Listbox.Clear .Add Methods

Much like in VB, I figured I would need to create some fancy listbox functions for C++.


Here is one I cannot seem to get to work properly.

PHP Code:

---

//------------------
//Add an item to the list
//------------------
void ListBox::AddItem(char* Item)
{
    //add string
    SendMessage(m_hwnd, LB_ADDSTRING, 0, (LPARAM)Item);
    SendMessage(m_hwnd, LB_SETITEMDATA, m_IndexCount, (LPARAM)m_IndexCount);
    m_IndexCount++;
}


//------------------
//Clear the entire list
//------------------
void ListBox::Clear()
{
    LRESULT lRet;
    for (int Index = 0; Index < m_IndexCount+1; Index++)
    {
        lRet = SendMessage(m_hwnd, LB_DELETESTRING, Index,0);
    }

    m_IndexCount = 0;
} 


---

So I add a bunch of strings using the Add function, then I try and clear it all.

Well now and then it clears all but one, sometimes all but two depending on how many I add. If it clears all but 1 or 2, or more..then I can just keep pressing it and it gets rid of everything one at a time.

What is going on????

Instead of sending an LB_DELETESTRING message for each item, just send an LB_RESETCONTENT message.

You know, I scoured the list of messages, styles, notifications on MSDN for something like that and I just didn't see it.

Thank you, it all works fine now.

RemoveItem, AddItem, Clear...all work

Index is always 0...it never incrememnts, shouldnt it?
MSDN says that particular SendMessage returns the index of the added string.

PHP Code:

---

//------------------
//Add an item to the list
//------------------
void ListBox::AddItem(char* Item)
{
    int Index=0;
    //add string
    Index = SendMessage(m_hwnd, LB_ADDSTRING, 0, (LPARAM)Item);
    SendMessage(m_hwnd, LB_SETITEMDATA, Index, (LPARAM)Item);
} 


---

Why are you adding an item to the list and then setting the text of the item again? The string would be there after LB_ADDSTRING.

Are you subclassing? That may be why it returns 0.

Yes I am subclassing, and it was the reason, fixed that part.

Now wuts wrong the above, I do see setting the string twice...thats just how I saw some code do it so each item had a proper index.

I guess though I don't really need any item data I found ways around all of that already.