KeepWith throws Object reference not set to an instance of an object

Question

Hoping someone out there might have had the same issue as this and have found a resolution.

I'm trying to set certain rows within a table to be grouped so that if a row falls into the next page the other rows will also go across to that next page.

I'm using PdfSharp and Migradoc setting the rows KeepWith property to the index of the row i want to keep attached to.

IE:

var row = myTable.AddRow();
var rowIndex = row.Index;

foreach (var term in terms)
{
  row = myTable.AddRow();

  if (term.name == "group")
  {
    row.KeepWith = rowIndex;
  }
}

When i try and load the pdf I get an 'Object reference not set to an instance of an object' error thrown and cannot figure out why. Any help would be great.

score 11 · Accepted Answer · answered Jul 26 '11 at 13:51

11

Set KeepWith to the count of following rows you want to keep with the current row. To keep three rows together, the correct value is 2 (set at the first row of the group).

answered Jul 26 '11 at 13:51

I liked the old Stack Overflow

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Thats smashing thanks for giving me a better understanding of the usage of KeepWith – Lee Grindon Jul 26 '11 at 14:28
Sorry but my reputation is below 15 and it wont allow me to :( – Lee Grindon Jul 26 '11 at 15:51
Why the downvote? First downvote after 5 years - and without any feedback. How could I improve the answer? – I liked the old Stack Overflow Jul 28 '16 at 08:10
Should also be mentioned that, you will need to check for the remaining rows, when using KeepWith. I experienced an Exception when I only had 1 row remaining, but called `KeepWith = 2`. Downvote seems a bit harsh, cant see anything wrong. – Vincent P Aug 23 '16 at 04:53

score 1 · Answer 2 · answered Jan 14 '19 at 17:21

I was making the mistake of putting the KeepWith at the end of the rows to keep together. As Vive la déraison said, place the KeepWith on the first row of the rows to keep together.

Additionally, the int provided for the KeepWith value does NOT include the row it is set on. So to keep rows rowA, rowB, and rowC together, you would set:

rowA.KeepWith = 2;

If you're setting a KeepWith for the last rows of your table, and accidentally set the value +1 (Inclusive of the row you set it on), you will get the same "Object Not Set..." error, as you are extending the KeepWith longer than the table rows.

Gotta love those Off-By-One errors.

KeepWith throws Object reference not set to an instance of an object

2 Answers2