Why DataGridColumn not getting removed from DataGridView

Question

I have custom DataGridView control and in that control there is RefreshGrid() method which fill DataGridView by using DataSource. Now I am tring to remove few columns from that DataGridView after DataSource binding but unable to remove those, those column not getting removed but add at the end of DataGridView, when I call RefreshGrid() method again then those column get removed from DataGridView. Here is code for method RefreshGrid()

    public void RefreshGrid()
    {
        DataTable _table = AccessConnectionManagers.GetDataTableBySQLQuery("select Colm1,Colm2,Colm3 from TableName");
        //Data Source Binding with DataGridView
        this.DataSource = _table;

        if (!string.IsNullOrEmpty("Colm1"))
        {
            var _colmArray = GridRemoveColumnName.Split(new char[] { ',', ';' }, StringSplitOptions.RemoveEmptyEntries).Where(a => this.Columns.Contains(a)).Select(a => a).ToArray();

            foreach (string colm in _colmArray)
            {
                //Remove column after Source Binding
                this.Columns.Remove(colm);
            }
        }
    }

Call for RefreshGrid()

    public Form1()
    {
        InitializeComponent();
        myDataGridView1.RefreshGrid();
    }

Please find the error and suggest me the solution.

**Now I am tring to remove few columns from that DataGridView after DataSource binding** ??? Please show us the code where you are removing these columns after DataSource binding — Microsoft DN, Aug 21 '13 at 13:43
The code works OK, you can always remove the datagridviewcolumns after binding. — King King, Aug 21 '13 at 13:45
@KingKing Yes this work, but when I call `RefreshGrid()` second time — Ankush Madankar, Aug 21 '13 at 13:47
@HabibZare :) actually I have some variable over there but for understanding I replace it(It is one of Custom Grid Property) — Ankush Madankar, Aug 21 '13 at 14:03
maybe this condition is false in first call but is true in second call — Habib Zare, Aug 21 '13 at 14:04
let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/35923/discussion-between-ankush-madankar-and-habib-zare) — Ankush Madankar, Aug 21 '13 at 14:10
By calling `RefreshGrid()` method on `FormLoad` event my problem get solve.. I dont know why its isnt working when I calling same method on form Contructor.. — Ankush Madankar, Aug 22 '13 at 05:25

Chris · Accepted Answer · 2013-08-26T12:00:55.117

I found answer for this question

I need to call RefreshGrid() method on Form Load not on Form constructor, after calling it on Form Log my problem get solved. But I dont know why it wasnt working on Form constructor.

I guess you try to access columns that do not exist yet. You are using the DataGridView.AutoGenerateColumns functionnality and even if you set the DataSource property, The DatagridView won't create columns until the grid is displayed. It's why it doesn't work in form constructor, but works in form_Load event or after that the grid has been displayed.

Using form_Load is maybe a possible workaround, but I reommand you to use the DataGridView.DataBindingComplete event which is especially designed to handle this situation.

score 0 · Answer 2 · answered Aug 21 '13 at 13:46

0

You should retrieve only columns from data table that you want to display in DataGridView.

var results = _table
    .AsEnumerable()
    .Where("Add your condition")
    .Select("your columns names");

this.DataSource = results;

So now you don't need to remove any columns from DataGridView

answered Aug 21 '13 at 13:46

Pankaj Agarwal

11,191
12
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This removes/filters out rows not columns? – King King Aug 21 '13 at 13:52
@KingKing: from select statement in linq we only gets columns that we need. where cond can be remove. if not required – Pankaj Agarwal Aug 21 '13 at 13:54
I overlooked the `Select`, however this still needs the `CopyToDataTable` if the OP wants his DataSource to be a `DataTable`. I guess we have to use `Anonymous type` here to select the columns, so `CopyToDataTable` can't be used. – King King Aug 21 '13 at 13:56
@King King: Yes can do, If data table is required in Post Processing. – Pankaj Agarwal Aug 21 '13 at 13:58
@PankajAgarwal Yes, this also work, but I want those columns in DataSource so that I can do updatation in database by using DataAdaptor – Ankush Madankar Aug 21 '13 at 13:58

Ankush Madankar · Answer 3 · 2013-08-26T11:54:04.713

0

I found answer for this question

I need to call RefreshGrid() method on Form Load not on Form constructor, after calling it on Form Load my problem get solved. But I dont know why it wasnt working on Form constructor.

edited Aug 26 '13 at 11:54

answered Aug 26 '13 at 09:17

Ankush Madankar

3,689
4
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Why DataGridColumn not getting removed from DataGridView

3 Answers3

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