Instance problem.

A Repasky

I copied some code online and everything looked well until I ran it and got an error on the return line below. Does anyone have an idea what I should do?
arep

public static Cell GetCell(WorksheetPart workSheetPart, string cellAddress)
{
return workSheetPart.Worksheet.Descendants<Cell>().SingleOrDefault(c => cellAddress.Equals(c.CellReference));
}

System.NullReferenceException: Object reference not set to an instance of an object.
at DetailReport.GenData.<>c__DisplayClass1.b__0(Cell c) in c:\CLI\CS\DetailReport\GenData.cs:line 122
at System.Linq.Enumerable.SingleOrDefault[TSource](IEnumerable`1 source, Func`2 predicate)
at DetailReport.GenData.GetCell(WorksheetPart workSheetPart, String cellAddress) in c:\CLI\CS\DetailReport\GenData.cs:line 122
at DetailReport.Program.ExtractData(String product, String reporttitle, String whereClause, String lob) in c:\CLI\CS\DetailReport\Program.cs:line 168
at DetailReport.Program.GenDetailReports() in c:\CLI\CS\DetailReport\Program.cs:line 114
at DetailReport.Program.Main(String[] args) in c:\CLI\CS\DetailReport\Program.cs:line 36

It is called this way:

Cell cell7 = GenData.GetCell(wsp1, celladdress);

5 Replies

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Vulpes13y ago
I'm not familiar with this SDK or productivity tool at all but, judging by the link you posted, the cellAddress is what you'd expect i.e. "A1", "B2", "K5" etc.

Again based on the link, I'd have thought that the code you wanted would be on these lines:

public void SetBorderAndFill(WorkbookPart wbp1, WorksheetPart wsp1)
{
Border border1 = GenData.GenerateBorder();
Fill fill1 = GenData.GenerateFill();
string celladdress = "K5"; // or whatever
Cell cell7 = GenData.GetCell(wsp1, cellAddress);
CellFormat cf1 = cell7.StyleIndex != null ? GenData.GetCellFormat(wbp1, cell7.StyleIndex).CloneNode(true) as CellFormat : new CellFormat();
cf1.FillId = GenData.InsertFill(wbp1, fill1);
cf1.BorderId = GenData.InsertBorder(wbp1, border1);
cell7.StyleIndex = GenData.InsertCellFormat(wbp1, cf1);
}
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A Repasky13y ago
That is why I said it must be in the wrong place. Here is my code the way the article talked about it. What should I use for cellAddress?

Border border1 = GenData.GenerateBorder();
Fill fill1 = GenData.GenerateFill();
string celladdress = null;
Cell cell7 = GenData.GetCell(wsp1, celladdress);
uint styleIndex = 7;
CellFormat cf1 = GenData.GetCellFormat(wbp1, styleIndex);
uint cfcount = GenData.InsertCellFormat(wbp1, cf1);
GenData.SetBorderAndFill(wbp1, wsp1);

Is the cell address like "K5"? That is the cell reference I thought. Are these calls out of order? I just used 7 for styleIndex. Just picked a number.
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Vulpes13y ago
The code should still work wherever you put it.

If 'query' isn't null, then the only other thing that could produce an exception if it's null is the parameter 'cellAddress'.

So, are you sure that this isn't null when you pass it in?
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A Repasky13y ago
It still has the same problem on the :
return query.SingleOrDefault(c => cellAddress.Equals(c.CellReference));

System.NullReferenceException: Object reference not set to an instance of an object.
at DetailReport.GenData.<>c__DisplayClass1.b__0(Cell c) in c:\CLI\CS\DetailReport\GenData.cs:line 126
at System.Linq.Enumerable.SingleOrDefault[TSource](IEnumerable`1 source, Func`2 predicate)
at DetailReport.GenData.GetCell(WorksheetPart workSheetPart, String cellAddress) in c:\CLI\CS\DetailReport\GenData.cs:line 126
at DetailReport.Program.ExtractData(String product, String reporttitle, String whereClause, String lob) in c:\CLI\CS\DetailReport\Program.cs:line 168
at DetailReport.Program.GenDetailReports() in c:\CLI\CS\DetailReport\Program.cs:line 114
at DetailReport.Program.Main(String[] args) in c:\CLI\CS\DetailReport\Program.cs:line 36

I think maybe I am putting it in the wrong place in the program. Here is the article that I am using as a basis for this.
http://stackoverflow.com/questions/15791732/openxml-sdk-having-borders-for-cell
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Vulpes13y ago
It would appear that the SingleOrDefault method is being applied to a null sequence as I can't think what else could be null.

You could see if the exception goes away if you change the code to:

public static Cell GetCell(WorksheetPart workSheetPart, string cellAddress)
{
var query = workSheetPart.Worksheet.Descendants();
if (query != null)
return query.SingleOrDefault(c => cellAddress.Equals(c.CellReference));
else
return null;
}
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