Delphi XE ListBox实现伸缩效果
功能:实现年月日压缩,初始化时item是所有年,点击年展开月,点击月展开天,再点击则收缩。
思路:实际上一开始是将所有item显示,只是将月日的item.height赋值为0,
记录每一行的item的index,包括年,月,日,
找到年的item,点击时,显示月的item,赋month.height即可,其他同理。
接下来就是处理边界值。
unit listbox_test;
interface
uses
System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,
FMX.Types, FMX.Graphics, FMX.Controls, FMX.Forms, FMX.Dialogs, FMX.StdCtrls, StrUtils,
FMX.Layouts, FMX.ListBox, FMX.Memo, FMX.Controls.Presentation, FMX.ScrollBox;
type
TListBoxFortest = class(TForm)
ListBox1: TListBox;
Layout1: TLayout;
Memo1: TMemo;
procedure FormCreate(Sender: TObject);
procedure ListBox1ItemClick(const Sender: TCustomListBox;
const Item: TListBoxItem);
private
{ Private declarations }
public
{ Public declarations }
end;
var
ListBoxFortest: TListBoxFortest;
Year : Array[ 0..2 ] Of string = ('2015', '2014', '2013' );
Month : Array[ 0..3 ] Of Integer = (1, 2, 3, 4);
Day : Array[ 0..4 ] Of Integer = (10, 11, 12, 13, 14);
YearIndex : Array of Integer ;
MonthIndex : Array of Array of Integer ; //二维
ExpandYear : Integer;
ExpandMonth : Integer;
implementation
{$R *.fmx}
procedure TListBoxFortest.FormCreate(Sender: TObject);
var
yItem : TListBoxItem;
mItem : TListBoxItem;
dItem : TListBoxItem;
iyear : integer;
imonth : integer;
iday : integer;
begin
//设置默认值
ExpandYear := -1;
ExpandMonth := -1;
//初始化长度
setlength(YearIndex, Length(Year));
setlength(MonthIndex, Length(Year), Length(Month));
with ListBox1 do begin
BeginUpdate;
for iyear := 0 to Length(Year) - 1 do begin
yItem := TListBoxItem.Create(nil);
yItem.Parent := ListBox1;
yItem.Name := 'year' + Year[iyear] ;
yItem.Text := 'year' + Year[iyear] ;
yItem.Height := 40;
YearIndex[iyear] := listbox1.Items.Count - 1;
for imonth := 0 to Length(Month) - 1 do begin
mItem := TListBoxItem.Create(nil);
mItem.Parent := ListBox1;
mItem.Name := 'month' + Month[imonth].ToString ;
mItem.Text := ' month' + Month[imonth].ToString ;
mItem.Height := 0;
MonthIndex[iyear,imonth] := listbox1.Items.Count - 1;
for iday := 0 to Length(Day) - 1 do begin
dItem := TListBoxItem.Create(nil);
dItem.Parent := ListBox1;
dItem.Name := 'day' + Day[iday].ToString ;
dItem.Text := ' day' + Day[iday].ToString ;
dItem.Height := 0;
end;
end;
end;
EndUpdate;
end;
for iyear := 0 to Length(Year) - 1 do begin
self.Memo1.Lines.Add( 'year' + Year[iyear] + ' : ' + YearIndex[iyear].ToString);
for imonth := 0 to Length(Month) - 1 do begin
self.Memo1.Lines.Add( 'month' + Month[imonth].ToString + ' : ' + MonthIndex[iyear,imonth].ToString);
end;
end;
end;
procedure TListBoxFortest.ListBox1ItemClick(const Sender: TCustomListBox;
const Item: TListBoxItem);
var
SeletedItemName : string;
SeletedItemIndex: Integer;
EndIndex : Integer;
FindItemIndex : Integer;
SubItemIndex : Integer;
temp : Integer;
temp_1 : Integer;
begin
SeletedItemName := ListBox1.ListItems[listBox1.ItemIndex].Name; //选中的item名
SeletedItemIndex := ListBox1.ListItems[listBox1.ItemIndex].Index; //选中的item索引
if LeftStr(SeletedItemName, 4) = 'year' then
begin
for FindItemIndex:=0 to Length(YearIndex) - 1 do
begin
if YearIndex[FindItemIndex] = SeletedItemIndex then //年的索引
break;
end;
if ListBox1.ListItems[SeletedItemIndex + 1].Height = 30 then
ExpandYear := FindItemIndex
else
ExpandYear := -1;
if ExpandYear <> -1 then
begin
if FindItemIndex = Length(YearIndex) - 1 then
EndIndex := ListBox1.Items.Count - 1
else
EndIndex := YearIndex[FindItemIndex + 1] - 1;
with ListBox1 do begin
BeginUpdate;
for SubItemIndex := SeletedItemIndex + 1 to EndIndex do
begin
ListBox1.ListItems[SubItemIndex].Height := 0;
ListBox1.ListItems[SubItemIndex].Visible := false;
end;
EndUpdate;
end;
ExpandYear := -1;
end
else
begin
temp := Length(MonthIndex[FindItemIndex]); // 选中的该年 月索引的个数
with ListBox1 do begin
BeginUpdate;
for SubItemIndex := 0 to temp - 1 do
begin
temp_1 := MonthIndex[FindItemIndex,SubItemIndex]; // 遍历选中的Item下一级(月)的每个itemindex
ListBox1.ListItems[temp_1].Height := 30;
ListBox1.ListItems[temp_1].Visible := true;
end;
ExpandYear := FindItemIndex; // 展开年的ItemIndex
EndUpdate;
end;
end;
end;
for temp := 0 to Length(Year) - 1 do
for temp_1 := 0 to Length(Month) - 1 do
if SeletedItemIndex = MonthIndex[temp,temp_1] then begin
ExpandYear := temp; // 展开的年itemindex
break;
end;
if (LeftStr(SeletedItemName,5) = 'month') and (ExpandYear <> -1) then
begin
temp := Length(MonthIndex[ExpandYear]);
for FindItemIndex := 0 to temp - 1 do
begin
if MonthIndex[ExpandYear, FindItemIndex] = SeletedItemIndex then // 展开的月itemindex
break;
end;
if ListBox1.ListItems[SeletedItemIndex + 1].Height = 30 then
ExpandMonth := FindItemIndex
else
ExpandMonth := -1;
if FindItemIndex <> temp -1 then // 处理边界值
EndIndex := MonthIndex[ExpandYear, FindItemIndex + 1] - 1 // 该月中天的最后索引
else begin
if ExpandYear <> Length(Year) - 1 then
EndIndex := YearIndex[ExpandYear + 1] - 1
else
EndIndex := listBox1.Items.Count - 1;
end;
// 天的索引为月点击(SubItemIndex)MItemIndex+1 - 下一个(EndIndex)MItemIndex + 1 之间的索引
with ListBox1 do
begin
BeginUpdate;
for SubItemIndex := MonthIndex[ExpandYear, FindItemIndex] + 1 to EndIndex do // 将该月的下一级从第一个到最后一个遍历显示
begin
if ExpandMonth = -1 then
begin
ListBox1.ListItems[SubItemIndex].Height := 30;
ListBox1.ListItems[SubItemIndex].Visible := true;
end
else
begin
ListBox1.ListItems[SubItemIndex].Height := 0;
ListBox1.ListItems[SubItemIndex].Visible := false;
end;
end;
if ExpandMonth = -1 then
ExpandMonth := FindItemIndex
else
ExpandMonth := -1;
EndUpdate;
end;
end;
end;
end.