Object reference not to an instance of an object

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Dear Frnds,

I have created one Gridview checkbox column.. it have following error pls help me..
Object reference not to an instance of an object in if Statement:

C#

foreach (DataGridViewRow row in dgvScreenDetails.Rows)
           {
               DataGridViewCheckBoxCell chk = row.Cells[2] as DataGridViewCheckBoxCell;
               // number 0 represents the 1st column of dgv!

               if (Convert.ToBoolean(chk.Value) == true)
               {
                   MessageBox.Show("this cell checked");

               }
           }

Posted 24-Feb-14 23:27pm

Member 10611310

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samit kaneriya 25-Feb-14 8:04am

give your html code

3 solutions

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OriginalGriff · Answer 1 · 2014-02-24T23:33:00

Use the debugger and check, but I think you will find that row.Cells[2] is not a DataGridViewCheckBoxCell - so as returns a null, and you get an error.

Start with the debugger, and look at what type is actually is: that should tell you is you are reading the wrong column, or it's an empty cell, or what - we can't do that because we can't see your screen, we don't have access to you HDD, and we can't read your mind! :laugh:

Sanket Saxena · Answer 2 · 2014-02-25T01:42:00

Solution 3

Paste the code block will check

Posted 25-Feb-14 1:42am

Sanket Saxena

Shameel · Answer 3 · 2014-02-24T23:32:00

Solution 1

C#

DataGridViewCheckBoxCell chk = row.Cells[2] as DataGridViewCheckBoxCell;

The as keyword will return null if the type conversion failed. You need to check if the variable is null before using it in the if statement. The chk variable is null.

Posted 24-Feb-14 23:32pm

Shameel