Question

我想制作一个将png图像合并为一个png的程序。所有图像都是78px高度，120px宽度，所以我创建了一个位图1200x78（我需要合并10个图像）它合并，但结果png中的每个图像都缩放大约x2。为什么呢？

这是我的代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Security;
using System.Drawing.Imaging;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        OpenFileDialog openFileDialog1;
        Bitmap bitmap;

        public Form1()
        {
            InitializeComponent();
            openFileDialog1 = new OpenFileDialog();
            openFileDialog1.Multiselect = true;
            openFileDialog1.Filter =
        "Images (*.PNG;*.JPG;*.GIF)|*.PNG;*.JPG;*.GIF|" +
        "All files (*.*)|*.*";
            openFileDialog1.Title = "Select images to merge";

            bitmap = new Bitmap(1200, 78);
        }

        private void button1_Click(object sender, EventArgs e)
        {
            DialogResult dr = this.openFileDialog1.ShowDialog();

            if (dr == System.Windows.Forms.DialogResult.OK)
            {
                // Read the files
                int shift = 0;
                foreach (String file in openFileDialog1.FileNames)
                {
                    // Create a PictureBox.
                    try
                    {
                        PictureBox pb = new PictureBox();
                        Image loadedImage = Image.FromFile(file);
                        pb.Height = loadedImage.Height;
                        pb.Width = loadedImage.Width;
                        pb.Image = loadedImage;
                        flowLayoutPanel2.Controls.Add(pb);

                        paintToBitmap(loadedImage, shift);

                        shift += loadedImage.Width;
                    }
                    catch (SecurityException ex)
                    {
                        //  The user lacks appropriate permissions to read files, discover paths, etc.
                        MessageBox.Show("Security error\n\n" +
                           "Error message: " + ex.Message + "\n\n" +
                            "Details (send to Support):\n\n" + ex.StackTrace
                        );
                    }
                    catch (Exception ex)
                    {
                        // Could not load the image - probably related to Windows file system permissions.
                        MessageBox.Show("!!!");
                    }
                }


                saveImage();
            }
        }

        private void paintToBitmap(Image image, int shift)
        {           
            Graphics graphics = Graphics.FromImage(bitmap);
            graphics.DrawImage(image, new Point(shift, 0));
        }

        private void saveImage()
        {
            bitmap.Save("d:\\result.png", System.Drawing.Imaging.ImageFormat.Png);
        }

        private void flowLayoutPanel2_Paint(object sender, PaintEventArgs e)
        {

        }
    }
}

Answer 1

尝试将代码更新为此

graphics.DrawImage(image, new Rectangle(shift, 0,120,78));

Answer 2

它似乎试图使图片适应你的粉红色狗的大小：P＆＃34;图片。当您使用背景填充图像时，会产生不同的方式。看到这个：

所以，问题似乎出现在图片的无形背景中。

.NET在绘制图形时缩放图像

2 个答案: