Question

我有代码可以保存图片（Bitmap）并且它不会保存它并且每次都会抛出异常，问题是什么？

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Drawing.Imaging;
using System.IO;

namespace PicConv {
    public partial class Form1 : Form {
        Bitmap bmp;
        Bitmap bmp2;
        public Form1() {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e) {

            for (int y = 0; y < bmp.Height; y++) {
                for (int x = 0; x < bmp.Width; x++) {
                    Color c = bmp2.GetPixel(x, y);
                    byte r = c.R;
                    byte g = c.G;
                    byte b = c.B;

                    byte I = (byte)(0.3 * r + 0.59 * g + 0.11 * b);
                    Color c1 = Color.FromArgb(I, I, I);
                    bmp2.SetPixel(x, y, c1);
                }
            }
            pictureBox2.Image = bmp2;
            pictureBox2.SizeMode = PictureBoxSizeMode.StretchImage;
        }

        private void pictureBox1_Click(object sender, EventArgs e) {
            bmp = new Bitmap(@"C:\pic.bmp");
            pictureBox1.Image = bmp;
            pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
            bmp2 = (Bitmap)bmp.Clone();
        }

        private void button2_Click(object sender, EventArgs e) {
            try {
                if (bmp2 != null) {
                    bmp2.Save(@"c:\test.bmp"); // <- this throws an exception every time and won't save anything
                }
            } catch (Exception ex) {
                MessageBox.Show("Error: " + ex.Message);
            }
        }
    }
}

我让它弹出一个消息框窗口，告诉我错误是什么，它说＆＃34; GDI +中发生了一般性错误＆＃34;。

Answer 1

尝试将其保存到文件夹而不仅仅是C：。否则，我认为您需要使用管理员权限运行。

Answer 2

尝试更改加载图片的方式

using(FileStream fs = new FileStream(@"C:\temp\pic.bmp", FileMode.Open, FileAccess.Read))
{
    MemoryStream ms = new MemoryStream();
    fs.CopyTo(ms);
    ms.Seek(0, System.IO.SeekOrigin.Begin);
    bmp = (Bitmap)System.Drawing.Image.FromStream(ms);
}
pictureBox1.Image = bmp;
pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
bmp2 = (Bitmap)bmp.Clone();

请注意，它可能与您的问题无关，但最好避免在系统驱动器的根目录中写入。通常，此位置需要提升的访问权限。

用C＃保存图像

2 个答案: