Help out with this code please. Image from datagridview to desktop.

Question

i am displaying images into datagridview, is working fine without any problem, but when i wan to download a single image it keeps on showing me problems that i have to (Select a single cell from Attachment column). Please the code is detailed. one can try it and help out with a solution. thank you 

 

 

using System;

using System.Collections.Generic;

using System.Drawing;

using System.IO;

using System.Windows.Forms;

namespace ImageThumbnailDataGridView

{

public partial class FormMain : Form

{

private List<string> files = null;

private int numberPreviewImages = 100;

private int imageSize = 90;

private int currentStartImageIndex = 0;

private int currentEndImageIndex = 0;

//Dictionary will store the attachments

Dictionary<int, byte[]> myAttachments;

public FormMain()

{

InitializeComponent();

}

private void btnLoadImages_Click(object sender, EventArgs e)

{

if (openFileDialog.ShowDialog(this) != DialogResult.OK)

{

return;

}

files = new List<string>();

files.AddRange(openFileDialog.FileNames);

files.Sort();

if (numberPreviewImages == 1)

{

currentStartImageIndex = 0;

currentEndImageIndex = 1;

}

else

{

currentEndImageIndex = currentStartImageIndex + numberPreviewImages - 1;

}

this.LoadImages();

}

private void LoadImages()

{

try

{

if (files == null)

{

return;

}

if (this.WindowState == FormWindowState.Minimized)

{

return;

}

dataViewImages.Rows.Clear();

dataViewImages.Columns.Clear();

int numColumnsForWidth = (dataViewImages.Width - 10) / (imageSize + 20);

int numRows = 0;

int numImagesRequired = 0;

if (currentEndImageIndex > files.Count)

{

// Are we requesting to display more images than we actually have? If so then reduce

if (currentStartImageIndex == 0)

{

numImagesRequired = files.Count;

}

else

{

numImagesRequired = (currentEndImageIndex - currentStartImageIndex) - (currentEndImageIndex - _files.Count);

}

}

else

{

// Calculated the number of rows we will need for normal use

numImagesRequired = currentEndImageIndex - currentStartImageIndex;

}

numRows = numImagesRequired / numColumnsForWidth;

if (numImagesRequired % numColumnsForWidth > 0)

{

numRows += 1;

}

if (numImagesRequired < numColumnsForWidth)

{

numColumnsForWidth = numImagesRequired;

}

int numGeneratedCells = numRows * numColumnsForWidth;

// Dynamically creating the columns

for (int index = 0; index < numColumnsForWidth; index++)

{

DataGridViewImageColumn dataGridViewColumn = new DataGridViewImageColumn();

dataViewImages.Columns.Add(dataGridViewColumn);

dataViewImages.Columns[index].Width = imageSize + 20;

}

// Creating the rows

for (int index = 0; index < numRows; index++)

{

dataViewImages.Rows.Add();

dataViewImages.Rows[index].Height = imageSize + 20;

}

int columnIndex = 0;

int rowIndex = 0;

for (int index = currentStartImageIndex; index < currentStartImageIndex + numImagesRequired; index++)

{

// Load the image from the file and add to the DataGridView

Image image = Helper.ResizeImage(files[index], imageSize, imageSize, false);

dataViewImages.Rows[rowIndex].Cells[columnIndex].Value = image;

dataViewImages.Rows[rowIndex].Cells[columnIndex].ToolTipText = Path.GetFileName(files[index]);

// Have we reached the end column? if so then start on the next row

if (columnIndex == numColumnsForWidth - 1)

{

rowIndex++;

columnIndex = 0;

}

else

{

columnIndex++;

}

}

// Blank the unused cells

if (numGeneratedCells > numImagesRequired)

{

for (int index = 0; index < numGeneratedCells - numImagesRequired; index++)

{

DataGridViewCellStyle dataGridViewCellStyle = new DataGridViewCellStyle();

dataGridViewCellStyle.NullValue = null;

dataGridViewCellStyle.Tag = "BLANK";

dataViewImages.Rows[rowIndex].Cells[columnIndex + index].Style = dataGridViewCellStyle;

}

}

}

catch (Exception ex)

{

MessageBox.Show(ex.Message);

}

}

private void dataViewImages_Resize(object sender, EventArgs e)

{

this.LoadImages();

}

private void FormMain_Load(object sender, EventArgs e)

{

imageSize = 90;

}

private void button1_Click(object sender, EventArgs e)

{

if (dataViewImages.SelectedRows.Count == 1 && dataViewImages.SelectedCells[0].ColumnIndex == 1 && dataViewImages.SelectedCells[0].Value != null)

{

DownloadAttachment(dataViewImages.SelectedCells[0]);

}

else

MessageBox.Show("Select a single cell from Attachment column", "Error uploading file", MessageBoxButtons.OK, MessageBoxIcon.Error);

}

private void DownloadAttachment(DataGridViewCell dgvCell)

{

string fileName = Convert.ToString(dgvCell.Value);

//Return if the cell is empty

if (fileName == string.Empty)

return;

FileInfo fileInfo = new FileInfo(fileName);

string fileExtension = fileInfo.Extension;

byte[] byteData = null;

//show save as dialog

using (SaveFileDialog saveFileDialog1 = new SaveFileDialog())

{

//Set Save dialog properties

saveFileDialog1.Filter = "Files (*" + fileExtension + ")|*" + fileExtension;

saveFileDialog1.Title = "Save File as";

saveFileDialog1.CheckPathExists = true;

saveFileDialog1.FileName = fileName;

if (saveFileDialog1.ShowDialog() == DialogResult.OK)

{

byteData = myAttachments[dgvCell.RowIndex];

File.WriteAllBytes(saveFileDialog1.FileName, byteData);

}

}

}

}

}