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Basic functions of the listbox explained (Views: 101)


Problem/Question/Abstract:

I'm a beginner, how do i use the listbox??

Answer:

Ok heres some basic info on the listbox.
Their are many different functions to do with the listbox and it is not possible to display them all. So i am going to try and explain as many as possible.

Number 1, Lets start from the beginning.

OK so once you have placed the listbox you can add items at design time but to add them at runtime is a little more trick

make a form with one listbox, 1 button and 1 edit box

then add the following

in the button1 onclick method plave

listbox1.items.add(edit1.text);

this then adds the current text in the edit box onto the bottom of the list you can add as many items as you like until you exit the program.

Number 2, Taking it one step further.

Ok so you have a listbox now with a few items in it, but what if you want to add one of the items in at say line 3 instead of the bottom line. This can easily be achieved by amending the above code, by changing the 'add' to 'insert' and then adding an index refrence you can place it in at the desired line.

for example

listbox1.items.insert(3, edit1.text);

this will always then add the text from the edit box to the third line

Number 3, The rest.

Ok now you can get the total amount of items currently in a listbox by inserting the count procedure

showmessage('Current Number of lines := ' + inttostr(listbox1.items.count));

this will then display the message 'Current Number of Lines := ??' where ?? is a number.

Finally to get the currently selected item in the listbox you can add the following to the onclick method of your listbox

edit1.text := listbox1.items[listbox1.itemindex];

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