Develop Reference

How to remove columns from ArrayList or GridView c#

Is there any way to remove "columns" from an ArrayList?
I got this site up and running before attempting populating my DropDownLists from txt files so I hard-typed each value in. Now I've made an ArrayList from each DropDownList so I can display those lists in DataGridView on the site. The only issue is that "Enabled" and "Selected" show up as columns and I cannot seem to remove the column in the ArrayList, or specify which columns to bring in when creating the ArrayList, or GridView using GridView.Columns.Remove(); because the integers 0 or 1 or 2 don't seem to correspond with anything and the site doesn't run and I can't specify a string as the column title for what to remove.
The DataGrids show up with columns as |Enabled|Selected|Text|Value|
Here's the code for this piece as it stands (You can see what I've tried out and that didn't work that I've commented away):
// Create ListArrays from DropDownLists
ArrayList BuildingList = new ArrayList(Building.Items);
ArrayList DepartmentList = new ArrayList(Department.Items);
//Building.Items.Remove("Enabled");
//Building.Items.Remove("Selected");
// Populate Building GridView
BuildingGrid.DataSource = BuildingList;
BuildingGrid.DataBind();
//BuildingGrid.Columns.Remove;
//BuildingGrid.Columns[0].Visible = false;
// Populate Department GridView
DepartmentGrid.DataSource = DepartmentList;
DepartmentGrid.DataBind();
//DepartmentGrid.Columns[0].Visible = false;
//DepartmentGrid.Columns[1].Visible = false;
I would just go ahead and create a simple 2d array in a txt file with fields for "Value" and "Text" so the DropDownList will pull it in properly, but I can't figure that out either without being terribly inefficient and confusing.
Any help would be appreciated. Thanks.

So, here's the solution I ended up at. I finally figured out how to extract everything from a txt file, and place it into the grid the way I wanted to.
// Populate Department GridView
// get all lines of csv file
string[] BuildingString = File.ReadAllLines(Server.MapPath("Content/BuildingsCSV.csv"));
string[] DepartmentString = File.ReadAllLines(Server.MapPath("Content/DepartmentsCSV.csv"));
// create new datatable
DataTable BuildingTable = new DataTable();
DataTable DepartmentTable = new DataTable();
// Building Table
// get the column header means first line
string[] tempbuild = BuildingString[0].Split(',');
// creates columns of gridview as per the header name
foreach (string t in tempbuild)
{
BuildingTable.Columns.Add(t, typeof(string));
}
// now retrive the record from second line and add it to datatable
for (int i = 1; i < BuildingString.Length; i++)
{
string[] t = BuildingString[i].Split(',');
BuildingTable.Rows.Add(t);
}
// Department Table
// get the column header means first line
string[] tempdept = DepartmentString[0].Split(',');
// creates columns of gridview as per the header name
foreach (string t in tempdept)
{
DepartmentTable.Columns.Add(t, typeof(string));
}
// now retrive the record from second line and add it to datatable
for (int i = 1; i < DepartmentString.Length; i++)
{
string[] t = DepartmentString[i].Split(',');
DepartmentTable.Rows.Add(t);
}
// assign gridview datasource property by datatable
BuildingGrid.DataSource = BuildingTable;
BuildingGrid.DataBind();
BuildingGrid.Rows[0].Visible = false;
DepartmentGrid.DataSource = DepartmentTable;
DepartmentGrid.DataBind();
DepartmentGrid.Rows[0].Visible = false;
foreach (DataRow drb in BuildingTable.Rows)
{
BuildingDrop.Items.Add(new ListItem(drb[0].ToString(), drb[1].ToString()));
}
foreach (DataRow drd in DepartmentTable.Rows)
{
DepartmentDrop.Items.Add(new ListItem(drd[0].ToString(), drd[1].ToString()));
}

Writing a excel using closed XML - adding custom column names

I need to write a list of objects to excel sheet as a table, in which each column represents object attributes or values. To the below method, Im passing column names in a separate List and data objects in a List, I managed to get the data displayed like below, but still I could not get the columns to display properly.
I referred the below documentation, but I could not find a way to get the titles display properly.
https://github.com/closedxml/closedxml/wiki/Inserting-Tables
Code
public string CreateExcelFile<T>(IEnumerable<T> list, string sheetName, string headerTitle, List<string> titles, string fileName, string savedPath)
{
var wb = new XLWorkbook();
var ws = wb.Worksheets.Add(sheetName);
ws.Cell(1, 1).Value = headerTitle; // sets excel sheet header
var rangeTitle = ws.Range(3, 1, 3, titles.Count); // range for row 3, column 1 to row 3, column titles.Count
rangeTitle.AddToNamed("Titles");
// Need to add columns names with in rangeTitle
//rangeTitle.InsertData(titles);
// write data from row 4 onwards
if (list != null && list.Any())
{
ws.Cell(4, 1).InsertData(list);
}
else
{
ws.Cell(4, 1).Value = "No data to show";
}
// styles
var titlesStyle = wb.Style;
titlesStyle.Font.Bold = true;
titlesStyle.Alignment.Horizontal = XLAlignmentHorizontalValues.Center;
titlesStyle.Fill.BackgroundColor = XLColor.Amber;
// style titles row
wb.NamedRanges.NamedRange("Titles").Ranges.Style = titlesStyle;
ws.Columns().AdjustToContents();
var filePath = savedPath + string.Format("{0}.xlsx", fileName);
wb.SaveAs(filePath);
return filePath;
}
Output excel
Output Im trying to get - I need to get values stored in titles in the Yellow highlighted row.
Can anyone help?

