Grab file size through Openfiledialog and save to a List<Attachment>

Question

I’m making an application Windowsforms to send email, within this application I have an Opendialog that selects the files and saved within a: List<Attachment> AttachmentList = new List<System.Net.Mail.Attachment>();

As I add it will appear in my Gridview, however I would like to display the size of attachments as well.

I found this code that takes the file size through Openfiledialog:

var length = new System.IO.FileInfo(theDialog.FileName).Length;

How could I put this "die" inside my List<Attachment> and display it on my grid?

To display my grid: gvAnexos.DataSource = AttachmentList;

Answer 1

Has nothing direct, do another classe or use the example below:

Put a List of Fileinfo:

List<FileInfo> files = new List<FileInfo>();

Add items from Openfiledialog:

if (openFileDialog1.ShowDialog() == DialogResult.OK)
{
    files.Add(new FileInfo(openFileDialog1.FileName));
}
dataGridView1.DataSource = files.Select(c => new {
   c.Name,
   c.Length,
   c.FullName, 
   LengthDescription = fileInfoTam(c.Length)
}).ToList();

At the end you pass the list List<FileInfo> files for List<Attachment> AttachmentList:

foreach(var item in files)
{
    AttachmentList.Add(new Attachment(item.FullName));
}

To transform the size of long in Kb or Mb put this method either in a class or in the form code itself:

public string fileInfoTam(long length)
{
    double value = (length / 1024);
    string label = "Kb";
    if ((length / 1024) > 1024)
    {
        value = ((length / 1024) / 1024);
        label = "Mb";
    }

    return string.Format("{0} {1}", Math.Round(value, 4), label);
}

Reference: code given by the question user.

Another way:

Create these two classes in your project:

public class AttachmentAndFileInfo
{
    public Attachment Attachment { get; private set; }
    public FileInfo FileInfo { get; private set; }

    public AttachmentAndFileInfo(string fileName)
    {
        if (!File.Exists(fileName))
            throw new Exception("Inválid path");

        Attachment = new Attachment(fileName);
        FileInfo = new FileInfo(fileName);                
    }
}

public class AttachmentAndFileInfoList: List<AttachmentAndFileInfo>
{
    public IList ToSelectList()
    {
        return this.Select(c => new
        {
            c.Attachment.Name,
            Path = c.FileInfo.FullName,
            Length = c.FileInfo.Length,
            LengthDescription = fileInfoTam(c.FileInfo.Length)
        })
        .ToList();
    }

    public IList<Attachment> AttachmentToList()
    {
        return this.Select(c => c.Attachment).ToList();
    }

    public IList<FileInfo> FileInfoToList()
    {
        return this.Select(c => c.FileInfo).ToList();
    }

    internal string fileInfoTam(long length)
    {
        double value = (length / 1024);
        string label = "Kb";
        if ((length / 1024) > 1024)
        {
            value = ((length / 1024) / 1024);
            label = "Mb";
        }
        return string.Format("{0} {1}", Math.Round(value, 2), label);
    }
}

Now create in your form two variables:

AttachmentAndFileInfoList attFileInfo = new AttachmentAndFileInfoList();
IList<Attachment> attachmentList;

Adding items and showing in Datagridview

private void button1_Click(object sender, EventArgs e)
{
    if (openFileDialog1.ShowDialog() == DialogResult.OK)
    {
        attFileInfo.Add(new AttachmentAndFileInfo(openFileDialog1.FileName));
    }
    dataGridView1.DataSource = attFileInfo.ToSelectList();
}

Getting the Attachment list ready

private void button2_Click(object sender, EventArgs e)
{
    attachmentList = attFileInfo.AttachmentToList();
}

References:

Attachment class

Openfiledialog class

Fileinfo class