Question: I am trying to create named ranges in Excel with OpenXML. I am able to add a DefinedName in the DefinedNames collection, but that does not seem to do anything. I noticed a place in the ExtendedFileProperties where the names of ranges are being saved, a structure called "TitlesOfParts". I have tried adding an entry in there but that causes excel to throw an error and the named range is not created. Here is the code I am using:

```
public void AddNamedRange(string pNamedRangeRef, string pNamedRangeName)
    {
        DefinedName _definedName = new DefinedName() { Name = pNamedRangeName, Text = pNamedRangeRef };
        _workbook.Descendants<DocumentFormat.OpenXml.Spreadsheet.DefinedNames>().First().Append(_definedName);
        DocumentFormat.OpenXml.VariantTypes.VTLPSTR _t = new DocumentFormat.OpenXml.VariantTypes.VTLPSTR() { Text = pNamedRangeName };
        _spreadsheet.ExtendedFilePropertiesPart.Properties.TitlesOfParts.VTVector.Append(_t);
        _spreadsheet.ExtendedFilePropertiesPart.Properties.TitlesOfParts.VTVector.Size++;
    }

```

Answer: 
Using the `Open XML SDK 2.0 Productivity Tool for Microsoft Office`, to define a global/workbook-wide named range is pretty easy:

```
DefinedNames definedNamesCol = new DefinedNames();    //Create the collection
DefinedName definedName = new DefinedName()
    { Name = "test", Text="Sheet1!$B$2:$B$4" };       // Create a new range
definedNamesCol.Append(definedName);                  // Add it to the collection

workbook.Append(definedNamesCol);                     // Add collection to the workbook

```
The below code did the trick for me. After this I was able to see the name ranges in excel also.

```
var wbPart = document.WorkbookPart;
 Workbook workbook = wbPart.Workbook;
 DefinedName definedName1 = new DefinedName { Name = "ColumnRange",Text = "Sheet1!$A$1:$I$1"};
DefinedName definedName2 = new DefinedName { Name = "RowRange", Text = "Sheet1!$A$1:$A$15"};
if (workbook.DefinedNames == null)
            {
                DefinedNames definedNames1 = new DefinedNames();
                definedNames1.Append(definedName1);
                definedNames1.Append(definedName2);
                workbook.DefinedNames = definedNames1;
            }

```