Delay of display

Hello,

I'm making a program that displays records in a datagridview. This rows has a checkbox so the user can tick what row they like.

I want to display the number of selected items (the one the ticked) upon ticking the checkbox row.

Here is my code on counting the checked rows. But the update of the text label for the count do not happen right after I tick the box.

what should i do?

public void DisplaySelectedMSGFiles() {

int check_ctr =0;

DataGridViewCheckBoxCell oCell;

foreach (DataGridViewRow r in dgmsgfiles.Rows)

{

oCell = r.Cells[0] as DataGridViewCheckBoxCell;

if (oCell.Value!=null && oCell.Value.ToString() != "Unchecked" && oCell.Value.ToString() != "False")

{

check_ctr += 1;

}

lblselectedmsgfiles.Text = String.Format("{0} of {1} item selected", check_ctr,dgmsgfiles.RowCount);

}

Hello Dan Condes,

above program code is correct, but there is need to use Data Grid View event handler that handles cell click and cell content click event. This is because every time when cell value is changed, in this case when Data Grid View cell check box is clicked and changed state from checked to unchecked state and vice versa, those events are raised and then public void DisplaySelectedMSGFiles() must be called for updating label text value. Only this way the problem will be solved correctly.

Here is sample of program code that shows how to use those event handlers to solve this particular problem :

//
//
//
void DataGridView1CellClick(object sender, DataGridViewCellEventArgs e)
{
//
// Column index of check box column is zero
//
if(e.ColumnIndex==0)
{
//
// Set new checked state according to old one
//
if(dataGridView1[e.ColumnIndex,e.RowIndex].Value!=null)
{
if(dataGridView1[e.ColumnIndex,e.RowIndex].Value.ToString()=="True")
dataGridView1[e.ColumnIndex,e.RowIndex].Value = "False";
else
dataGridView1[e.ColumnIndex,e.RowIndex].Value = "True";
}
else
dataGridView1[e.ColumnIndex,e.RowIndex].Value = "True";
}
//
// Call method for label text update
//
DisplaySelectedMSGFiles();
}
void DataGridView1CellContentClick(object sender, DataGridViewCellEventArgs e)
{
//
// Column index of check box column is zero
//
if(e.ColumnIndex==0)
{
if(dataGridView1[e.ColumnIndex,e.RowIndex].Value!=null)
{
//
// Set new checked state according to old one
//
if(dataGridView1[e.ColumnIndex,e.RowIndex].Value.ToString()=="True")
dataGridView1[e.ColumnIndex,e.RowIndex].Value = "False";
else
dataGridView1[e.ColumnIndex,e.RowIndex].Value = "True";
}
else
dataGridView1[e.ColumnIndex,e.RowIndex].Value = "True";
}
//
// Call method for label text update
//
DisplaySelectedMSGFiles();
}
//
//
//

Those event handlers can be added to program code trough Data Grid View properties / events option in design view.

All the best,

Željko Peric

3 Replies

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Željko Perić7y ago
Hello Dan Condes,
above program code is correct, but there is need to use Data Grid View event handler that handles cell click and cell content click event. This is because every time when cell value is changed, in this case when Data Grid View cell check box is clicked and changed state from checked to unchecked state and vice versa, those events are raised and then public void DisplaySelectedMSGFiles() must be called for updating label text value. Only this way the problem will be solved correctly.

Here is sample of program code that shows how to use those event handlers to solve this particular problem :
//
//
//
void DataGridView1CellClick(object sender, DataGridViewCellEventArgs e)
{
    //
    // Column index of check box column is zero
    //
    if(e.ColumnIndex==0)
    {
        //
        // Set new checked state according to old one
        //
        if(dataGridView1[e.ColumnIndex,e.RowIndex].Value!=null)
        {
            if(dataGridView1[e.ColumnIndex,e.RowIndex].Value.ToString()=="True")
                dataGridView1[e.ColumnIndex,e.RowIndex].Value = "False";
            else
                dataGridView1[e.ColumnIndex,e.RowIndex].Value = "True";
        }
        else
            dataGridView1[e.ColumnIndex,e.RowIndex].Value = "True";
    }

    //
    // Call method for label text update
    //
    DisplaySelectedMSGFiles();
}

void DataGridView1CellContentClick(object sender, DataGridViewCellEventArgs e)
{
    //
    // Column index of check box column is zero
    //
    if(e.ColumnIndex==0)
    {
        if(dataGridView1[e.ColumnIndex,e.RowIndex].Value!=null)
        {
            //
            // Set new checked state according to old one
            //
            if(dataGridView1[e.ColumnIndex,e.RowIndex].Value.ToString()=="True")
                dataGridView1[e.ColumnIndex,e.RowIndex].Value = "False";
            else
                dataGridView1[e.ColumnIndex,e.RowIndex].Value = "True";
        }
        else
            dataGridView1[e.ColumnIndex,e.RowIndex].Value = "True";
    }

    //
    // Call method for label text update
    //
    DisplaySelectedMSGFiles();
}
//
//
//
Those event handlers can be added to program code trough Data Grid View properties / events option in design view.

All the best,
Željko Peric
Amit Gupta7y ago
Instead of working with cells and rows of gridview, I ll suggest you to play with datatable and bind that with gridview, that not only gives you what you want but can easily be maintained and filtered
Amit Gupta7y ago
What's happening to the counter variable? Doesn't it increasing?