Gridview checkbox is giving object cannot be cast from dbnull to other types if check box is not checked C#

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Hi im using the following code to copy a gridview dataschema and checked rows to a separate table.
It works very fine when all the rows are checked. but giving an error

object cannot be cast from dbnull to other types

when i left few rows unchecked in the beginning.

Please help to solve this issue. i need to get the only checked row data into that variable.

Thanks in advanced...

What I have tried:

var bindingsource = (BindingSource)dgv_summary.DataSource;
                DataTable tbl = ((DataTable)bindingsource.DataSource).Clone();
                var rows = dgv_summary.Rows.OfType<DataGridViewRow>()
                                        .Where(r => Convert.ToBoolean(r.Cells[" "].Value))
                                        .Select(r => ((DataRowView)r.DataBoundItem).Row);
                foreach (var row in rows)
                {
                    tbl.ImportRow(row);
                }
                DataTable dt_Cust = tbl.DefaultView.ToTable(true, "GL_ACNO");

Posted 17-Jan-18 1:28am

chaitanya556

Updated 17-Jan-18 17:57pm

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2 solutions

Solution 1

Most likely it is the statement:

C#

r => Convert.ToBoolean(r.Cells[" "].Value)

If it is dbnull then it cannot be converted to boolean as it has no implicit value. You need to add some code to ignore rows with dbnull entries.

Posted 17-Jan-18 2:23am

Richard MacCutchan

Comments

chaitanya556 17-Jan-18 22:36pm

ya i know that.. im looking for some code suggestions. if you can suggest me some code to ignore the rows with null values in the above code.

Thank you

Richard MacCutchan 18-Jan-18 5:17am

Just check the value to see if it is dbnull.

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Karthik_Mahalingam · Accepted Answer · 2018-01-17T17:57:00

try casting in a method

var rows = dgv_summary.Rows.OfType<DataGridViewRow>()
                                   .Where(r =>  GetBoolValue( r.Cells[" "].Value))
                                   .Select(r => ((DataRowView)r.DataBoundItem).Row);

private bool GetBoolValue(object value) {
        string val = Convert.ToString(value);
        bool returnValue ;
        Boolean.TryParse(val, out returnValue);
        return returnValue;
    }