How to get the formatted value of cell in GridView?

Hello,
first, this is the screenshot of my test program (I have also attached it, project TelerikTestReal in solution).

I have two types of formatting, first formatting is by FormatString property of column, R/Fi/Min/Max columns have FormatString set to {0:F3}. There is also some formatting in CellFormatting event for hiding some cells and special formatting for replacing Test Type with subitem name for subitem rows.

I know Value property contains "raw" data from bound property, but there is no Text property in GridViewCellInfo object. So the first question was how to get formatted value of cell? I know GridView uses virtualization and it formats data only for visual cells, but is there any way to format value programatically?

		private void tsBtnTest_Click(object sender, EventArgs e)
		{
			GridViewCellInfo cellMin = radGridView1.Rows[3].Cells["colMin"];
			var val = cellMin.Value;
			//var text = cellMin.Text;
			GridViewCellInfo cellSub = radGridView1.Rows[8].Cells["colTestType"];
			var valSub = cellSub.Value;
		}

About copy, when I copy (by ctrl+C or context menu) some cells, I get raw data to clipboard. For example, if you copy cell in second row in Min column and paste it to notepad, you get '10,2', not '10,200' as it's formatted by FormatString property, or if you copy cell in Test Type column in row next to P7.2, it copies null, not 'Vyska' as it's formatted by CellFormatting event. Generally, I want to copy data as it's displayed in GridView, not the raw data from bound object properties. And about Copying event, I don't want to have own formatting, I would like to get output of standard formatting procedure, as it displayed in GridView.

But maybe we should discuss getting formatted value programatically first and not deal with copying.

The provided project is greatly appreciated. 

Thank you for elaborating on your first question. Indeed, the Text property is available only for the visual element. This comes from the visualization mechanism of the control. As the cells are virtualized only their underneath object is changed while scrolling. What you can do here is to use the Tag property of the GridViewCellInfo. In the CellFormatting, you can format the value and the result can be stored in the Tag property. Then you can use it at a later stage to get the formatted value.

private void radGridView1_CellFormatting(object sender, CellFormattingEventArgs e)
{
	if ((e.ColumnIndex < 0) || (e.RowIndex < 0))
		return;
. . . . . . . .// your code here
	(e.CellElement as GridDataCellElement).RowInfo.Cells[e.CellElement.ColumnIndex].Tag = e.CellElement.Text;
}

As for the copy functionality, as I mentioned, the copy mechanism works with the raw data. If you want to keep the approach with the formatting you will need to manually handle the copy event. What I could suggest instead is to format your data before applying it to the control. You could expose additional properties to your business object which will represent the format value. I think that this will be easier to implement and I hope that this way will work for you.

The underneath cell object also exposes the Tag property. My approach will not set the Tag property of the visual cell but on the cell info object underneath the visual cell. In a few words, the following code will return GridViewCellInfo object:

(e.CellElement as GridDataCellElement).RowInfo.Cells[e.CellElement.ColumnIndex]

I am using its Tag property, not the property of the visual cell. 

Currently, the control does not expose a similar method to the GetFormattedValue of the MS DataGrid. The other approach which I can suggest is formatting the data before applying it to the control. However, you have stated that this one is not working for you.

Hello,

I have found out solution for standard formatting. I have looked to Telerik sources, trying to find out what GridView does with FormatString property. I have found out RadDataConverter class, which is used also for formatting in GridView. Its Format method gets 3 parameter:
- value, which I can get from GridViewCellInfo object
- targetType, which is set to typeof(string) by default in GridDataCellElement.ApplyFormatString
- converstionInfoProvider, which is also implemented by GridViewDataColumn

So, this code works for me to do standard formatting of value by FormatString property of column. Do you think this code is ok, or is there any problem in this?

private void tsBtnTest_Click(object sender, EventArgs e)
{
	GridViewCellInfo cellMin = radGridView1.Rows[3].Cells["colMin"];
	var val = cellMin.Value;

	var rdc = RadDataConverter.Instance;
	var col = radGridView1.Columns[cellMin.ColumnInfo.Index];
	object formattedValue = rdc.Format(val, typeof(string), col);
}

Problem is, that this code doesn't know anything about custom formatting in CellFormatting event, of course. I have tried to find out also what GridView does with CellFormatting event, but I haven't understood this, and it's also related to visual cells, of course. So, my idea is to create other method similar to my CellFormatting event handler, do the same with similar parameters, and use this for getting formatted value. And I can do similar with background color etc. I can use this method also in CellFormatting event handler, so that it doesn't have to be written twice. Something like this:

private void tsBtnTest_Click(object sender, EventArgs e)
{
	var min3 = GetFormattedValue(radGridView1, "colMin", 3); // 10,400
	var typ3 = GetFormattedValue(radGridView1, "colTestType", 3); // RelVyska
	var typ9 = GetFormattedValue(radGridView1, "colTestType", 9); // ____Tvar
}

private object GetFormattedValue(RadGridView gridView, string colName, int rowIndex)
{
	GridViewCellInfo cellInfo = gridView.Rows[rowIndex].Cells[colName];
	object value = cellInfo.Value;

	if (DoCustomCellFormatting(gridView, colName, rowIndex, value, out object formattedValue))
		return formattedValue;

	GridViewDataColumn col = gridView.Columns[colName];
	return DoStandardFormatting(value, col);
}

private object DoStandardFormatting(object value, IDataConversionInfoProvider conversionInfoProvider)
{
	RadDataConverter rdc = RadDataConverter.Instance;
	return rdc.Format(value, typeof(string), conversionInfoProvider);
}

private bool DoCustomCellFormatting(RadGridView gridView, string colName, int rowIndex, object value, out object formattedValue)
{
	formattedValue = value;

	var ed = gridView.Rows[rowIndex].DataBoundItem as TestParEditorItem;
	if (ed == null)
		return false;

	bool isSub = ed.IsSubItem;
	bool hasSub = !isSub && ed.SubItems.Count > 0;

	switch (colName)
	{
		case "colR":
		case "colFi":
		case "colComment":
			if (isSub)
			{
				formattedValue = "";
				return true;
			}
			break;

		case "colMin":
		case "colMax":
			if (hasSub)
			{
				formattedValue = "";
				return true;
			}
			break;

		case "colTestType":
			if (isSub)
			{
				formattedValue = "   " + ed.SubItemName;
				return true;
			}
			break;
	}

	return false;
}

In a case, you want to force control to refresh itself, you can call the Refresh() method:

this.radGridView1.MasterTemplate.Refresh();

This way all the formatting events will be called. This way if you have a specific formatting that needs to be reflected in the RadGridView on a specific event, you can call the method.