使用NPOI从Excel文件读取图像

Question

I'm writing a program in Visual Studio 2010 using C# to read some excel file, and I'm using the NPOI library.

The ultimate goal is to read a image in the original excel file(xlsm), copy and paste that image into the new excel file(xlsx). If it can be paste onto the same location as in the original that would be even better.

I couldn't figure out a way to copy and past directly, so my work-around is to read the image, save a copy of the image locally (as jpeg or something other), then insert the image to the new excel file.

Below is the code I use to read image and save copy.

var lst = originalWorkbook.GetAllPictures();
for (int i = 0; i < lst.Count; i++)
{
    var pic = lst[i];
    Stream s = File.Open(String.Format("{0}.jpeg", n), FileMode.Create);
    BinaryFormatter bf = new BinaryFormatter ();
    bf.Serialize(s, pic);
    s.Close();
}

When I ran the program, I'm getting an exception saying " Type 'NPOI.XXSF.UserModel.XSSFPictureData' in Assebly......is not marked as serializable ". I tried adding [Serializable] before my class, but the exception still exist.

How can I fix this serializable issue? Or is there a better way for me to achieve my ultimate goal?

Any help is appreciated. Thanks!

Answer 1

Okay, so I figured out a way to save the images locally.

var lst = originalWorkbook.GetAllPictures();
for (int i = 0; i < lst.Count; i++)
{
    var pic = (XSSFPictureData) lst[i];
    byte[] data = pic.Data;
    BinaryWriter writer = new BinaryWriter(File.OpenWrite(String.Format("{0}.jpeg", i)));
    writer.Write(data);
    writer.Flush();
    writer.Close();
}

Using the above code, I was able to successfully save all images locally as jpeg files.

However, if anyone knows a better or simpler way to copy image from one excel file to another, please help out and answer!