ControlPaint.DrawBorder(e.Graphics, pictureBox1.ClientRectangle, Color.Red, ButtonBorderStyle.Solid);
            }

            if (rectImage != null && DrawingRects.Count > 0)
            {
                var dr = DrawingRects.Last();
                e.Graphics.DrawImage(rectImage, dr.Rect);

                if (clearRectangles)
                {
                    DrawingRects.Clear();
                    pictureBox2.Invalidate();
                }
            }
        }

        private void DrawShapes(Graphics g)
        {
            if (DrawingRects.Count == 0) return;
            g.SmoothingMode = SmoothingMode.AntiAlias;
            foreach (var dr in DrawingRects)
            {
                using (Pen pen = new Pen(dr.DrawingcColor, dr.PenSize))
                {
                    g.DrawRectangle(pen, dr.Rect);
                };
            }
        }

        public Bitmap cropAtRect(Bitmap b, Rectangle r)
        {
            Bitmap nb = new Bitmap(r.Width, r.Height);
            using (Graphics g = Graphics.FromImage(nb))
            {
                g.DrawImage(b, -r.X, -r.Y);
                return nb;
            }
        }

        private void checkBoxDrawBorder_CheckedChanged(object sender, EventArgs e)
        {
            if(checkBoxDrawBorder.Checked)
            {
                drawBorder = true;
            }
            else
            {
                drawBorder = false;
            }

            pictureBox1.Invalidate();
        }

        private void checkBoxClearRectangles_CheckedChanged(object sender, EventArgs e)
        {
            if(checkBoxClearRectangles.Checked)
            {
                clearRectangles = true;
            }
            else
            {
                clearRectangles = false;
            }

            pictureBox2.Invalidate();
        }

        private void checkBoxSaveRectangles_CheckedChanged(object sender, EventArgs e)
        {

        }

        private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            foreach (int x in listBox1.SelectedIndices)
            {
                
            }
        }
    }
}
winforms

1条答案

按热度按时间
jecbmhm3

jecbmhm31#

对不起，我隐藏了一些代码，希望你能理解。你可以使用Dictionary来匹配名称和路径：

Dictionary<string, string> FileList = new Dictionary<string, string>();

private void pictureBox2_MouseUp(object sender, MouseEventArgs e)
{
    // ...
    if (saveRectangles)
    {
        // ...
        FileList.Add($"{dr.Location}, {dr.Size}", rectangleName);
    }
    // ...
}

private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
{
    yourPictureBox.Image = Image.FromFile(FileList
        .Where(x => x.Key == ((ListBox)sender).SelectedItem?.ToString())
        .Select(x => x.Value).First()
    );
}

如果以后需要保存这些密钥对，我觉得保存到JSON格式的配置文件中会比较方便，要做到这一点，需要连接Newtonsoft.Json包，这个包的文档是here。
以下是保存和加载路径的一个小示例：

// Path of demo config file
string Path = $@"{Environment.CurrentDirectory}\data.json";
Dictionary<string, string> PathList = new Dictionary<string, string>();

// Checking config file data.json in current directory
if(!File.Exists(Path))
{
    // Loading demos data if config file not found
    PathList.Add("path1", "value1");
    PathList.Add("path2", "value2");
}            
else
{
    // If demo config file found - upload him
    // by specifying the type Dictionary<string, string>
    using (StreamReader sr = new StreamReader(Path))                
        PathList = JsonConvert.DeserializeObject<Dictionary<string, string>>(sr.ReadToEnd());                
}

// Showing the config keys
ListBoxKeys.Items.AddRange(PathList.Select(x => x.Key).ToArray());
// Showing the config value by selected index
ListBoxKeys.SelectedIndexChanged += (s, e) =>
{
    LabelValue.Text = PathList
        .Where(x => x.Key == ((ListBox)s).SelectedItem?.ToString())
        .Select(x => x.Value).First();
};

// Saving data list to demo config file
ButtonSave.Click += (s, e) =>
{
    using (StreamWriter sw = new StreamWriter(Path))
        sw.WriteLine(JsonConvert.SerializeObject(PathList, Formatting.Indented));
};

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