Question

private void btnUpdate_Click(object sender, EventArgs e)
{
    using (testEntities Setupctx = new testEntities())
    {

        var toBeUpdatedStart = txtStart.Text;
        var toBeUpdatedStop = txtStop.Text;
        shifthour updateShiftStart;
        shifthour updateShiftStop;
        updateShiftStart = Setupctx.shifthours.FirstOrDefault(u => u.shiftTiming_start == toBeUpdatedStart);
        updateShiftStop = Setupctx.shifthours.FirstOrDefault(p => p.shiftTiming_stop == toBeUpdatedStop);
        updateShiftStart.shiftTiming_start = txtStart.Text;  <-- error prompt here
        updateShiftStop.shiftTiming_stop = txtStop.Text;
        Setupctx.SaveChanges();
        txtStart.Text = "";
        txtStop.Text = "";
        MessageBox.Show("Shift Timing Has Been Updated.");
    }
}

Hi, anyone have any idea what’s wrong with this code?
More information :
This is to edit shift hours for staff. When I entered the new start and stop time, the error prompt out and say “Object reference not set to an instance of an object.”

Answer 1

private void btnUpdate_Click(object sender, EventArgs e)
{
using (testEntities Setupctx = new testEntities())
{
int ID = Int32.Parse(lblID.Text);
var SHquery = (from sh in Setupctx.shifthours
where sh.idShiftHours == ID
select sh).First();

                SHquery.shiftTiming_start = txtStart.Text;
                SHquery.shiftTiming_stop = txtStop.Text;
                Setupctx.SaveChanges();
                txtStart.Text = "";
                txtStop.Text = "";
                this.Edit_Shift_Hours_Load(null, EventArgs.Empty);
                MessageBox.Show("Shift Timing Has Been Updated.");
        }
    }