summing columns error

Irakli Lekishvili

when i use this code vs shows following error : Specified cast is not valid. with title : InvalidCastExeption was unhandled

what is incorrect i think it must be work very good. cant find any mistake

  private void TradeLog_Load_1(object sender, EventArgs e)
        {
sqlDataAdapter1.Fill(dataSet11);
decimal allwin;
            decimal win = 0;
            decimal self;

            for (int i = 0; i < DgvLog.Rows.Count; i++)
            {
                self = (decimal)DgvLog.Rows[i].Cells["selfPriceDataGridViewTextBoxColumn"].Value;
                win += self;
            }

            allwin = sum - win;
            label7.Text = win.ToString();
        }

5 Replies

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Sam Hobbs16y ago
I assume it is a DataGridView, but you should state explicitly in questions what the data is. Note that a DataGridView usually has an empty row at the bottom for adding rows and that row often is a problem in situations such as this. So you need to check to see if a row index is equal to the NewRowIndex Property, since if the index is for the new row, the values of the cells might be null, or something like that. Also, we should use try/catch more than we would like to; in this situation, you could use try/catch to catch the error and issue an error message. The error message could be a diagnostic technique to determine the specific condition causing the problem. An alternative to try/catch for situations in which we are casting sometnig is the "as" operator; it can be used to catch errors without causing the program to crash. So the following is a modified version that is less likely to crash. Note that I am typing this in without doing a compile so there could be syntax errors in the following; I hope it is close enough.
for (int i = 0; i < DgvLog.Rows.Count; i++)
{
if (i != DgvLog.NewRowIndex)
{
self = DgvLog.Rows[i].Cells["selfPriceDataGridViewTextBoxColumn"].Value as decimal;
if (self != null)
{
win += self;
}
}
}
Jure16y ago
Since it's money-type you can try this:

((System.Data.SqlTypes.SqlMoney)DvgLog...Value).ToDecimal();

But I'm really surprised that you get the same error with decimal.Parse(...), since there is no casting involved, and even if you have forgotten to remove the "(decimal)" cast, it shouldn't throw a casting exception.
Irakli Lekishvili16y ago
Suthish Nair
it does not work also. self price in sql table is type of money
Jure Ziberna
that code gets same error .it is money type

I use code like that another column and its work fine.
Jure16y ago
It's not null, but cast exception, so I think it's just a matter of casting.

What type is DgvLog...Value? You probably just need to parse it -> decimal.Parse(DgvLog...Value)

Suthish Nair16y ago

try..

        if (DgvLog.Rows.Count > 0)
        {
            for (int i = 0; i < DgvLog.Rows.Count; i++)
            {

                self = (DgvLog.Rows[i].Cells["selfPriceDataGridViewTextBoxColumn"].Value == null ? 0 : (decimal)DgvLog.Rows[i].Cells["selfPriceDataGridViewTextBoxColumn"].Value);
                win += self;
            }
            allwin = sum - win; 
            label7.Text = win.ToString();
        }

if using TextBox control, then use FindControl method to find the control.