You could use InsertTable. The data is inserted as an Excel Table:
ws.Cell(1, 1).InsertTable(list.AsEnumerable());

I managed to get the columns to display by doing below.
// Need to add columns names with in rangeTitle
for (int i = 0; i < titles.Count; i++)
{
var columnNumber = i + 1;
ws.Cell(3, columnNumber).Value = titles[i];
}
This works for now. But, I wonder is there a better way to doing things (without manually assigning column names like above).

ws.Cell(3, 1).Value = new [] { titles };
If you set Value to an array, ClosedXML will write each object in the array to its own row, with one property of the object per column. (See https://github.com/ClosedXML/ClosedXML/wiki/Copying-IEnumerable-Collections)
In this case, the array we're passing in has only one object – an array of titles. That inner array gets written to the target row, and each item in the inner array gets written to a column in that row.

Devexpress GridView Selected Row

I have a gridList in my c# project. There is more than 100 000 records in my gridList. I want to do some operation on filtered rows. For example I filtered gridList by 'name' column ,then I want to select all filtered rows. How can I do this?
Thank you for your help.

To traverse grid rows (with grouping, sorting and filtering taking into account) use the following approach:
void TraverseRows(ColumnView view) {
for (int i = 0; i < view.DataRowCount; i++) {
object row = view.GetRow(i);
// do something with row
}
}
P.S. Please read the Traversing Rows article for details.

First you need to set OptionsSelection.MultiSelect = true property of your GridView.
Then, to select all filtered rows you can use SelectAll() method of your GridView after applying your filter.

I find another answer for tihs problem:
void TraverseRows(ColumnView view,bool selectRemove)
{
dtTemp = new Data.Medical.Follow.DSFollow.FollowRequestsDataTable();
for (int i = 0; i < gridViewList.RowCount; i++)
{
DataRow row = gridViewList.GetDataRow(gridViewList.GetVisibleRowHandle(i));
row["is_selected"] = selectRemove;
dtTemp.AddFollowRequestsRow((DSFollow.FollowRequestsRow)row);
}
}

C# winforms gridview sorting after binding data programatically

http://msdn.microsoft.com/en-us/library/system.windows.forms.datagridview.columnheadermouseclick(v=vs.110).aspx
private void dataGridView1_ColumnHeaderMouseClick(
object sender, DataGridViewCellMouseEventArgs e)
{
...
// Sort the selected column.
dataGridView1.Sort(newColumn, direction);
newColumn.HeaderCell.SortGlyphDirection =
direction == ListSortDirection.Ascending ?
SortOrder.Ascending : SortOrder.Descending;
}
public CustomersListWrapper(DataGridView gridView)
{
_gridView = gridView;
_gridView.CellClick += dgwCustomersList_CellContentClick;
_gridView.ColumnHeaderMouseClick += dgwCustomersList_ColumnHeaderMouseClick;
ClearGrid();
SetCustomersListHeader();
....
}
private void ClearGrid()
{
_gridView.Rows.Clear();
_gridView.Columns.Clear();
}
private void SetCustomersListHeader()
{
_gridView.Columns.Add(DataGridViewColumnNames.Customers.ID, "Id");
_gridView.Columns.Add(DataGridViewColumnNames.Customers.NAME, "Ime");
_gridView.Columns[1].Width = 360;
_gridView.Columns.Add(DataGridViewColumnNames.Customers.SURNAME, "Priimek");
_gridView.Columns[2].Width = 360;
_gridView.Columns.Add(DataGridViewColumnNames.Customers.ACCOUNT_NUMBER, "Št. računa");
_gridView.Columns[3].Width = 120;
_gridView.Columns.Add(DataGridViewColumnNames.Customers.CUSTOMER_NUMBER, "Št. stranke");
_gridView.Columns[4].Width = 120;
int nLastColumn = _gridView.Columns.Count - 1;
for (int i = 0; i < _gridView.Columns.Count; i++)
{
if (nLastColumn == i)
{
_gridView.Columns[i].AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill;
}
}
...
}
but the problem is that sorting is not working it is always Ascending. I am binding every time new data to the grid dynamically and looks like this reset the grid sorting,
newColumn.HeaderCell.SortGlyphDirection
has correct value but after binding data data is lost and SortGlyphDirection is None again.
can I somehow remember value of the Column of the gridview after binding?

