RAD Studio VCL Reference
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Specifies the index number of the item that appears at the top of the list box.
property TopIndex: Integer;
__property int TopIndex;
Use TopIndex property to find or set the first item displayed at the top of the list box. TopIndex can be used, for example, to change the topmost item to a different item in the list.
C++ Examples:
/* The following example uses a list box containing a list of strings, a button, and an edit box on a form. When the user runs the application and clicks the button, the third item in the list becomes the first item, and the index value of that item appears in the edit box. The index value displayed is 2, indicating the third item in the list (the first item in the list has an index value of 0): */ void __fastcall TForm1::Button1Click(TObject *Sender) { ListBox1->TopIndex = 2; Edit1->Text = IntToStr(ListBox1->TopIndex); } void __fastcall TForm1::FormCreate(TObject *Sender) { for (int Number = 1; Number <= 20; Number++) ListBox1->Items->Add("Item " + IntToStr(Number)); }
Delphi Examples:
{ The following example uses a list box containing a list of strings, a button, and an edit box on a form. When the user runs the application and clicks the button, the third item in the list becomes the first item, and the index value of that item appears in the edit box. The index value displayed is 2, indicating the third item in the list (the first item in the list has an index value of 0): } procedure TForm1.Button1Click(Sender: TObject); begin ListBox1.TopIndex := 2; Edit1.Text := IntToStr(ListBox1.TopIndex); end; procedure TForm1.FormCreate(Sender: TObject); var Number: Integer; begin for Number := 1 to 20 do ListBox1.Items.Add('Item ' + IntToStr(Number)); end;
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