RAD Studio VCL Reference
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Occurs when the user clicks on a column header in a list view.
property OnColumnClick: TLVColumnClickEvent;
__property TLVColumnClickEvent OnColumnClick;
Write an OnColumnClick event handler to respond to clicks made in the column header when ViewStyle is vsReport. The Column parameter is the TListColumn object from the Columns property that describes the column that was clicked.
OnColumnClick only occurs when ViewStyle is vsReport and ShowColumnHeaders is true.
C++ Examples:
/* This example shows how to use the OnColumnClick and OnCompare events of a list view to let users sort the columns 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. The OnColumnClick event handler sets the global variable to indicate the column to sort and calls AlphaSort: */ void __fastcall TForm1::FormCreate(TObject *Sender) { TListItem *Item; TListColumn *Column; const char imagenames[3][20] = { "C++ Image", "Borland Image", "Delphi Image"}; const char Col2Array[3][40] = { "Documentation for the C++ icon.", "Borland icon.", "Delphi icon." }; // Create a ListView item for each image in the ImageList ListView1->SmallImages = ImageList1; ListView1->LargeImages = ImageList1; for (int i = 0; i < ImageList1->Count; i++) { Item = ListView1->Items->Add(); Item->Caption = imagenames[i]; Item->ImageIndex = i; Item->SubItems->Add(Col2Array[i]); } // Create two columns to show during viewing as vsReport Column = ListView1->Columns->Add(); Column->Caption = "Column 1"; Column->Width = 200; Column = ListView1->Columns->Add(); Column->Caption = "Column 2"; Column->Width = 200; ListView1->ViewStyle = vsReport; } int ColumnToSort = 0; /* The OnColumnClick event handler sets the global variable to indicate the column to sort and calls AlphaSort: */ void __fastcall TForm1::ListView1ColumnClick(TObject *Sender, TListColumn *Column) { ColumnToSort = Column->Index; ((TCustomListView *)Sender)->AlphaSort(); } /* The OnCompare event handler causes the list view to sort on the selected column: */ void __fastcall TForm1::ListView1Compare(TObject *Sender, TListItem *Item1, TListItem *Item2, int Data, int &Compare) { if (ColumnToSort == 0) Compare = CompareText(Item1->Caption,Item2->Caption); else { int ix = ColumnToSort - 1; Compare = CompareText(Item1->SubItems->Strings[ix], Item2->SubItems->Strings[ix]); } }
Delphi Examples:
{ This example shows how to use the OnColumnClick and OnCompare events of a list view to let users sort the columns 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. The OnColumnClick event handler sets the global variable to indicate the column to sort and calls AlphaSort: } var ColumnToSort: Integer; procedure TForm1.FormCreate(Sender: TObject); var I: Integer; ListItem: TListItem; NewColumn: TListColumn; const imagenames: Array[0..2] of string = ('C++ Image', 'Borland Image', 'Delphi Image'); begin Col2Array[0]:= 'Documentation for the C++ icon.'; Col2Array[1]:= 'Borland icon.'; Col2Array[2]:= 'Delphi icon.'; // Create a ListView item for each image in the ImageList with ListView1 do begin SmallImages := ImageList1; LargeImages := ImageList1; for I := 0 to ImageList1.Count - 1 do begin ListItem := Items.Add; Listitem.Caption := imagenames[I]; ListItem.ImageIndex := I; Listitem.SubItems.Add(Col2Array[I]); end; // Create two columns to show during viewing as vsReport NewColumn := Columns.Add; NewColumn.Caption := 'Column 1'; NewColumn.Width := 200; NewColumn := Columns.Add; NewColumn.Caption := 'Column 2'; NewColumn.Width := 200; ListView1.ViewStyle := vsReport; end; end; procedure TForm1.ListView1ColumnClick(Sender: TObject; Column: TListColumn); begin ColumnToSort := Column.Index; (Sender as TCustomListView).AlphaSort; end; { The OnCompare event handler causes the list view to sort on the selected column: } procedure TForm1.ListView1Compare(Sender: TObject; Item1, Item2: TListItem; Data: Integer; var Compare: Integer); var ix: Integer; begin if ColumnToSort = 0 then Compare := CompareText(Item1.Caption,Item2.Caption) else begin ix := ColumnToSort - 1; Compare := CompareText(Item1.SubItems[ix],Item2.SubItems[ix]); end; end; { Note: This OnCompare event handler uses the global CompareText function. An application may want to use AnsiCompareText, CompareStr, or AnsiCompareStr instead, depending on whether the comparison should be case-sensitive and whether the locale should be considered. }
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