object cannot be cast from dbnull to other types

habib ullah

when we run the program then show the following error

i vahe calculate the datagraid view cell

int sum = 0;

for (int a = 0; a < dataGridView1.Rows.Count; a++)

{

sum += Convert.ToInt32(dataGridView1.Rows[a].Cells[2].Value);

}

label5.Text= sum.ToString();

}

4 Replies

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ketan borsdiya9y ago
Accepted answer
Hi Habib,
Replace line
sum += Convert.ToInt32(dataGridView1.Rows[a].Cells[2].Value);

With

sum += string.IsNullOrEmpty(dataGridView1.Rows[a].Cells[2].Value.ToString()) ? 0 : Convert.ToInt32(dataGridView1.Rows[a].Cells[2].Value);
habib ullah9y ago
Thank you sir for your your feed back this answar is right its works for me
Rafnas T P9y ago
check you grid , I think in grid in 3rd cloumn you have some where null or empty value
thats why you are getting this error

to avoid this you can do the following changes
add this checking red line in your code to skip empty or null values
int sum = 0;
for (int a = 0; a < dataGridView1.Rows.Count; a++)
{
if(dataGridView1.Rows[a].Cells[2].Value!=null && dataGridView1.Rows[a].Cells[2].Value!="")
sum += Convert.ToInt32(dataGridView1.Rows[a].Cells[2].Value);
}
label5.Text= sum.ToString();
}
Amit Gupta9y ago
There might be fetching null value from database. You can either use
IsNull(columnname,0);

Or
for (int a = 0; a < dataGridView1.Rows.Count; a++)
{
   var val = dataGridView1.Rows[a].Cells[2].Value;
    if(val != DBNull.Value)
         sum += Convert.ToInt32(val);
}
label5.Text= sum.ToString();
}