I suppose you are binding data source from DataTable right? Changing data source resets previous sorting, I think there is more ways how handle this issue:
- store last used sorting order in variable and use DataGridView.DataSourceChanged or DataGridView.DataBindingComplete events to sort your new data source and refresh grid
- store last used sorting order and before attaching new data source sort your source DataTable to sorting order used in DataGridView and change datasource after this

You must inherit IBindingList on your datasource. On Databind.
Loop and bind this way Instead, is easier in my opinion.
dg_Transactions.Columns.Add("1", "Date");
dg_Transactions.Columns.Add("2", "Amount");
dg_Transactions.Columns.Add("3", "Description");
foreach (var row in data.Transactions)
{
var n = dg_Transactions.Rows.Add();
var i = 0;
dg_Transactions.Rows[n].Cells[i++].Value = row.Date;;
dg_Transactions.Rows[n].Cells[i++].Value = row.Amount;
dg_Transactions.Rows[n].Cells[i++].Value = row.Description;
}

How to get column name from gridview?

I would like to know how can I get a column name from a gridview? by its number not by name.
like : Name|Age|Birthday: ( so name=0 , age=1 etc...)
thanks.

You can get it like this :
gv.HeaderRow.Cells[i].Text
Or like this :
gv.Rows[0].Cells[i].Text
Rows[0] should be your header row.

//// Header column names
int gridViewCellCount = yourGridView.Rows[0].Cells.Count;
// string array to hold grid view column names.
string[] columnNames = new string[gridViewCellCount];
for (int i = 0; i < gridViewCellCount; i++)
{
columnNames[i] = ((System.Web.UI.WebControls.DataControlFieldCell)(yourGridView.Rows[0].Cells[i])).ContainingField.HeaderText;
}

simply
GridView1.Rows[0].Cells[0].Text;
try this if you want to all the cells value from each of the rows
foreach (GridViewRow r in GridView1.Rows)
{
string s = r.Cells[0].Text;
string y = r.Cells[1].Text;
}
update:
try this
foreach (TableCell Tc in GridView1.HeaderRow.Cells)
{
//if you are not getting value than find childcontrol of TabelCell.
string sssb = Tc.Text;
foreach (Control ctl in Tc.Controls)
{
//Child controls
Label lb = ctl as Label;
string s = lb.Text;
}
}

Revisiting this old question.... it's possible to get the field names of the data bound to a GridView with this kind of code. This makes a dictionary of colnum and field name.
private static IDictionary<int, string> GetGridViewFieldNames(object grid)
{
var names = new Dictionary<int, string>();
var view = grid as GridView;
if (view != null) {
for (var i = 0; i < view.Columns.Count; i++) {
var field = view.Columns[i] as BoundField;
if (field != null) {
names.Add(i, field.DataField);
}
}
}
return names;
}

This is not the answer to the question. It is only the answer if you never change the header text in the gridview. The asker of the question wanted to get the database field name by index.
I've seen a number of "answers" which only provide the text in the selected row of a gridview, or the header text which both do not answer the question that was asked...
You may ask why? If you were going to do audits of updates in a system and wanted to compare old values and new values and only update if they change and want to indicate which field was updated how do you show the database table field name at the index of the loop.
For instance:
Protected Sub gv_RowUpdating(sender As Object, e As System.Web.UI.WebControls.GridViewUpdateEventArgs)
Dim intValCount As Integer = Integer.Parse(e.NewValues.Count)
If intValCount > 0 Then
Dim i As Integer = 0
For i = 0 To intValCount - 1
If Not e.OldValues(i).Equals(e.NewValues(i)) Then
' values have changed, audit the change
Sys.Audits.General(intID, "the_database_table", <the table field by index(i)>, e.OldValues(i).ToString, e.NewValues(i).ToString)
End If
i += 1
Next
End If
End Sub
So the questions is how do you get the database table field name by index via code behind? I too have been searching for this and all the "answers" that I've seen are not the answers I think some of us are really looking for. All the mentioned methods I've seen here are not bullet proof references to a database tables field name.

Its easy: Here i read the gridview header text for each header cell and add them as new columns to a data table.
DataTable dt = new DataTable();
foreach(DataControlFieldHeaderCell column in yourGridview.HeaderRow.Cells)
{
dt.Columns.Add(column.Text.Trim().Replace(" ", ""));
}
//Make sure you do all this after yourGridview.DataBind();
//If you do not want to bind data first simply bind an empty list like so:
/* yourGridview.DataSource = new List<string>();
yourGridview.DataBind(); */