Develop Reference

Count not empty cells in datagrid C#

I have one qwestion. How do i Count not empty cells in datagridview, and everytime I run this part of code, it got to count + SPECIFIC n NUMBER of not empty cells.
I mean ... for example, I have 100 rows, this rows will fill when program is start, row by row, I need to do something at not empty cell in row number ( SPECIFIC n NUMBER ) 25 ( it will stop fill rows proccess ), after I run again this part of code, it must do something in row 50 ( +25 ), and so on, every 25 rows. Here is my part of code.
int counter = 0;
for (int j = 0; j < dataMailist.RowCount; j++)
{
if (dataMailist.Rows[j].Cells[2].Value != null) counter++;
}
if (counter == HERE THE SPECIFIC n NUMBER)
{
buttonStart.Enabled = false;
dataMailist.Rows[i].Cells[2].Value = "Limit";
cts.Cancel();
}
Or just ignore already filled cells and count rows by not empty cell when program runs again.

if your problem is simply to step from 25 units use modulo.
counter % 25 = reminder of counter/25 = 0 each time counter is a multiple of 25.
//declare as global
int counter = 0;
{.....}
for (int j = 0; j < dataMailist.RowCount; j++)
{
if (dataMailist.Rows[j].Cells[2].Value != null) counter++;
}
if (counter % 25 == 0) //modulo
{
buttonStart.Enabled = false;
dataMailist.Rows[i].Cells[2].Value = "Limit";
cts.Cancel();
}

Building Conways game of life with C#

I am trying to calculate the Neighbour near my cells, but the code works for only the middle cells and not for the corner ones, for which I can use many if loops but I wanna know how it works with for and if loops.
I tried creating extra if loops or writing like if row ==0 etc. but everything seems to give me wrong answer. btw bool[,] grid has the values of false and true. and we need to calculate how many trues and false are their in give row/ col.
public static int CountNeighbours(bool[,] grid, int row, int col)
{
int total = 0;
for (int i = row - 1; i < row + 2; i++)
{
for (int j = col - 1; j < col + 2; j++)
{
if (grid[i, j] == grid[row, col])
{
total += 1;
}
}
}
Console.WriteLine("total neighbours for row {0} and column {1}: {2}",row,col,total-1);
return total-1;
}
The result should give perfect answer for corners and rows.

Your problem is that you count the cell itself as its own neighbour and that you don't check the boundaries of your grid.
Change your loop conditions like that:
for (int i = Math.Max(0, row - 1); i < row + 2 && i < grid.GetLength(0); i++)
{
for (int j = Math.Max(0, col - 1); j < col + 2 && j < grid.GetLength(1); j++)
{
if (i == row && j == col) continue; // skip current cell
So with Math.Max() you ensure that you don't use a negative i or j, because that would lead to an IndexOutOfRangeException.
With grid.GetLength() you get the array size in the respective dimension, because using a i or j greater or equal to that length would again raise an IndexOutOfRangeException.
And finally the last line checks that you don't count the cell in question itself.

'For' Loop being skipped?

I'm relatively new to programming, and I'm currently trying to get to grips with C#. I've reached a point where I'm learning about 'for' loops. The problem I'm stuck on is to create the shape below using only 'for' loops and the character '*' only once.
*
***
*****
*******
*********
The code I've written is below:
for (int row = 0; row < 5; row++)
{
for (int column = 0; column + row < 4; column++)
{
Console.Write(" ");
}
for (int column = 0; column + row >= 4; column++)
{
if (column - row >= 5)
break;
Console.Write("*");
}
Console.WriteLine();
}
From what I can see, the second nested 'for' loop is being skipped until the first loop is complete.
Replacing the spaces with "O", this displays the following:
OOOO
OOO
OO
O
*********
**********
***********
************
*************
**************
Can anyone see where I'm going wrong?

