object Reference is set to instance of an object

mohammed shamsheer

11y1.5kWindows Forms

for (int j = 0; j < dgvcheckin.Rows.Count; j++)

{

if (Convert.ToBoolean(dgvcheckin.Rows[j].Cells["RoomNo"].Value) == null)

{

dgvcheckin.Rows.Remove(dgvcheckin.CurrentRow);

}

int NumberofRooms=1;

for (int j = 0; j < dgvcheckin.Rows.Count;j++ )

{

if (dgvcheckin.Rows[j].Cells["RoomNo"].Value.ToString() != "" || dgvcheckin.Rows[j].Cells["RoomNo"].Value != null)

{

NumberofRooms=+NumberofRooms;

}

}

This is my code when compiler check the datagridview room cell it give back null then it going to exception and skip the remaining the code any body have any idea....

7 Replies

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Michal Habalcik11y ago
Accepted answer
I don't know what are you trying to accomplish.

This condition
dgvcheckin.Rows[j].Cells["RoomNo"].Value.ToString() != "" || gvcheckin.Rows[j].Cells["RoomNo"].Value != null

can be written as String.IsNullOrEmpty(dgvcheckin.Rows[j].Cells["RoomNo"].Value)
mohammed shamsheer11y ago
I want to remove the row is roomid cell is empty or null by getting dgv.rows.currentcell.Index
mohammed shamsheer11y ago
Thank u that i expected
mohammed shamsheer11y ago
thanks for quick reply .....i changed the code i checked the null values eg dgvcheckin.rows[j].cells["Roomid"].value==null { code for remove the null rows } but problem is that when if condition check for the null statement it directly goes to the catch statemnt. My condition how to check the dgv row is null or not if(dgvcheckin.rows[j].cells["Roomid"]).value!=null is condition for check the row have value
Michal Habalcik11y ago
Also, this line Convert.ToBoolean(dgvcheckin.Rows[j].Cells["RoomNo"].Value) can't be null. Either true or false, so the remove function will never be called.

Here is the documentation for Convert.ToBoolean:

http://msdn.microsoft.com/en-us/library/wh2c31dd%28v=vs.110%29.aspx?cs-save-lang=1&cs-lang=csharp#code-snippet-1
Michal Habalcik11y ago
try this:

for (int j = 0; j < dgvcheckin.Rows.Count; j++)
{
if (dgvcheckin.Rows[j].Cells["RoomNo"].Value != null && Convert.ToBoolean(dgvcheckin.Rows[j].Cells["RoomNo"].Value) == null)
{
dgvcheckin.Rows.Remove(dgvcheckin.CurrentRow);
}
}

int NumberofRooms=1;

for (int j = 0; j < dgvcheckin.Rows.Count;j++ )
{

if (dgvcheckin.Rows[j].Cells["RoomNo"].Value != null || dgvcheckin.Rows[j].Cells["RoomNo"].Value.ToString() != "" )
{

NumberofRooms=+NumberofRooms;
}
}
Kunal Vaishya11y ago
Check null with this below code

Check null value before Convert the boolean value,because null value can not be converted in any type.

Regards,
kingskunal.