Develop Reference

How to add a value at the first empty cell in column?

In my application, I have a datagridview. For each column, there is a button. If clicked, I take the column index and now want to add a user enterd value at the first (bottom or top doesn't matter) free cell of that column. If there is no empty cell, I want to create one.
I tried looping through all rows, getting the cell values and checking if they are empty.
string data = "%VALUE%";
int rowIndex = -1;
foreach (DataGridViewRow row in dataGridViewTasks.Rows)
{
data = (string) row.Cells[columnIndex].Value;
if (string.IsNullOrWhiteSpace(data))
{
rowIndex = row.Index;
break;
}
else if (row.Cells[columnIndex].RowIndex == dataGridViewTasks.Rows.Count - 1)
{
rowIndex = dataGridViewTasks.Rows.Add();
break;
}
}
if (string.IsNullOrWhiteSpace(data) && rowIndex > -1)
{
dataGridViewTasks[columnIndex, rowIndex].Value = task.name;
}
Problem with this solution is:
If for example row 1 and 2 of column A are filled, a new value in column B is added in row 3. So that is not what I want.

If I understand you correctly, it`s should work.
Try it:
private void Button1_Click(object sender, EventArgs e)
{
var columnIndex = 1;
var dataGrid = new DataGridView();
var index = GetFirstEmptyCellByColumnIndex(dataGrid, columnIndex);
dataGrid[columnIndex, index].Value = "new value";
}
private int GetFirstEmptyCellByColumnIndex(DataGridView dataGrid, int columnIndex)
{
var index = -1;
foreach (DataGridViewRow row in dataGrid.Rows)
{
if (string.IsNullOrEmpty((string)row.Cells[columnIndex].Value))
{
index = row.Index;
break;
}
}
return index != -1
? index
: dataGrid.Rows.Add();
}

set selected row datagridview by cell's value

how to set selected row on dataGridView by a string?
example..
when form_loaded...i want that dataGridView with cell "LSN" is selected
so if i have a string text = "LSN"
then that table's row with cell value "LSN" is selected..
i usually use dataGridView1.Rows[3].Selected = true; to set selected row in datagridview..
but how can i do that if i dont know row's index and only know a string ?

You would have to iterate through each row of the DataGridView until you find the value you want. You can then select the row and break out of the loop.
foreach(DataGridViewRow row in dataGridView1.Rows)
{
// 0 is the column index
if (row.Cells[0].Value.ToString().Equals("LSN"))
{
row.Selected = true;
break;
}
}
I haven't tested this example but it should give you the right idea.

Please try below code...
string txtSearchValue="LSN";
int rowIndex = -1;
DataGridViewRow row = dgv.Rows.Cast<DataGridViewRow>()
.Where(r=>r.Cells["SystemId"].Value.ToString().Equals(txtSearchValue))
.First();
rowIndex = row.Index;
dataGridView1.Rows[rowIndex].Selected = true;
without LINQ:
foreach(DataGridViewRow row in DataGridView1.Rows)
{
if(row.Cells[1].Value.ToString().Equals(txtSearchValue))
{
rowIndex = row.Index;
break;
}
}

Linq maybe?
How can I use LINQ to find a DataGridView row?
dataGridView1.Rows
dataGridView1.Rows.Cast<DataGridViewRow>().Where(x => x.Kode == "LSN").FirstorDefault()

Get value of a column and store it into an array - DataGridView

I have the following code:
int countRows = dataGridView3.SelectedRows.Count;
int rowIndex = 0;
foreach (DataGridViewRow row in dataGridView3.SelectedRows)
{
int selectedRowIndex = dataGridView3.SelectedCells[rowIndex].RowIndex;
DataGridViewRow selectedRow = dataGridView3.Rows[selectedRowIndex];
capacity = Convert.ToInt32(selectedRow.Cells["Cust_Number"].Value);
capStore.Add(capacity);
rowIndex++;
}
I try to go through each selected row in my DataGridView and store the value from the column "Cust_Number" into an ArrayList, so that I can change it later. Somehow he just grabs the second row each time I iterate and I have the same value in my ArrayList duplicated. What is wrong here?

I would try the following code :
if(dataGridView3.SelectedRows != null && dataGridView3.SelectedRows.Count > 0)
{
foreach (DataGridViewRow dgvr in dataGridView3.SelectedRows)
{
int tempVal = 0;
if(dgvr.Cells["Cust_Number"].Value != null && int.TryParse(dgvr.Cells["Cust_Number"].Value.ToString(), out tempVal))
{
capStore.Add(tempVal);
}
}
}
This is simpler and safer.

DataRow - How to cancel adding row to datatable?

I have a problem.
I have two loops (one for row, one for column) for creating data in DataTable. I want to check if cell is empty for column named "Name" and if it is empty just don't add this row. And here is a question: How to cancel adding row?
Got some code:
for (int i = 0; i < data.Count(); i++)
{
cell = data.ElementAt(i);
DataRow row;
row = dataTable.NewRow();
foreach (string column in columns)
{
if (row["Name"] == "")
{
row = null;
}
else
{
row[column] = cell;
}
}
if (row != null)
{
dataTable.Rows.Add(row);
}
}
But after next loop is starting it throws NullException: Object reference not set to an instance of an object.
Generally I want to add Rows to DataTable only those where value of cell is not empty at column called "Name" (i mean where is "").
What is the best way or easiest way to do it right?

Change it as:
....
foreach (string column in columns)
{
if (row["Name"] == "")
{
row = null;
break; //--> Add this line
}
else
{
row[column] = cell;
}
}
....

C# DataGridRow.Rows Selects the new row

I have a simple function in my program that selects the current cell, then it (FillsDown) copies the current cell into ALL the cells below it.
However my simple function places the value in the Row at the bottom which is the new row and I do not want the value to be populated here.
Heres the current code. (Where COLINDEX is just the column im referring to in my grid)
string replacestring = row.Cells[COLINDEX].Value.ToString();
foreach (DataGridViewRow row in dataGrid1.Rows)
{
if (row.Index > startrow)
{
row.Cells[COLINDEX].Value = replacestring;
}
}
Is there a simeple method/property I can check against so I dont accidently populate the last row ?
My example below uses a fake property (.Exist)
foreach (DataGridViewRow row in dataGrid1.Rows)
{
if ((row.Index > startrow) && row.Exist)
{
row.Cells[COLINDEX].Value = replacestring;
}
}

DataGridViewRow has a property called IsNewRow
And try to walk the Rows collection using the index
for(int x = startRow + 1; x < dataGrid1.Rows.Count; x++)
{
DataGridViewRow row = dataGrid1.Rows[x];
if (row.IsNewRow == false)
{
row.Cells[COLINDEX].Value = replacestring;
}
}