Develop Reference

C#, SQLite - Calculate each cells value and put in another cells of DataGridView

I want to apply formula (Basic_Salary/MonthDays)*Workingdays and put its result in Final Amount:
Here is my code but when I run program it shows:
System.InvalidCastException: Unable to cast object of type 'System.Windows.Forms.DataGridViewRow' to type 'System.Windows.Forms.DataGridView'.
private void dataGridView1_CellLeave(object sender, DataGridViewCellEventArgs e)
{
foreach (DataGridView row in dataGridView1.Rows)
{
row.SelectedCells[dataGridView1.Columns["Final_Amount"].Index].Value =
Convert.ToDouble(row.SelectedCells[dataGridView1.Columns["Basic_Salary"].Index].Value) *
Convert.ToDouble(row.SelectedCells[dataGridView1.Columns["WorkingDays"].Index].Value);
}
}

Note: Instead of doing those inside CellLeave event doing them after clicking a button like Calculate.
A working code can be something like this:
Data:
+--+--------------+-------------+---------+--------+
|..| Basic_Salary | WorkingDays | monthNo | YearNo |
+--+--------------+-------------+---------+--------+
|..| 12000 | 20 | 1 | 2017 |
|..| 12000 | 20 | 3 | 2017 |
|..| 13000 | 22 | 2 | 2017 |
|..| 13000 | 21 | 4 | 2017 |
+--+--------------+-------------+---------+--------+
Code:
//// use this condition if you don't have that column in your data-source
if (dataGridView.Columns.Contains("Final_Amount") == false)
{
dataGridView.Columns.Add("Final_Amount", "Final Amount");
}
dataGridView.Refresh();
//// I extract indexes of my needed columns
var colIndexFinalAmount = dataGridView.Columns["Final_Amount"].Index;
//// when you know `DataPropertyName` of the column instead of its name use a way like this
var colIndexBasicSalary = dataGridView.Columns.OfType<DataGridViewColumn>().SingleOrDefault(w=> w.DataPropertyName == "Basic_Salary").Index;
var colIndexWorkingDays = dataGridView.Columns.OfType<DataGridViewColumn>().SingleOrDefault(w => w.DataPropertyName == "WorkingDays").Index;
var colIndexYearNo = dataGridView.Columns.OfType<DataGridViewColumn>().SingleOrDefault(w => w.DataPropertyName == "YearNo").Index;
var colIndexMonthNo = dataGridView.Columns.OfType<DataGridViewColumn>().SingleOrDefault(w => w.DataPropertyName == "MonthNo").Index;
//// using a simple for is better in this situation
for (var i = 0; i < dataGridView.RowCount - 1; i++)
{
//// extract values from your cells but in an expected type (mine is double as my final amount will be double)
var bs = double.Parse(dataGridView.Rows[i].Cells[colIndexBasicSalary].Value.ToString());
var wd = double.Parse(dataGridView.Rows[i].Cells[colIndexWorkingDays].Value.ToString());
//// A way of getting days of a month is this:
var yn = int.Parse(dataGridView.Rows[i].Cells[colIndexYearNo].Value.ToString());
var mn = int.Parse(dataGridView.Rows[i].Cells[colIndexMonthNo].Value.ToString());
var md = (double)DateTime.DaysInMonth(yn, mn);
//// now, just calculate what you want and set it as `Value` like this:
dataGridView.Rows[i].Cells[colIndexFinalAmount].Value = bs / md * wd;
}
Result will be:
+--+--------------+-------------+---------+--------+------------------+
|..| Basic_Salary | WorkingDays | monthNo | YearNo | Final Amount |
+--+--------------+-------------+---------+--------+------------------+
|..| 12000 | 20 | 1 | 2017 | 7741.93548387097 |
|..| 12000 | 20 | 3 | 2017 | 7741.93548387097 |
|..| 13000 | 22 | 2 | 2017 | 10214.2857142857 |
|..| 13000 | 21 | 4 | 2017 | 9100 |
+--+--------------+-------------+---------+--------+------------------+

