Raz-Soft

Here is how you can use the OnColumnClick and OnCompare events of a TListView to let users sort the columns (ascending/descending) in a report-style list view by clicking on the column headers. This requires a global variable to keep track of the column that was clicked:

[cpp]

int ColumnToSort; // add this global var in the private section of your TForm1 Class….

//—————————————————————————

void __fastcall TForm1::ListView1ColumnClick(TObject *Sender,
TListColumn *Column)
{

ColumnToSort = Column->Index;
ListView1->AlphaSort(); //trigger ListView1Compare

if (ColumnToSort==0)
ListView1->Tag=(ListView1->Tag==1) ? 0:1 ;
else
ListView1->Columns->Items[ColumnToSort-1]->Tag=(ListView1->Columns->Items[ColumnToSort-1]->Tag==1) ? 0:1;

}
//—————————————————————————

void __fastcall TForm1::ListView1Compare(TObject *Sender, TListItem *Item1,
TListItem *Item2, int Data, int &Compare)
{
AnsiString Str1,Str2;
int ColTag;

if (ColumnToSort == 0)
{
ColTag=ListView1->Tag;
Str1=Item1->Caption;
Str2=Item2->Caption;
}
else
{
ColTag=ListView1->Columns->Items[ColumnToSort-1]->Tag;
Str1=Item1->SubItems->Strings[ColumnToSort-1];
Str2=Item2->SubItems->Strings[ColumnToSort-1];
}

if (ColTag==1)
Compare=CompareText(Str1,Str2);
else
Compare=CompareText(Str2,Str1);

}
//—————————————————————————
[/cpp]

Add some items to your list and test it. Clicking on the same column will switch between ascending and descending sort:
[cpp]
void __fastcall TForm1::FormCreate(TObject *Sender)
{
ColumnToSort=0;
//add some items to test ListView sorting…
TListItem *tli=ListView1->Items->Add();
tli->Caption=”A item “;
tli->SubItems->Add(“B subitem1″);
tli->SubItems->Add(“C subitem2″);

tli=ListView1->Items->Add();
tli->Caption=”B item “;
tli->SubItems->Add(“E subitem1″);
tli->SubItems->Add(“A subitem2″);

tli=ListView1->Items->Add();
tli->Caption=”C item “;
tli->SubItems->Add(“A subitem1″);
tli->SubItems->Add(“E subitem2″);

tli=ListView1->Items->Add();
tli->Caption=”D item “;
tli->SubItems->Add(“C subitem1″);
tli->SubItems->Add(“D subitem2″);

tli=ListView1->Items->Add();
tli->Caption=”E item “;
tli->SubItems->Add(“D subitem1″);
tli->SubItems->Add(“B subitem2″);
}
[/cpp]