The problem is in the loop condition for the second nested loop, column + row >= 4. Since column starts at zero, the first execution is basically the same as row >= 4 so for any row < 5 it won't print, which is exactly the conditions of the first loop. This means all the spaces are printed, and then a bunch of stars.
You also don't need the if-statement since that is basically a second loop condition. Something like for (int column = 0; column <= row * 2; column++) would make the most sense.
You also should probably re-evaluate the outer loop, since you only want 5 lines, and you will go through 10 lines as-is.
for (int row = 0; row < 5; row++)
{
for (int column = 0; column + row < 4; column++)
{
Console.Write(" ");
}
for (int column = 0; column <= row * 2; column++)
{
Console.Write("*");
}
Console.WriteLine();
}

for (int row = 0; row < 10; row++)
{
// This code will only get run for the first 3 rows
for (int column = 0; column + row < 4; column++)
{
Console.Write(" ");
}
// This code will only get run for rows 4 and greater
for (int column = 0; column + row >= 4; column++)
{
if (column - row >= 5)
break;
Console.Write("*");
}
Console.WriteLine();
}
What you need to do is ensure your are putting the correct number of spaces followed by the correct number of * for each line.
Hint: You probably only want 5 rows not 10

This works:
for (int row = 0; row < 5; row++)
{
for (int column = 0; column < 5 + row + 1; column++)
Console.Write(column < 5 - row ? " " : "*");
Console.WriteLine();
}
*
***
*****
*******
*********

Worked out a solution:
for (int row = 0; row < 5; row++)
{
for (int column = 0; column + row < 4; column++)
{
Console.Write(" ");
}
for (int column = 0; column + row >= 0; column++)
{
if (column == (row * 2) + 1)
break;
Console.Write("*");
}
Console.WriteLine();
}
x...'s solution is probably more appropriate, being clearer and without the need for an if statement and any breaks, but you all helped me reach the answer without too much hand holding, and I appreciate that.
Thanks :D

A simple logic can be like this.
for(i=0 to 4) //since five rows
for(j=0 to 2*i-1) // is in multiple of 1, 3, 5
print(*)

Simplest way of programmatically creating a DataGridView with X columns by Y rows

In C# Winforms, I'd like to use a DataGridView as a simple widget to store information to display to the user. To this end, I'd like to create a table of say, 5x10 cells.
After some research, solutions tend to allow adding just one row or column at a time. I'd like the whole grid created initially and straight away, so I can start populating it with data, like you would with a standard C# 2D array.
What's the simplest way of going about this? A function header could look like this:
createCells(DataGridView dgv, int cols, int rows) {}
It should be quick and amenable to changing the cols and rows to a larger or smaller number later on if need be.

By the way, there might an error like:
Sum Of The Columns' FillWeight Values Cannot Exceed 65535
To avoid it, set AutoGenerateColumns property to false, and set FillWeight to 1 for each column generated:
dgv.AutoGenerateColumns = false;
for (int i = 1; i <= columns; i++)
{
dgv.Columns.Add("col" + i, "column " + i);
dgv.Columns[i - 1].FillWeight = 1;
}
for (int j = 0; j < rows; j++)
dgv.Rows.Add();

You can do by using for loops in this way:
private DataGridView DGV_Creation(DataGridView dgv, int columns, int rows)
{
for (int i = 1; i <= columns; i++)
{
dgv.Columns.Add("col" + i, "column " + i);
}
for (int j = 0; j < rows; j++)
{
dgv.Rows.Add();
}
return dgv;
}
Call it with:
this.dataGridView1 = DGV_Creation(dataGridView1, 5, 10); // 5 columns, 10 rows (empty rows)
or:
private void DGV_Creation(ref DataGridView dgv, int columns, int rows)
{
for (int i = 1; i <= columns; i++)
dgv.Columns.Add("col" + i, "column " + i);
for (int j = 0; j < rows; j++)
dgv.Rows.Add();
}
call it with:
DGV_Creation(ref this.dataGridView1, 5, 10); //5 columns, 10 rows (empty rows)

c# winforms DataGridViewRow.Index and Count

What is wrong with this code
for (int i = 1; i < dgv.Rows.Count;)
{
MessageBox.Show(dgv.Rows[i].Index.ToString());
}
I'm getting endless MsgBoxes displaying allways and only value "1"
dgv has six rows.

you forget to place i++
and also i = 0; if i = 1 you will be miss first row of gridview
for (int i = 0; i < dgv.Rows.Count;i++)
{
MessageBox.Show(dgv.Rows[i].Index.ToString());
}