裁剪代码向右偏移，而不是鼠标位置

Posted 2023-02-25

【中文标题】裁剪代码向右偏移，而不是鼠标位置

【英文标题】：Crop code is offset to the right and not the on the mouse position

【发布时间】：2020-11-14 15:39:21

【问题描述】：

我一直在为我的数据库管理系统制作裁剪表格。但是有一个烦人的警告，当我按下鼠标左键时，绘制的矩形向右偏移并且没有从鼠标位置开始。

这是我的代码。如果你能告诉我我在哪里搞砸了，我将不胜感激。

using System;
using System.Drawing;
using System.Windows.Forms;
using System.IO;

namespace Student_File


    public partial class fUpload : Form
    
        public fUpload()
        
            InitializeComponent();
        
        private Bitmap OriginalImage;

        // True when we're selecting a rectangle.
        private bool IsSelecting = false;

        // The area we are selecting.
        private int X0, Y0, X1, Y1;
        private void BtnUpload_Click(object sender, EventArgs e)
        
            using (OpenFileDialog openFileDialog1 = new OpenFileDialog())
            
                if (openFileDialog1.ShowDialog() == DialogResult.OK)
                
                    lblFileName.Text = Path.GetFileName(openFileDialog1.FileName);
                    pictureBoxOriginal.Image = Image.FromFile(openFileDialog1.FileName);
                    OriginalImage = (Bitmap)pictureBoxOriginal.Image;
                
            
        

        private void btnExit_Click(object sender, EventArgs e)
        
            Application.Exit();
        

        private void btnSave_Click(object sender, EventArgs e)
        
            pictureBoxCropped.Image.Save(@""+ Environment.CurrentDirectory +"Temp/Temp.Jpeg", System.Drawing.Imaging.ImageFormat.Jpeg);
        

        private void pb1_MouseUp(object sender, MouseEventArgs e)
        
            // Do nothing it we're not selecting an area.
            if (!IsSelecting) return;
            IsSelecting = false;

            // Display the original image.
            pictureBoxOriginal.Image = OriginalImage;

            // Copy the selected part of the image.
            int wid = Math.Abs(X0 - X1);
            int hgt = Math.Abs(Y0 - Y1);
            if ((wid < 1) || (hgt < 1)) return;

            Bitmap area = new Bitmap(wid, hgt);
            using (Graphics gr = Graphics.FromImage(area))
            
                Rectangle source_rectangle =
                    new Rectangle(Math.Min(X0, X1), Math.Min(Y0, Y1),
                        wid, hgt);
                Rectangle dest_rectangle =
                    new Rectangle(0, 0, wid, hgt);
                gr.DrawImage(OriginalImage, dest_rectangle,
                    source_rectangle, GraphicsUnit.Pixel);
            
            // Display the result.
            pictureBoxCropped.Image = area;
        

        private void pb1_MouseDown(object sender, MouseEventArgs e)
        
            IsSelecting = true;

            // Save the start point.
            X0 = e.X;
            Y0 = e.Y;
        

        private void pb1_MouseMove(object sender, MouseEventArgs e)
        
            // Do nothing it we're not selecting an area.
            if (!IsSelecting) return;

            // Save the new point.
            X1 = e.X;
            Y1 = e.Y;

            // Make a Bitmap to display the selection rectangle.
            Bitmap bmp = new Bitmap(OriginalImage);

            // Draw the rectangle.
            using (Graphics gr = Graphics.FromImage(bmp))
            
                gr.DrawRectangle(Pens.Red,
                    Math.Min(X0, X1), Math.Min(Y0, Y1),
                    Math.Abs(X0 - X1), Math.Abs(Y0 - Y1));
            

            // Display the temporary bitmap.
            pictureBoxOriginal.Image = bmp;
        
        
    

【问题讨论】：

PictureBox.SizeMode 属性很重要。 ***.com/questions/52278722/…

【参考方案1】：

你需要从表单中获取偏移量

PropertyInfo imageRectProperty = typeof(PictureBox).GetProperty("ImageRectangle",                               BindingFlags.GetProperty | BindingFlags.NonPublic | BindingFlags.Instance);
var value = imageRectProperty.GetValue(pictureBoxOriginal, null);
if (value == null)
    return;
Rectangle rectangle = (Rectangle)value;

if (rectangle.Contains(e.Location))

    // this is your coordinate on image, not on form
    var y = e.Y - rectangle.Y;
    var x = e.X - rectangle.X;

【讨论】：

感谢您的快速回答，但版主可能删掉了我是 c# 新手的事实，您能否解释一下如何抵消表格，因为我无所适从。跨度>

我添加了一张带说明的图片。