感谢您西门白石在评论回答这个问题。他说：3）确保文件不在使用的任何其他（包括你的code）。

Thank you to Simon Whitehead for answering this in the comments. He said, "3) Make sure the file is not in use by anything else (including your code)."

所以，问题是，我自己的code的使用item.Image对象，并且是preventing GDI +调用Dispose（）方法就可以了。解决的办法是在对象复制到一个新的对象，然后使用该对象来写入。由此产生的code是如下：

So the problem was that my own code was using the item.Image object, and was preventing GDI+ to call the dispose() method on it. The solution was to copy the object into a new object, then use that object to "Write." The resulting code is as follows:

try
{
   using (Bitmap tempImage = new Bitmap(item.Image)) 
   {
      tempImage.Save(filePath, System.Drawing.Imaging.ImageFormat.Png);
   }    
}
catch (Exception e)
{
    Debug.WriteLine("DEBUG::LoadImages()::Error attempting to create image::" + e.Message);
}