以流格式保存圖片框中的圖像

Question

我想保存加載在圖片框中的圖片以流式傳輸。當我以 png 格式保存時，它可以正常工作，但是當我想以其他格式保存時，我得到了

GDI + 異常中發生通用錯誤

它的我的代碼：

Image Img = pictureBox1.Image;
byte[] inputImage = new byte[Img.Width * Img.Height];
System.IO.MemoryStream ms = new System.IO.MemoryStream();
ms.Read(inputImage, 0, Img.Width * Img.Height);

if (System.Drawing.Imaging.ImageFormat.Jpeg.Equals(Img.RawFormat))
{
    pictureBox1.Image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
}
else if (System.Drawing.Imaging.ImageFormat.Gif.Equals(Img.RawFormat))
{
    ms.Seek(0, SeekOrigin.Begin);
    pictureBox1.Image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
}
else if (System.Drawing.Imaging.ImageFormat.Png.Equals(Img.RawFormat))
{
    pictureBox1.Image.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
}
else if (System.Drawing.Imaging.ImageFormat.Bmp.Equals(Img.RawFormat))
{
    pictureBox1.Image.Save(ms, System.Drawing.Imaging.ImageFormat.Bmp);
}

Answer 1

試試這個方法：

public Stream ImageToStream(Image image, System.Drawing.Imaging.ImageFormat format)
{
    MemoryStream ms = new MemoryStream();
    image.Save(ms, format);
    return  ms;
}

並使用它：

using(Stream stream = ImageToStream(pictureBox1.Image, 
                           System.Drawing.Imaging.ImageFormat.Gif))
{
    ...
}