Develop Reference

How to keep 'Absent' text in the place of 'Empty' cell base on Current HeaderName Date in gridview row data bound

Trying cell value should be 'Absent' if cell is empty base on headertext date less than and equal to today date that cell should empty, below 12,13 dates are matching with below condition but how to cell field absent base on header text date, header condition is matching with below if condition but not getting how to keep absent.
protected void gridview_trainees_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.Header)
{
GridView gridView = (GridView)sender;
var colCount = gridview_trainees.Columns.Count;
for (int i = 3; i < colCount; i++)
{
BoundField columField = (BoundField)((DataControlFieldCell)e.Row.Cells[i]).ContainingField;
DateTime CurrentColumndate = DateTime.Parse(columField.HeaderText);
if (CurrentColumndate.Date <=DateTime.Now.Date)
{
//trying cell value should be absent if cell is empty base on header
}
}
}
}
My current gridview is like below
I want ouput like this, if header text date <= today date that column empty cell should be 'Absent'

I don't typically use the default GridView and this may not be the best approach but I suspect that since there's no way to directly retrieve the CellIndex based on the Cell's HeaderRow value, it's easier to make a list of the CellIndex values that match the date criteria.
Then iterate through that list to conditionally change text in cells where the Cell.Text value matches the empty criteria.
Add a page property:
private List<int> ColIndexes = new List<int>();
This is my proposed solution based on a similar situation:
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
var row = e.Row;
if(row.RowType == DataControlRowType.Header)
{
foreach(TableCell cell in row.Cells)
{
if(DateTime.TryParse(cell.Text, out var date))
{
if(date <= DateTime.Now.Date)
ColIndexes.Add(row.Cells.GetCellIndex(cell));
}
}
}
if(row.RowType == DataControlRowType.DataRow)
{
foreach (var index in ColIndexes)
{
var cell = row.Cells[index];
if (string.IsNullOrWhiteSpace(cell.Text))
cell.Text = "Absent";
}
}
}

Changing Row Color of DataGridView Based on Cell Value

I have Data Gridview with 2 columns namely Filename and Status .The DataGridview has a Datasource setup like this
var bs = new BindingSourceAsync();
bs.DataSource = data;
dataGridView4.DataSource = bs;
The value of the Status Column is Updated using async-await method.When the Status Value is "Invalid" i need to change the the corresponding row color to red and green if its "Valid".
For this purpose i tried hooking to the CellValueChanged Event of the DataGridView
dataGridView4.CellValueChanged += DataGridView4_CellValueChanged;
But the Event is never fired.How can i solve this problem.Please advice.

yes, In RowDataBound for the gridview
protected void GridView2_RowDataBound(object sender, GridViewRowEventArgs e)
{
// check if it is the DataRow not the header row
if (e.Row.RowType == DataControlRowType.DataRow)
{
//Cell[1] is the cell contain the value for the condition
if (Convert.ToInt16(e.Row.Cells[1].Text) < 10)
{
e.Row.Cells[0].BackColor = System.Drawing.Color.Yellow;
e.Row.Cells[1].BackColor = System.Drawing.Color.Yellow;
}
else if (Convert.ToInt16(e.Row.Cells[1].Text) < 30)
{
e.Row.Cells[0].BackColor = System.Drawing.Color.Blue;
e.Row.Cells[1].BackColor = System.Drawing.Color.Blue;
}
}
}

GridView: OnRowDatabound HeaderText Equals to ColumnText with AutoGenerateColumn True c# Asp.net

I have a gridview with first columns is same as headers i.e. same value with autogeneratecolumns as true, what i need to do in RowDatabound if HeaderText Equals to Intersect of the first Column text, Change the color to Yellow. Please see the attached image of the Desireed Gridview Output.
GridViewDesiredOutput
HTML
<asp:GridView ID="GvSamples" OnRowDataBound="GvSamples_RowDataBound" runat="server" AutoGenerateColumns="True">
C#
public void BindSamplesGrid()
{
DataTable _dt = new DataTable();
_dt = BL.GetSample(_conn);
GvSamples.DataSource = _dt;
GvSamples.DataBind();
}
protected void GvSamples_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.Header)
{
for (int i = 0; i < e.Row.Cells.Count; i++)
{
if (e.Row.Cells[i].Text == e.Row.Cells[i].Text)
e.Row.Cells[i].Text = e.Row.Cells[i].Text.Replace("_", " ");
}
}
}
I am using asp.net C# Gridview.
Thank you

