c# DataGridView change row backcolour if pervious value is not a match to current

Question

Hi, I'm trying to format a DataGridView so that if the Previous Cell value doesn't match the current one, then the current row's background colour is changed.
If they do match, then I need to background colour to match the colour it was previously changed to.

I found out about checking if a value is odd or even, which kind of put me in the right direction (https://csharp-station.com/how-to-test-for-even-or-odd-numbers-in-c/)

So my grid initially looks like this :

and when I run my code

        private void button1_Click(object sender, EventArgs e)   
        {              
dataGridView3.DefaultCellStyle.BackColor = Color.White;  
  
            int Counter6 = 0;  
            int seek3 = 0;  
            int perviousValue = 1;  
            int nomatch = 0;  
  
            foreach (DataGridViewRow item5 in dataGridView3.Rows)  
            {  
                seek3 = Convert.ToInt32(item5.Cells["posidDataGridViewTextBoxColumn"].Value);  
  
                if (seek3 == perviousValue)  
                {  
                    Counter6++;  
                }  
                else  
                {  
                    perviousValue = seek3;  
  
                    if (nomatch % 2 == 0)  
                    {  
                        dataGridView3.Rows[Counter6].DefaultCellStyle.BackColor = Color.LightSalmon;  
                    }  
                    else  
                    {  
                        dataGridView3.Rows[Counter6].DefaultCellStyle.BackColor = Color.White;  
  
                    }  
                    Counter6++;  
                    nomatch++;  
                }  
  
               
            }  
        }  

it kind of works

but the "11" 's (All three) should be pink, as shul the 13's. 14'th are ok.

Can any one advise where eI am going wrong, and what to do to resolve it. ?

thanks

Answer 1

For anyone following this, and for Future me looking for the solution again ( :-) ), it might not be the prettiest of code, but it (seems to) work.

        private void button1_Click(object sender, EventArgs e)   
        {  
  
            dataGridView3.DefaultCellStyle.BackColor = Color.White;  
  
            int Counter6 = 0;  
  
            //ADDED TO SOLVE ISSUE  
            int previousCounter6 = Counter6-1;  
            bool isPink = false;  
            //ADDED TO SOLVE ISSUE  
  
            int seek3 = 0;  
            int perviousValue = 1;  
            int nomatch = 0;  
  
            foreach (DataGridViewRow item5 in dataGridView3.Rows)  
            {  
                seek3 = Convert.ToInt32(item5.Cells["posidDataGridViewTextBoxColumn"].Value);  
  
                if (seek3 == perviousValue)  
                {  
                    //ADDED TO SOLVE ISSUE  
                    if (isPink == true)  
                    {  
                        if (previousCounter6 == -1)  
                        {  
                            previousCounter6 = 0;  
                        }  
                    //ADDED TO SOLVE ISSUE  
                        dataGridView3.Rows[previousCounter6].DefaultCellStyle.BackColor = Color.LightSalmon;  
                    }  
                    else  
                    {  
                        //ADDED TO SOLVE ISSUE  
                        if (previousCounter6 == -1)  
                        {  
                            previousCounter6 = 0;  
                        }  
                        //ADDED TO SOLVE ISSUE  
  
                        dataGridView3.Rows[previousCounter6].DefaultCellStyle.BackColor = Color.White;  
  
                    }  
  
                    Counter6++;  
                    //ADDED TO SOLVE ISSUE  
                    previousCounter6++;  
                    //ADDED TO SOLVE ISSUE  
                }  
                else  
                {  
                    perviousValue = seek3;  
  
                    if (nomatch % 2 == 0)  
                    {  
                        dataGridView3.Rows[Counter6].DefaultCellStyle.BackColor = Color.LightSalmon;  
                        //ADDED TO SOLVE ISSUE  
                        isPink = true;  
                        //ADDED TO SOLVE ISSUE  
                    }  
                    else  
                    {  
                        dataGridView3.Rows[Counter6].DefaultCellStyle.BackColor = Color.White;  
                        //ADDED TO SOLVE ISSUE  
                        isPink = false;  
                        //ADDED TO SOLVE ISSUE  
                    }  
                    Counter6++;  
                    //ADDED TO SOLVE ISSUE  
                    previousCounter6++;  
                    //ADDED TO SOLVE ISSUE  
                    nomatch++;  
                }  
  
               
            }  
        }