Unchecked checkbox = textbox with value 0

Question

I have this code:

for (int i = 0; i < ListView2.Items.Count; i++)
{
    int a;
    Int32.TryParse(((TextBox)ListView2.Items[i].FindControl("BrankyTextBox")).ToString(), out a);

    if (((CheckBox)ListView2.Items[i].FindControl("UcastCheckBox")).Checked=false &&
         a > 0)
    {
RegisterStartupScript("alertBox2", "<script type='text/javascript'>alert('Error');</script>");
    }
}

I want to when checkbox is unchecked the value of textbox must be only 0. But this code only changes all checkbox in listview to unchecked... Have you some idea how to solve it?

`if (((CheckBox)ListView2.Items[i].FindControl("UcastCheckBox")).Checked=false || a > 0)` You're setting `Checked = false` instead of checking `Checked == false` — Nolonar, Jun 19 '13 at 11:08

DonBoitnott · Accepted Answer · 2013-06-19T11:33:17.760

3

You could clean this up a bit while you're at it:

for (Int32 i = 0; i < ListView2.Items.Count; i++)
{
    Int32 a;
    Int32.TryParse(((TextBox)ListView2.Items[i].FindControl("BrankyTextBox")).Text, out a);

    if (!((CheckBox)ListView2.Items[i].FindControl("UcastCheckBox")).Checked && a > 0)
    {
        RegisterStartupScript("alertBox2", "<script type='text/javascript'>alert('Error');</script>");
    }
}

In other words, use the not operator, which is !, to signify an inverse test. myVariable == false is equivalent to writing simply !myVariable.

edited Jun 19 '13 at 11:33

answered Jun 19 '13 at 11:12

DonBoitnott

10,787
6
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It run, but when I give && on place || it isn´t run :/ – Kate Jun 19 '13 at 11:27
Is it possible that the value in `BrankyTextBox` is not just a number (something that can parse cleanly to an `Int32`)? Or that it's parsing to zero? – DonBoitnott Jun 19 '13 at 11:31
1

Look at my edit where I replaced the `.ToString()` call with `.Text`. Is that right? – DonBoitnott Jun 19 '13 at 11:33

score 1 · Answer 2 · answered Jun 19 '13 at 11:08

1

You had only one = instead of == for comparison.

if (((CheckBox)ListView2.Items[i].FindControl("UcastCheckBox")).Checked == false || a > 0)
{
    RegisterStartupScript("alertBox2", "<script type='text/javascript'>alert('Error');</script>");
}

answered Jun 19 '13 at 11:08

gzaxx

17,312
2
36
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Yes, a have error in first post...i have OR and i must have AND – Kate Jun 19 '13 at 11:14
but when a give && it not run :/ – Kate Jun 19 '13 at 11:19
It run, but when I give && on place || it isn´t run :/ – Kate Jun 19 '13 at 11:27

score 1 · Answer 3 · answered Jun 19 '13 at 11:08

1

You assign a value of true to the checkboxes in the if statement. You need to use a double =. Like this:

if (((CheckBox)ListView2.Items[i].FindControl("UcastCheckBox")).Checked==false ||
     a > 0)

answered Jun 19 '13 at 11:08

Romano Zumbé

7,893
4
33
55

It run, but when I give && on place || it isn´t run :/ – Kate Jun 19 '13 at 11:28
Do you get an error message? If not please set a breakpoint after the try parse and check if the value of a is as ecxpected. – Romano Zumbé Jun 19 '13 at 11:37
As adition you need to change the ToString to Text: `int32.TryParse(((TextBox)ListView2.Items[i].FindControl("BrankyTextBox")).Text, out a);` – Romano Zumbé Jun 19 '13 at 11:40

score 1 · Answer 4 · edited May 23 '17 at 10:26

Your if is not doing what you expect

    if (((CheckBox)ListView2.Items[i].FindControl("UcastCheckBox")).Checked=false 
       || a > 0)

You're assigning false to the Checked property, and this statement is always false. Currently, your if could be rewritten to be

if (false || a > 0)

Which is obviously not what you want. Add an = sign, making it

if (((CheckBox)ListView2.Items[i].FindControl("UcastCheckBox")).Checked == false 
      || a > 0)

To fix the conditional expression. Another suggestion here would be to swap the conditions, benefiting from logical short-ciruiting:

if (a > 0 || ((CheckBox)ListView2.Items[i].FindControl("UcastCheckBox")).Checked == false)

In this case, when a > 0 is true the other conditions won't be evaluated resulting in (slightly!) better performance. See this other question for the details about short-circuiting.

It run, but when I give && on place || it isn´t run :/ – Kate Jun 19 '13 at 11:26 — Kate, Jun 19 '13 at 11:26

Unchecked checkbox = textbox with value 0

4 Answers4