Using below code steps to get the basic excel styles in RadGrid Exporting data to Excel.

1. Add the event in the radgrid like below:

 OnExcelMLExportStylesCreated="rgdReport_OnExcelMLExportStylesCreated"

2. Add the event in code behind for:

protected void rgdReport_OnExcelMLExportStylesCreated(object source, GridExportExcelMLStyleCreatedArgs e)
{
   // To set the Excel cell borders style

orderStylesCollection borders = new BorderStylesCollection();

   BorderStyles borderStyle = null;

   for (int i = 1; i <= 4; i++)

   {

      borderStyle = new BorderStyles();

      borderStyle.PositionType = (PositionType)i;

      borderStyle.Color = System.Drawing.Color.Black;

      borderStyle.LineStyle = LineStyle.Continuous;

      borderStyle.Weight = 1.0;

      borders.Add(borderStyle);

   } 

  

// styles have to set for export excel

   foreach (StyleElement style in e.Styles){

      //For Header style - background color

      if (style.Id == "headerStyle"){

            style.InteriorStyle.Pattern = InteriorPatternType.Solid;

            style.InteriorStyle.Color = System.Drawing.Color.Gray;

      }

      //For alternate row style - background color

      if (style.Id == "alternatingItemStyle" || style.Id == "alternatingPriceItemStyle" || style.Id == "alternatingPercentItemStyle" || style.Id == "alternatingDateItemStyle"){

            style.InteriorStyle.Pattern = InteriorPatternType.Solid;

            style.InteriorStyle.Color = System.Drawing.Color.LightGray;

      }

      if

(

style.Id.Contains("itemStyle") || style.Id == "priceItemStyle" || style.Id == "percentItemStyle" || style.Id == "dateItemStyle")   {

      style.InteriorStyle.Pattern = InteriorPatternType.Solid;

      style.InteriorStyle.Color = System.Drawing.Color.White;

      }

     

// for each cell border styles

      foreach (BorderStyles border in borders)

      {

         style.Borders.Add(border);

      }

     

// Each cell text wrapping

      style.AlignmentElement.Attributes.Add("ss:WrapText", "1");

}

}

3. From above code we can get below styles:

  1. n excel export data get borders
  2. Export data can wrap on each cell
  3. Export data alternative rows colors
  4. Export data header styles

References

http://www.telerik.com/community/forums/aspnet-ajax/grid/radgrid-export-data-to-excel.aspx
 http://www.telerik.com/community/forums/aspnet-ajax/grid/wrapping-text-in-an-excel-cell-via-gridexcelbuilder.aspx