There are a couple of issues with your code. First of all you can only access the header row in DataControlRowType.Header, so coloring the cells as desired must be done in DataControlRowType.DataRow.
Next you are evaluating exactly the same value, so it will always be true: e.Row.Cells[i].Text == e.Row.Cells[i].Text, although this does not seem to do much except replace a _, which has nothing to do with getting the cell color to be yellow.
The below snippet does what you need. It gets the current row number and colors the correct cell yellow.
protected void GvSamples_RowDataBound(object sender, GridViewRowEventArgs e)
{
//check if the row is a datarow
if (e.Row.RowType == DataControlRowType.DataRow)
{
//get the current row number
int rowIndex = e.Row.RowIndex;
//check if the rownumber does not exceed the column count
if (rowIndex < e.Row.Cells.Count - 1)
{
//make the cell yellow
e.Row.Cells[rowIndex + 1].BackColor = Color.Yellow;
}
}
}

Highlight gridview row based on datatable values

I need to highlight gridview rows based on values from datatable.
I have highlighted values like if any particular cell values has met some conditions then I can highlight using this code.
if(int.Parse(DataBinder.Eval(e.Row.DataItem,"Risk").ToString()) > 100)
{
e.Row.BackColor = Color.FromName("#FAF7DA");
}
Now my questions is, in my rowdatabound event I want to check values in datatable and I need to highlight values in the gridview.
protected void OnRowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
DataTable dt = DataRepository.highlightRow();
string[] strInactive = dt.AsEnumerable().Select(row => row.Field<string>("product_id")).ToArray();
foreach (GridViewRow row in gvProducts.Rows)
{
for (int i = 0; i < gvProducts.Columns.Count; i++)
{
if (gvProducts.Rows[0].Cells[0].Text.Contains("how to pass array values"))
{
e.Row.BackColor = System.Drawing.Color.Red;
}
}
}
}
}
For ex:
Here the datatable will return only one column values like this,10, 20, 20. Then I need to highlight rows of these values in the gridview.

you should be able to check e.Row.DataItem for values that meet your criteria
You can do something like this in the RowDataBound event:
if (e.Row.RowType == DataControlRowType.DataRow) {
DataRowView drv = (DataRowView) e.Row.DataItem;
if( drv("Risk") == <some condition> ) {
e.Row.BackColor = Drawing.Color.Black // :)
}
}

Perhaps this is what you are looking for:
private const System.Drawing.Color HIGHLIGHT = System.Drawing.Color.Yellow;
private const System.Drawing.Color NORMAL = System.Drawing.Color.White;
protected void OnRowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
DataTable dt = DataRepository.highlightRow();
string[] strInactive = dt.AsEnumerable().Select(row => row.Field<string>("product_id")).ToArray();
foreach (var value in strInactive)
{
e.Row.BackColor = (e.Row.Cells[0].Text == value) ? HIGHLIGHT : NORMAL;
}
}
}
I do not know what is in your DataTable, so I don't know what you want to test for.

Programatically choosing a variable number of gridview rows to format

I have a gridview where I format a specific number of cells for specific rows:
protected void hoursReportGridView_OnRowDataBound(Object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
if (e.Row.RowIndex == 1 || e.Row.RowIndex == 2)
{
for (int i = 0; i < 14; i++)
{
e.Row.Cells[i].ForeColor = Color.Black;
e.Row.Cells[i].BackColor = ColorTranslator.FromHtml("#EAFDB3");
e.Row.Cells[i].Font.Bold = true;
}
}
}
}
Right now, the rows that get changed are static (row 1 and 2).
I've added functionality to the gridview and now need a dynamic number of rows formatted (between 2 and 10). The rows will always be next to eachother.
How can choose the rows dynamically?