System.NullReferenceException.

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Hi;

I get the above exception in this code line.

DataGridView1.Rows[iIndex].Cells[1].Value = iGLCount.ToString();

datagridview is defined in the Designer.cs i dont think i need the Troubleshooting tip "Use the 'new' keyword to create an object instance"
in some forums i did read that i can not modify/set cells directly so i shoul enable the edit mode like ;

DataGridView1.BeginEdit(); and i got nada.

Any ideas ?

Posted 27-Feb-11 8:03am

alperena

Updated 27-Feb-11 8:51am

DaveAuld

v2

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Sandeep Mewara 27-Feb-11 14:34pm

Good to know that my answer helped. :)

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Sandeep Mewara · Answer 1 · 2011-02-27T08:15:00

System.NullReferenceException
This simply means that you are trying to use a property of an object which is actually a NULL.

Now, looking at the line you say:

MIDL

DataGridView1.Rows[iIndex].Cells[1].Value = iGLCount.ToString();

Potential objects, which can be easily debugged, seen and rectified are:
Check sequentially:
1. iGLCount : Is this object NULL? If so, doing a ToString() would throw an error
2. DataGridView1.Rows[iIndex]: Does this return a valid row object? If yes, move ahead for third and last one
3. DataGridView1.Rows[iIndex].Cells[1] : Does this return a proper object? If not, and is a NULL, then doing a .Value would throw an error.

Now, just check which one of it is (1 or 2 or 3) and handle the same. Have a NULL check before using it.