C# - DataTable Link to GridView

I'm Working on a c# projet (webform).
Is it possible to Hide the name of the column when I Bind my DataTable to the Gridview ?
This is my DataTable:
¤----------¤----------¤----------¤
| Column 1 | Column 2 | Column 3 |
¤----------¤----------¤----------¤
| Data 1 | Data 1 | Data 1 |
¤----------¤----------¤----------¤
| Data 4 | Data 5 | Data 6 |
¤----------¤----------¤----------¤
and I would like to reach this in my GridView
¤----------¤----------¤----------¤
| Data 1 | Data 1 | Data 1 |
¤----------¤----------¤----------¤
| Data 4 | Data 5 | Data 6 |
¤----------¤----------¤----------¤
Is it possible and How could I do it please ?
EDIT:
In The First Row,I have many datas which are the same. How Could I join my cells in C# on my DataTable please?
¤----------¤----------¤----------¤----------¤----------¤----------¤
| Data 1 | Data 2 |
¤----------¤----------¤----------¤----------¤----------¤----------¤
| Data 4 | Data 5 | Data 6 | Data 7 | Data 8 | Data 9 |
¤----------¤----------¤----------¤----------¤----------¤----------¤
I would Like to reach this if possible

Have you tried setting the GridView's ColumnHeadersVisible property to False?
EDIT:
DataView view = new DataView(table);
DataTable distinctValues = view.ToTable(true, "Column1", "Column2" ...);

in web form
<asp:GridView runat="server" HeaderStyle-CssClass="hide">
</asp:GridView>
in css
.hide { display: none; }

DataRow dr = dt.Rows[0];
dr.Delete();
dt.AcceptChanges();
After that bind your datatable to your grid.
Edit
protected void OnDataBound(object sender, EventArgs e)
{
GridViewRow row = new GridViewRow(0, 0, DataControlRowType.Header, DataControlRowState.Normal);
TableHeaderCell cell = new TableHeaderCell();
cell.Text = "Your text1";
cell.ColumnSpan = 3;
row.Controls.Add(cell);
cell = new TableHeaderCell();
cell.ColumnSpan = 3;
cell.Text = "Your text2";
row.Controls.Add(cell);
GridView1.HeaderRow.Parent.Controls.AddAt(0, row);
}

How to Merge DataGridView Cell in Winforms

I have some data in a grid that currently displays like this:
------------------
|Hd1| Value |
------------------
|A | A1 |
------------------
|A | A2 |
------------------
|A | A3 |
------------------
|A | A4 |
------------------
|B | B1 |
------------------
|B | B2 |
------------------
|B | B3 |
------------------
|B | B4 |
------------------
|B | B5 |
------------------
|C | C1 |
------------------
|C | C2 |
------------------
I want to make it look like this:
|Hd | Value |
------------------
|A | A1 |
----------
| | A2 |
----------
| | A3 |
----------
| | A4 |
------------------
|B | B1 |
----------
| | B2 |
----------
| | B3 |
----------
| | B4 |
----------
| | B5 |
------------------
|C | C1 |
----------
| | C2 |
------------------
Is there any way that I can merge these cells?
I have tried in many ways also google but did not find any suitable way.
If it is possible showing this data another way without using datagridview but the result is the way I have showed, that will also solve my problem.

You must first find a duplicate values
Need to two methods:
bool IsTheSameCellValue(int column, int row)
{
DataGridViewCell cell1 = dataGridView1[column, row];
DataGridViewCell cell2 = dataGridView1[column, row - 1];
if (cell1.Value == null || cell2.Value == null)
{
return false;
}
return cell1.Value.ToString() == cell2.Value.ToString();
}
in the event, cellpainting:
private void dataGridView1_CellPainting(object sender, DataGridViewCellPaintingEventArgs e)
{
e.AdvancedBorderStyle.Bottom = DataGridViewAdvancedCellBorderStyle.None;
if (e.RowIndex < 1 || e.ColumnIndex < 0)
return;
if (IsTheSameCellValue(e.ColumnIndex, e.RowIndex))
{
e.AdvancedBorderStyle.Top = DataGridViewAdvancedCellBorderStyle.None;
}
else
{
e.AdvancedBorderStyle.Top = dataGridView1.AdvancedCellBorderStyle.Top;
}
}
now in cell formatting:
if (e.RowIndex == 0)
return;
if (IsTheSameCellValue(e.ColumnIndex, e.RowIndex))
{
e.Value = "";
e.FormattingApplied = true;
}
and in form_load:
dataGridView1.AutoGenerateColumns = false;

The DataGridView control has no related properties or methods to merge cells, but you can accomplish the same using custom painting. You can use DataGridView.CellPainting event or override the Paint method.
Plus you will need to override the DataGridView.CellClick, CellEnter, CellFormatting and other methods as well in order to give your DataGridView a full featured functionality. For eg on cell click, the entire merged cell (or group of cells that constitute a merged cell) will have to be custom painted.
You can find some sample code here:
http://social.msdn.microsoft.com/forums/en-US/vbinterop/thread/5b659cbd-7d29-4da4-8b38-5d427c3762e2
http://forums.codeguru.com/showthread.php?415930-DataGridView-Merging-Cells
http://www.codeproject.com/Questions/152113/How-can-i-merge-DataGridView-Rows-Cells-with-Equal

