DataGridView checkbox column - value and functionality

Question

I've added a checkbox column to a DataGridView in my C# form. The function needs to be dynamic - you select a customer and that brings up all of their items that could be serviced, and you select which of them you wish to be serviced this time around.

Anyway, the code will now add a chckbox to the beginning of the DGV. What I need to know is the following:

1) How do I make it so that the whole column is "checked" by default? 2) How can I make sure I'm only getting values from the "checked" rows when I click on a button just below the DGV?

Here's the code to get the column inserted:

DataGridViewCheckBoxColumn doWork = new DataGridViewCheckBoxColumn();
            doWork.HeaderText = "Include Dog";
            doWork.FalseValue = "0";
            doWork.TrueValue = "1";
            dataGridView1.Columns.Insert(0, doWork);

So what next? Any help would be greatly appreciated!

Answer 1

1. There is no way to do that directly. Once you have your data in the grid, you can loop through the rows and check each box like this:

   foreach (DataGridViewRow row in dataGridView1.Rows)
   {
       row.Cells[CheckBoxColumn1.Name].Value = true;
   }
   

2. The Click event might look something like this:

   private void button1_Click(object sender, EventArgs e)
   {
       List<DataGridViewRow> rows_with_checked_column = new List<DataGridViewRow>();
       foreach (DataGridViewRow row in dataGridView1.Rows)
       {
           if (Convert.ToBoolean(row.Cells[CheckBoxColumn1.Name].Value) == true)
           {
               rows_with_checked_column.Add(row);
           }
       }
       // Do what you want with the check rows
   }
   

Answer 2

private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
    DataGridViewCheckBoxCell ch1 = new DataGridViewCheckBoxCell();
    ch1 = (DataGridViewCheckBoxCell)dataGridView1.Rows[dataGridView1.CurrentRow.Index].Cells[0];

    if (ch1.Value == null)
        ch1.Value=false;
    switch (ch1.Value.ToString())
    {
        case "True":
            ch1.Value = false;
            break;
        case "False":
            ch1.Value = true;
            break;
    }
    MessageBox.Show(ch1.Value.ToString());
}

best solution to find if the checkbox in the datagridview is checked or not.

Answer 3

it took me a long time to figure out how to do this without having to loop through all the records. I have a bound datagridview-source, and all fields are bound except for the checkbox-column. So I don't have/need a loop to add each row and I didn't want to create one just for this purpuse. So after a lot of trying I finally got it. And it's actually very simple too:

First you add a new .cs File to your project with a custom-checkbox cell, e.g.

DataGridViewCheckboxCellFilter.cs:

using System.Windows.Forms;

namespace MyNamespace {
    public class DataGridViewCheckboxCellFilter : DataGridViewCheckBoxCell {
        public DataGridViewCheckboxCellFilter() : base() {
            this.FalseValue = 0;
            this.TrueValue = 1;
            this.Value = TrueValue;
        }
    }
}

After this, on your GridView, where you add the checkbox-column, you do:

// add checkboxes
DataGridViewCheckBoxColumn col_chkbox = new DataGridViewCheckBoxColumn();
{
    col_chkbox.HeaderText = "X";
    col_chkbox.Name = "checked";
    col_chkbox.CellTemplate = new DataGridViewCheckboxCellFilter();                
}
this.Columns.Add(col_chkbox);

And that's it! Everytime your checkboxes get added in a new row, they'll be set to true. Enjoy!