Alert me why are the results changing every other call?

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here we using if statement and it's work fine for first time

then when i enter barcode and pressed enter again it's going direct to else statement it's mean shown me error message under as we see on else statement and i think it's not repeat whole statement as new process because i'm sure from condition it's true and it shouldn't go to else statement but in third time when i try enter barcode and check from condition it's work fine like first time and then in forth time show me error again

why error message shown on every second try

 block is this line:

C#

<pre>if (dt.Rows.Count > 0)

here whole code

C#

<pre>private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
    if (e.KeyCode == Keys.Enter)
    {
        if (checkBox1.Checked)
        {

            if (qtystate == true)
            {
                DataTable dt;
                barcode = textBox1.Text;
                dt = pro.GetProdcutBar(textBox1.Text);

                if (dt.Rows.Count > 0)
                {
                    foreach (DataRow row in dt.Rows)
                    {
                        barcode = row[0].ToString();
                        itemno = row[1].ToString();
                        itemname = row[2].ToString();
                        salespric = row[3].ToString();
                        costprice = row[4].ToString();
                    }
                    cont.addprodcuttocount(Convert.ToString(barcode), Convert.ToString(itemno), Convert.ToString(itemname),
                        Convert.ToString(salespric), Convert.ToString(costprice), "1", DateTime.Now, SystemInformation.ComputerName);
                    refershgridview();

                    //sum qty
                    try
                    {
                        int sum = 0;
                        for (int i = 0; i < dataGridView1.Rows.Count; ++i)
                        {
                            if (Convert.ToString(dataGridView1.Rows[i].Cells[1].Value) == textBox1.Text)
                            {
                                sum += Convert.ToInt32(dataGridView1.Rows[i].Cells[6].Value);
                            }

                        }
                        label3.Text = "Barcode " + barcode + " - " + "Item NO" + itemno + " - " + "item name " + itemname + " - " + "qty  " + sum.ToString();
                    }

                    catch
                    {

                    }

                    barcode = "";
                    itemno = "";
                    itemname = "";
                    salespric = "";
                    costprice = "";
                    qtyitem = "";
                    textBox1.Clear();
                    textBox1.Focus();
                }

                else
                {
                    MessageBox.Show("00barcode not found", "barcode", MessageBoxButtons.OK, MessageBoxIcon.Stop);
                    barcode = "";
                    itemno = "";
                    itemname = "";
                    salespric = "";
                    costprice = "";
                    qtyitem = "";
                    textBox1.Clear();
                    textBox1.Focus();
                }

            }

        }

    }
}

What I have tried:

i try to remove try blocks and nothing happens

Posted 7-Nov-18 0:05am

mohammed mqi

Updated 7-Nov-18 0:17am

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Comments

F-ES Sitecore 7-Nov-18 6:10am

Use the debugger to step through your code to see what is happening.

mohammed mqi 7-Nov-18 7:04am

when i debug my code it's give me one result

Richard MacCutchan 7-Nov-18 8:27am

Why are you using Convert.ToString on all the items that have previously been returned in string form? Also you set barcode equal to textBox1.Text, but then use that same text to create your datatable.

mohammed mqi 7-Nov-18 9:05am

thanks Richard for replay i'm using Convert.ToString to be more insure and becuase some time i revived float value
and about barcode equal to textBox1.Text becuase i'm using textBox1.Text for manual to put qty manul in other case after receiving barcode first then if qty empty it will be pass qty from textBox1.Text when switch case to inserting qty

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OriginalGriff · Answer 1 · 2018-11-07T00:17:00

We can't tell you, because we don't know exactly what you are doing, where the barcode info is going, ... and we can't run your code to find out (we don't have your scanner, your pro class, or any idea what it's GetProdcutBar method is doing.

So, it's going to be up to you.
Fortunately, you have a tool available to you which will help you find out what is going on: the debugger - a quick Google for "Visual Studio debugger" should give you the info you need to get started with it.

Put a breakpoint on the first line in the function, and run your code through the debugger. Then look at your code, and at your data and work out what should happen manually. Then single step each line checking that what you expected to happen is exactly what did. When it isn't, that's when you have a problem, and you can back-track (or run it again and look more closely) to find out why.

Sorry, but we can't do that for you - time for you to learn a new (and very, very useful) skill: debugging!

But before you do that, stop swallowing exceptions!
When you write code like this:

try
{
    int sum = 0;
    for (int i = 0; i < dataGridView1.Rows.Count; ++i)
    ...
}

catch
{

}

The chances are that you are throwing away information you really do need in order to fix problems. Either don't use a try...catch block at all, or use the Exception object to help you fix problems: log it, show it to the user, output it to the debug console, whatever - but just catching everything and ignoring it means you don't even know that a problem has happened until it shows up as a problem elsewhere, or elsewhen...