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   <TITLE>Add items to a ListView from code at runtime.</TITLE>

   <META NAME="Author" CONTENT="Harold Howe">

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<H3>

Add items to a ListView from code at runtime.

</H3>

<P>

The <TT>ListView</TT> control provides a nice interface for adding

items at design time from the IDE. However, you will usually need to

fill in the <TT>ListView</TT> based on runtime information. This code snippet

shows how to create <TT>ListView</TT> items and subitems from code.

</P>

<pre>

    <b>int</b> NumEntries <b>=</b> <font color="blue">20</font><b>;</b>

    TListItem <b>*</b>NewEntry<b>;</b>

    ListView1<b>-></b>Items<b>-></b>BeginUpdate<b>(</b><b>)</b><b>;</b>

    ListView1<b>-></b>Items<b>-></b>Clear<b>(</b><b>)</b><b>;</b>

    <b>for</b> <b>(</b><b>int</b> j<b>=</b><font color="blue">0</font><b>;</b> j &lt; NumEntries<b>;</b> j<b>++</b><b>)</b>

    <b>{</b>

        NewEntry <b>=</b> ListView1<b>-></b>Items<b>-></b>Add<b>(</b><b>)</b><b>;</b>

        NewEntry<b>-></b>Caption <b>=</b> <font color="blue">"Item "</font> <b>+</b> IntToStr<b>(</b>j<b>)</b><b>;</b>

        NewEntry<b>-></b>SubItems<b>-></b>Add<b>(</b><font color="blue">"column 2"</font><b>)</b><b>;</b>

        NewEntry<b>-></b>SubItems<b>-></b>Add<b>(</b><font color="blue">"column 3"</font><b>)</b><b>;</b>

        <font color="navy">// NewEntry->ImageIndex = j;         // requires an imagelist</font>

    <b>}</b>

    ListView1<b>-></b>Items<b>-></b>EndUpdate<b>(</b><b>)</b><b>;</b>

</pre>

<P>

<B>Note:</B> The <TT>BeginUpdate</TT> function prevents the <TT>ListView</TT> from

flickering as the items are added. Both <TT>TListBox</TT> and

<TT>TListView</TT> provide a <TT>BeginUpdate</TT> function that you can call to keep the

control from flashing as you manipulate the control's contents. The <TT>EndUpdate</TT>

call signals that you have finished altering the control and that the control should now

paint itself.

</P>

<P>

<B>Note:</B> Notice that you obtain the <TT>TListItem</TT> pointer by calling the <TT>Add</TT>

function, rather than calling <TT>new</TT> directly.

</P>

<P>

<B>Note: </B> Also notice that you change the characteristics of the new item after calling

the <TT>Add</TT> function.

</P>

<P>

<B>Note: </B> The <TT>Caption</TT> string appears next to the item's icon, and will always

appear regardless of the <TT>ViewStyle</TT> setting of the <TT>ListView</TT>. The

<TT>SubItems</TT> appear in separate columns when <TT>ViewStyle</TT> is set to

<TT>vsReport</TT>. For other modes, the <TT>SubItems</TT> are invisible.

</P>                    



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