how to select on the valid listview items?

**mark103** · 05-03-2012

Hi guys,

Can you please help me with my listview items. I want to know that when a user select the items on the listview to tick and untick on the checkboxes while a user do not select on the other listview items, how do the program suppose to know which listview items that a user have selected after tick and untick on the checkboxes?

Something like this:

Code:

for each (ListViewItem ^checkeditems in listView1::SelectedItems)
{
	if (checkeditems->Selected == true)
	{
	 if (checkeditems->Checked == true)
	 {
		checkeditems->Selected = false;
	 }
	 else if (checkeditems->Checked == false)
	 {
		MessageBox::Show(checkeditems->SubItems[1]->Text);
	 }
	}
}

I need to know how to do this because I want to send the information of substring text to my php server.

If you know how i can do this, I would be very grateful.

Thanks,
Mark

**Neo1** · 05-03-2012

Code:

(checkeditems->Selected == true)

Whenever you write "== true", god kills a sweet innocent kitten. You monster!

Seriously though, nobody has even the slightest chance of helping you unless you tell us what GUI framework this is.

**Subsonics** · 05-04-2012

Originally Posted by Neo1

Whenever you write "== true", god kills a sweet innocent kitten. You monster!

If checkeditems->Selected is declared as "bool" that seems perfectly reasonable IMO.

**Neo1** · 05-04-2012

Originally Posted by Subsonics

If checkeditems->Selected is declared as "bool" that seems perfectly reasonable IMO.

No, "== true" is never reasonable.

Code:

(checkeditems->Selected == true)

Is equivalent to:

Code:

(checkeditems->Selected)

Writing "== true" is basically just another way of saying "i don't know how boolean-expressions work".

**Elkvis** · 05-04-2012

Originally Posted by Neo1

another way of saying "i don't know how boolean-expressions work".

if it's a nullable bool, then "== true" is a perfectly valid expression, because System::Nullable<bool> doesn't implicitly convert to bool, but it does have an overloaded equality operator.

**Neo1** · 05-04-2012

Originally Posted by Elkvis

if it's a nullable bool, then "== true" is a perfectly valid expression, because System::Nullable<bool> doesn't implicitly convert to bool, but it does have an overloaded equality operator.

What's your point? The code in question is pseudo-code, we obviously aren't talking about nullables or tribools or whatever. My point still stands, using "== true" in a boolean expression is fundamentally wrong. You found an exception to this rule, have some cake.

**Subsonics** · 05-04-2012

Originally Posted by Neo1

No, "== true" is never reasonable.

Code:

(checkeditems->Selected == true)

Is equivalent to:

Code:

(checkeditems->Selected)

Writing "== true" is basically just another way of saying "i don't know how boolean-expressions work".

So what, it comes down to opinion. You don't think it's reasonable because there is an equivalent short hand available, it's nothing wrong with explicitly typing it out. The short hand buys you nothing.

**ZuK** · 05-04-2012

i prefer

Code:

(! checkeditems->Selected != true)

just to make people wonder

Kurt

**Neo1** · 05-06-2012

Originally Posted by Subsonics

So what, it comes down to opinion. You don't think it's reasonable because there is an equivalent short hand available, it's nothing wrong with explicitly typing it out. The short hand buys you nothing.

Wrong, my version is not shorthand for anything. There is something wrong with writing out " == true", if your expression evaluates to true, you don't then have to compare it to true, that's not the right way, that's stupid.

You're essentially asking your computer to compare true to true, or true to false.

The short hand buys you nothing.

How does "true == true" buy you anything?

Do you also write:

Code:

if( x > 5 == true)

And would you consider:

Code:

if(x > 5)

..to be short hand?

**Subsonics** · 05-06-2012

What is extremely poor, redundant etc. will vary depending on who you ask.

**Neo1** · 05-06-2012

Originally Posted by Subsonics

What is extremely poor, redundant etc. will vary depending on who you ask.

Boolean algebra is extremely well-defined, and you will find it is possible to mathematically prove what is redundant and what is not.

Fortunately, writing code is a science, more than it is an art.

**Subsonics** · 05-06-2012

Originally Posted by Neo1

Boolean algebra is extremely well-defined, and you will find it is possible to mathematically prove what is redundant and what is not.

So what, C is not boolean algebra. What about descriptive variable and function names, or comments. Redundant?

**Neo1** · 05-06-2012

Originally Posted by Subsonics

So what, C is not boolean algebra. What about descriptive variable and function names, or comments. Redundant?

Hey man, you're the one defending the use of an extra comparison for purposes of styling. I'm all for descriptive names. Anything else would be wrong.

**Subsonics** · 05-06-2012

Originally Posted by Neo1

Hey man, you're the one defending the use of an extra comparison for purposes of styling. I'm all for descriptive names. Anything else would be wrong.

Writing out "== true" does not result in a extra comparison. The comparison is made anyway but implicitly.

**Elkvis** · 05-06-2012

how is any of this related to the OP's question?

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