C# 字节数组到图像不能使用相同的字节数组

Question

完整代码

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.IO;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        //Display byte array as image
        private void button1_Click(object sender, EventArgs e)
        {
            pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
            Image img = ByteArrayToImage(File.ReadAllBytes("")); //fill with path info

            pictureBox1.Image = (Image)img.Clone();
        }

        //Convert to image from bytes
        public Image ByteArrayToImage(byte[] byteArrayIn)
        {
            using (MemoryStream ms = new MemoryStream(byteArrayIn))
            {
                ms.Position = 0;
                Image returnImage = Image.FromStream(ms);
                return returnImage;
            }
        }

        //Open Image for conversion
        private void loadImage_Click(object sender, EventArgs e)
        {
            OpenFileDialog opf = new OpenFileDialog();
            DialogResult dr = new DialogResult();
            dr = opf.ShowDialog();
            if (dr == DialogResult.OK)
            {
                pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
                pictureBox1.Image = Image.FromFile(opf.FileName);
            }
        }

        private void convertImage_Click(object sender, EventArgs e)
        {
            //Choose Path to Save To
            SaveFileDialog saveDialog = new SaveFileDialog();
            saveDialog.Title = "Choose Directory and File Name";
            saveDialog.Filter = "Canga Comix *.CCMX|*.CCMX";
            DialogResult dr = saveDialog.ShowDialog();
            if (dr == DialogResult.OK)
            {
                byte[] array;

                //Save Image
                using (MemoryStream ms = new MemoryStream())
                {
                    Image img = pictureBox1.Image;
                    img.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
                    array = ms.ToArray();
                }

                using(FileStream fs = new FileStream(saveDialog.FileName, FileMode.Create))
                {
                    fs.Write(array, 0, array.Length);
                }
            }
        }

        //clear image
        private void clearImage_Click(object sender, EventArgs e)
        {
            pictureBox1.Image = null;
        }
    }
}

这些都是相当标准的。我有一个使用这些方法的测试程序。它在pictureBox 中打开一个图像，然后将其转换为byte[] 并清除pictureBox 图像。然后你可以点击 Load byte[] ，它会在运行 ByteArrayToImage 方法时正确显示图片。

然后，如果我从我的其他程序中保存一张图片并尝试在测试程序中打开它，它会给我一个邪恶的“参数无效”错误。尽管据我所知这两个文本文档完全相同。

Answer 1

此代码包含一个常见问题。在这里，您创建一个Image 绑定到包含您的位图的流...

public Image ByteArrayToImage(byte[] byteArrayIn)
{
    using (MemoryStream ms = new MemoryStream(byteArrayIn))
    {
        ms.Position = 0;
        Image returnImage = Image.FromStream(ms);
        return returnImage;
    }
}

...而using 块在退出时处理MemoryStream 实例，这使得Image 相当无用。

您可以通过调用Clone() 获得一个管理自己的内存的Image，而不是期望您的流保留：

public Image ByteArrayToImage(byte[] byteArrayIn)
{
    using (MemoryStream ms = new MemoryStream(byteArrayIn))
    using (Image returnImage = Image.FromStream(ms))
    {
        return returnImage.Clone();
    }
}

克隆未绑定到原始流。