There are some good responses on asp.net but in winforms and for this example(merging same data in columns) it is not defined.
You can use color.transparent to hide the same values in datagridview.
even by this code, same rows do not deleted and can be good for matematical calculations.
even you can define which columns to merge by your desire sort.
In this way if end of "A" was "A4" and also start of "B" was "A4" those would not be merge. which is Often more desired. (If you do not want this, better use other responses)
MergeGridviewCells(DGV,new int[] {0,1});//For example if you want to merge first columns data/then 3th column and then second column you can use new int[] {0,2,1}
private void MergeGridviewCells(DataGridView DGV, int[] idx)
{
DataGridViewRow Prev = null;
foreach (DataGridViewRow item in DGV.Rows)
{
if (Prev != null)
{
string firstCellText = string.Empty;
string secondCellText = string.Empty;
foreach (int i in idx)
{
DataGridViewCell firstCell = Prev.Cells[i];
DataGridViewCell secondCell = item.Cells[i];
firstCellText = (firstCell != null && firstCell.Value != null ? firstCell.Value.ToString() : string.Empty);
secondCellText = (secondCell != null && secondCell.Value != null ? secondCell.Value.ToString() : string.Empty);
if (firstCellText == secondCellText)
{
secondCell.Style.ForeColor = Color.Transparent;
}
else
{
Prev = item;
break;
}
}
}
else
{
Prev = item;
}
}
}
Preview:

I spent a long time looking for this as my boss didn't want to buy any off-the-shelf components. This should be submitted into the .NET code: datagridvewtextboxcell-with-span-behaviour It just works and is soo simple to use. Works with VB/C# .NET 4.5 to 6. Spans rows and columns including headers.
DataGridView.Columns.Add(new DataGridViewTextBoxColumnEx());
DataGridViewTextBoxCellEx dataGridViewCell = (DataGridViewTextBoxCellEx)DataGridView[colIdx, rowIdx];
dataGridViewCell.ColSpan = 2;
dataGridViewCell.RowSpan = 6;

How to learn and show gridview rows includes "?" data

There is a gridview which includes 6 columns. I bound the data to some columns. For example, 3 and 5 th columns have data.
I want to show There is 2 data in first columns if there is 3 data in separate columns I want to write 3 in the first column.
Column1 | Column2 | Column3 | Column4 | Column5 | Column6
2 | | stack | | overflow |
4 | sta | ck | over | flow |
1 | | | | | stcvrflw
How can I do it?
I populate the grid
e.Row.Cells[i].Text = html;
and html variable includes < table>.... some values come from db.

After you populate the grid:
for (int i = 0; i < gv.Rows.Count; i++)
{
valueCount=0;
for (int j = 1; j < gv.Columns.Count; j++)
{
if (gv.Rows[i].Cells[j].ToString()!="")
valueCount++;
}
gv.Rows[i].Cells[0].Text =valueCount.ToString();
}

How to merge gridview rows

I want to merge table but i don't know how. I have already tried many times but still can't get the right solution. Right now my gridview is like this :
Data 1 | Data 1 | Data 1 | Data 1
Data 1 | Data 1 | Data 1 | Data 1
Data 2 | Data 2 | Data 2 | Data 2
Data 2 | Data 2 | Data 2 | Data 2
And I want the gridview to be like this :
Data 1 | Data 1 | Data 1 | Data 1
| Data 1 | Data 1 |
Data 2 | Data 2 | Data 2 | Data 2
| Data 2 | Data 2 |

How to merge cells with equal values in a GridView
this will help you
The code that merges the cells is very short:
public class GridDecorator
{
public static void MergeRows(GridView gridView)
{
for (int rowIndex = gridView.Rows.Count - 2; rowIndex >= 0; rowIndex--)
{
GridViewRow row = gridView.Rows[rowIndex];
GridViewRow previousRow = gridView.Rows[rowIndex + 1];
for (int i = 0; i < row.Cells.Count; i++)
{
if (row.Cells[i].Text == previousRow.Cells[i].Text)
{
row.Cells[i].RowSpan = previousRow.Cells[i].RowSpan < 2 ? 2 :
previousRow.Cells[i].RowSpan + 1;
previousRow.Cells[i].Visible = false;
}
}
}
}
}
The last action is to add an OnPreRender event handler for the GridView:
protected void gridView_PreRender(object sender, EventArgs e)
{
GridDecorator.MergeRows(gridView);
}