how to call a method when a datagridview cell value change

Question

0.00/5 (No votes)

See more:

i have a datagridview and a button on my form. when values are entered into the 2 cells of the
datagridview and the button is pressed, the numbers are multiplied and the result is displayed in the third cell. this works alright. i now want the multiplication to be done automaticaly without pressing the button. that is when the value of the cell change it should call the function responsible for the calculation.
i tryed this but it keeps genetrating the error
An unhandled exception of the type 'System.StackOverflowException' occurred in System.Data.dll
please help me out
the codes

C#

public void multiplyrows()
        {
            for (int i = 0; i < dgvSales.Rows.Count - 1; i++)
            {
                double a = Convert.ToDouble(dgvSales.Rows[i].Cells["Quantity Sold"].Value);
                double b = Convert.ToDouble(dgvSales.Rows[i].Cells["Unit Price"].Value);

                this.dgvSales.Rows[i].Cells[5].Value = (a*b).ToString("0.00");
            }
        }

C#

private void dgvSales_CellValueChanged(object sender, DataGridViewCellEventArgs e)
        {
            multiplyrows();

        }

Posted 15-Aug-13 5:30am

mikeoabban

Add a Solution

Comments

idenizeni 15-Aug-13 11:51am

The StackOverflowException is caused by your code, you are calling multiplyrows() from the CellValueChanged routine and then changing the values on the dgvSales in your multiplyrows(). Your code is 'stuck' in a loop here. Basically, everytime you enter the multiplerows() routine you trigger another call to the CellValueChanged routine which in turn calls the multiplerows() routine, this would repeat forever.

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

fjdiewornncalwe · Accepted Answer · 2013-08-15T05:35:00

1) Have you set a breakpoint in your method to see if it even gets hit?
2) Your convert calls are very dangerous as you have them coded because they assume that every cell referenced will ALWAYS contain a valid double value. The safer way to do this would be like this:

C#

double a, b;
if( double.TryParse( dgvSales.Rows[i].Cells["Quantity Sold"].Value, out a ) &&
    double.TryParse( dgvSales.Rows[i].Cells["Unit Price"].Value, out b ) )
{
   this.dgvSales.Rows[i].Cells[5].Value = (a*b).ToString("0.00");
}
else
{
   this.dgvSales.Rows[i].Cells[5].Value = "Some default value";
}

[Edit]
As noted in the comments, this does not address the root issue at hand which is your infinite loop being created by updating cells directly. The way to solve this is to have an underlying DataTable which is used as a DataSource for the DataGridView control. In the cell value changed handler, update the underlying DataTable value and then perform your calculations on that object. When complete, simply rebind your DataGridView and you should be ok. But please use the .TryParse and not the Convert to avoid conversion errors.

mikeoabban · Accepted Answer · 2013-08-16T09:51:00

thanks to you all, this is the solution

C#

private void dgvSales_CellValueChanged(object sender, DataGridViewCellEventArgs e)
{
   if (e.ColumnIndex == 2 || e.ColumnIndex == 4)
   {
  double a = Convert.ToDouble(dgvSales.Rows[e.RowIndex].Cells["Quantity Sold"].Value);
  double b = Convert.ToDouble(dgvSales.Rows[e.RowIndex].Cells["Unit Price"].Value);
  dgvSales.Rows[e.RowIndex].Cells[5].Value = (a*b).ToString("0.00");
   }
}

how to call a method when a datagridview cell value change

2 solutions

Solution 1

Solution 2

Add your solution here

Preview 0