System.ArgumentException:参数无效

Question

我有一个页面发送html5画布数据,编码为base64 bmp图像(使用此算法http://devpro.it/code/216.html)到服务器端进程,将其转换为System.Drawing.Image对象和做一些操作.

在我的本地环境中,这工作正常,但在我的ec2实例上,我收到以下错误:

System.ArgumentException:参数无效.在System.Drawing.Image.FromStream(Stream stream,Boolean useEmbeddedColorManagement,Boolean validateImageData)中的System.Drawing.Image.FromStream(Stream stream,Boolean useEmbeddedColorManagement)

我的代码如下:

System.Drawing.Image image = null;
string b64string = "...";
byte[] sf = Convert.FromBase64String(b64string );
using (MemoryStream s = new MemoryStream(sf, 0, sf.Length))
{
   image = System.Drawing.Image.FromStream(s, false);
}
...

这是一个包含我正在测试的样本b64string的文本文件:https://docs.google.com/leaf？id = 0BzVLGmig1YZ3MTM0ODBiNjItNzk4Yi00MzI5LWI5ZWMtMzU1OThlNWEyMTU5 &hl = en_US

我也尝试了以下内容并得到了相同的结果:

System.Drawing.ImageConverter converter = new System.Drawing.ImageConverter();
image = converter.ConvertFrom(sf) as System.Drawing.Image;         

任何见解将不胜感激!

Answer 1

我仍然不知道你的问题的真正原因,但我猜它与Image类无法识别的图像格式有关.在检查二进制数据后,我可以形成您的图像.我希望这有帮助.

Bitmap GetBitmap(byte[] buf)
{
    Int16 width = BitConverter.ToInt16(buf, 18);
    Int16 height = BitConverter.ToInt16(buf, 22);

    Bitmap bitmap = new Bitmap(width, height);

    int imageSize = width * height * 4;
    int headerSize = BitConverter.ToInt16(buf, 10);

    System.Diagnostics.Debug.Assert(imageSize == buf.Length - headerSize);

    int offset = headerSize;
    for (int y = 0; y < height; y++)
    {
        for (int x = 0; x < width; x++)
        {
            bitmap.SetPixel(x, height - y - 1, Color.FromArgb(buf[offset + 3], buf[offset], buf[offset + 1], buf[offset + 2]));
            offset += 4;
        }
    }
    return bitmap;
}

private void Form1_Load(object sender, EventArgs e)
{
    using (FileStream f = File.OpenRead("base64.txt"))
    {
        byte[] buf = Convert.FromBase64String(new StreamReader(f).ReadToEnd());

        Bitmap bmp = GetBitmap(buf);
        this.ClientSize = new Size(bmp.Width, bmp.Height);
        this.BackgroundImage = bmp;
    }
}