c#使用System.Drawing.Image超出内存异常

Question

我想用2张图片创建一个pdf.其中一个图像是文本,另一个是在第一个图像之上绘制的水印.好吧,当我加载第一个图像时一切正常,但后来我尝试加载水印图像并获得"Out of Memory"异常.我有记忆(打印内存使用量大约是20MB)并且可以在我的计算机中打开图像(我使用的是我从谷歌那里测试的,直到我没有得到真正的图像).

我得到异常的代码就是这个:

      using (System.Drawing.Image imgOriginal = System.Drawing.Image.FromFile(sOriginalPath, true))
      {
        using (System.Drawing.Image imgLogo = System.Drawing.Image.FromFile(sLogoPath, true)) //This is where it throws the exception
        {
          using (Graphics gra = Graphics.FromImage(imgOriginal))
          {
            Bitmap bmLogo = new Bitmap(imgLogo);
            int nWidth = bmLogo.Size.Width;
            int nHeight = bmLogo.Size.Height;
            int nLeft = (imgOriginal.Width / 2) - (nWidth / 2);
            int nTop = (imgOriginal.Height / 2) - (nHeight / 2);
            gra.DrawImage(bmLogo, nLeft, nTop, nWidth, nHeight);
          }
          return imgOriginal;
        }
      }

我见过像我这样的其他问题但是:

• 它似乎不是内存问题
• 它似乎不是图像问题

你能帮助我吗？谢谢 :)

Answer 1

问题

您正在构建一个对象

  using (System.Drawing.Image imgOriginal = System.Drawing.Image.FromFile(sOriginalPath, true))

然后你回来了......但是它已经被处理掉了......你需要通过用一个使用来解开它来处理它...这需要处理掉这个对象.

其他问题

bitmap也是一个内存泄漏,需要用一个包含using或 dispose隐式调用.

最终功能示例

public System.Drawing.Image GetImage(string sOriginalPath, string sLogoPath)
{
  System.Drawing.Image imgOriginal = System.Drawing.Image.FromFile(sOriginalPath, true);
  using (System.Drawing.Image imgLogo = System.Drawing.Image.FromFile(sLogoPath, true)) //This is where it throws the exception
  {
    using (Graphics gra = Graphics.FromImage(imgOriginal))
    {
      using(Bitmap bmLogo = new Bitmap(imgLogo)) 
      {
        int nWidth = bmLogo.Size.Width;
        int nHeight = bmLogo.Size.Height;
        int nLeft = (imgOriginal.Width / 2) - (nWidth / 2);
        int nTop = (imgOriginal.Height / 2) - (nHeight / 2);
        gra.DrawImage(bmLogo, nLeft, nTop, nWidth, nHeight);
      }
    }
  }
  return imgOriginal;
}

示例控制台应用程序演示

我测试了下面的内容,它按预期工作.

using System.Drawing;

namespace SO_Test
{
    class Program
    {
        static void Main(string[] args)
        {
            using(Image newImage = GetImage("C:\\Users\\username\\Pictures\\image.png", "C:\\Users\\username\\Pictures\\watermark.jpg"))
            {
                newImage.Save("C:\\Users\\username\\Pictures\\newImage.png");
            }
        }

        static Image GetImage(string sOriginalPath, string sLogoPath)
        {
            Image imgOriginal = Image.FromFile(sOriginalPath, true);
            using (Image imgLogo = Image.FromFile(sLogoPath, true)) //This is where it throws the exception
            {
                using (Graphics gra = Graphics.FromImage(imgOriginal))
                {
                    using (Bitmap bmLogo = new Bitmap(imgLogo))
                    {
                        int nWidth = bmLogo.Size.Width;
                        int nHeight = bmLogo.Size.Height;
                        int nLeft = (imgOriginal.Width/2) - (nWidth/2);
                        int nTop = (imgOriginal.Height/2) - (nHeight/2);
                        gra.DrawImage(bmLogo, nLeft, nTop, nWidth, nHeight);
                    }
                }
            }
            return imgOriginal;
        }
    }
}