Delphi 是否可以将VirtualStringTree用于主详图栅格视图?
好吧,我这里有件很棘手的事。。。 我想绘制/使用ChildNode的标题。 我认为这个想法是合理的,因为在子节点中有头这样子节点就可以在表中指定。 是否有VST拥有的功能,或者根本不可能 谢谢你的帮助。1。有没有办法将VirtualTreeView用于主/明细网格视图? 不,目前没有这样的功能可用,IMHO也不会,因为这将涉及对现有代码的很大干预 2。如何为子节点详细信息网格视图创建功能齐全的标题? 考虑到一些方法,如何模拟子节点的标题外观和行为,我发现将嵌套树视图用于详图网格视图非常有用。这为您带来了细节数据的独立性,并允许您将嵌套树视图定位到子节点矩形中的整个模拟最小化 2.1。启动项目 在下面的项目中,我试图展示实现如此简单的任务有多复杂,比如在子节点中定位控件(不涉及原始VirtualTree代码)。将其视为一个启动项目,而不是最终解决方案 2.2。已知问题和限制:Delphi 是否可以将VirtualStringTree用于主详图栅格视图?,delphi,delphi-7,virtualtreeview,tvirtualstringtree,Delphi,Delphi 7,Virtualtreeview,Tvirtualstringtree,好吧,我这里有件很棘手的事。。。 我想绘制/使用ChildNode的标题。 我认为这个想法是合理的,因为在子节点中有头这样子节点就可以在表中指定。 是否有VST拥有的功能,或者根本不可能 谢谢你的帮助。1。有没有办法将VirtualTreeView用于主/明细网格视图? 不,目前没有这样的功能可用,IMHO也不会,因为这将涉及对现有代码的很大干预 2。如何为子节点详细信息网格视图创建功能齐全的标题? 考虑到一些方法,如何模拟子节点的标题外观和行为,我发现将嵌套树视图用于详图网格视图非常有用。这为
- 这个项目是为了每个根节点只使用一个子节点而编写和测试的,所以当您超过这个限制时,不要对行为感到惊讶,因为这不是为您设计的,甚至不是为您测试的
- 当双击主树的列调整大小设置列调整大小的动画时,当ScrollDC函数滚动画布时,嵌套的树视图会被线条覆盖
- 为了保持VirtualTree代码不变,我已经覆盖了滚动条更新的方法。每当需要更新滚动条时,它用于更新嵌套的树视图边界
- 当前的
实现在范围和滚动位置固定之前触发事件,这使得代码更加复杂,并且有一个很大的缺点-在显示树后更新细节树视图的边界,这有时是可见的OnExpanded
单元1;
接口
使用
窗口、消息、系统工具、变体、类、图形、控件、窗体、,
对话框、stdctrl、虚拟树;
类型
TVTSCROLLBARSUPDATEVENT=对象的过程(发送方:TBaseVirtualTree;DoRepaint:布尔);
TVirtualStringTree=类(VirtualTrees.TVirtualStringTree)
私有的
FOnUpdateScrollBars:TVTScrollBarsUpdateEvent;
公众的
过程更新滚动条(dorepoint:Boolean);推翻
出版
更新滚动条上的属性:TVTScrollBarsUpdateEvent读取FOnUpdateScrollBars写入FOnUpdateScrollBars;
结束;
类型
PNodeSubTree=^TNodeSubTree;
TNodeSubTree=class
FChildTree:TVirtualStringTree;
结束;
类型
TForm1=类(TForm)
按钮1:t按钮;
VirtualStringTree1:TVirtualStringTree;
过程表单创建(发送方:ToObject);
程序按钮1点击(发送方:ToObject);
程序VirtualStringTree1afterAutoFit列(发送方:TVTHeader);
过程VirtualStringTree1BeforeDrawTreeLine(发送方:TBaseVirtualTree;
节点:PVirtualNode;级别:整数;变量PosX:整数);
过程VirtualStringTree1崩溃(发送方:TBaseVirtualTree;
节点:PVirtualNode);
过程VirtualStringTree1ColumnResize(发送方:TVTHeader;
列:TColumnIndex);
过程VirtualStringTree1Expanded(发送方:TBaseVirtualTree;
节点:PVirtualNode);
过程VirtualStringTree1FocusChange(发送方:TBaseVirtualTree;OldNode,
NewNode:PVirtualNode;OldColumn,NewColumn:TColumnIndex;
允许变量:布尔值);
过程VirtualStringTree1FreeNode(发送方:TBaseVirtualTree;
节点:PVirtualNode);
过程VirtualStringTree1MeasureItem(发送方:TBaseVirtualTree;
TargetCanvas:TCanvas;节点:PVirtualNode;变量NodeHeight:Integer);
私有的
过程使子树无效(树:TBaseVirtualTree);
过程重定大小子树(树:TBaseVirtualTree);
过程更新subtreebounds(树:TBaseVirtualTree;节点:PVirtualNode);
更新滚动条上的过程(发送方:TBaseVirtualTree;dorepoint:Boolean);
公众的
{公开声明}
结束;
变量
表1:TForm1;
实施
{$R*.dfm}
{TVirtualStringTree}
过程TVirtualStringTree.UpdateScrollBars(DoRepaint:Boolean);
开始
继承;
如果HandleAllocated和Assigned(FOnUpdateScrollBars),则
FOnUpdateScrollBars(Self、DoRepaint);
结束;
{TForm1}
过程TForm1.FormCreate(发送方:TObject);
开始
ReportMemoryLeaksOnShutdown:=True;
VirtualStringTree1.NodeDataSize:=SizeOf(TNodeSubTree);
VirtualStringTree1.onUpdate滚动条:=onUpdate滚动条;
结束;
程序TForm1.按钮1单击(发送方:TObject);
变量
资料:PNodeSubTree;
节点:PVirtualNode;
开始
节点:=VirtualStringTree1.AddChild(nil);
节点:=VirtualStringTree1.AddChild(节点);
VirtualStringTree1.InitNode(节点);
数据:=VirtualStringTree1.GetNodeData(节点);
数据^:=TNodeSubTree.Create;
Data^.FChildTree:=TVirtualStringTree.Create(无);
使用Data.FChildTree do
开始
可见:=假;
父节点:=VirtualStringTree1;
高度:=150;
DefaultNodeHight:=21;
Header.AutoSizeIndex:=0;
Header.Font.Charset:=默认字符集;
Header.Font.Color:=clWindowText;
Header.Font.Height:=-11;
Header.Font.Name:=“Tahoma”;
Header.Font.Style:=[];
收割台高度:=21;
Header.Options:=[hoColumnResize,hoDrag,hoShowSortGlyphs,hoVisible];
TabStop:=假;
使用Header.Columns.Add do
开始
宽度:=
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, VirtualTrees;
type
TVTScrollBarsUpdateEvent = procedure(Sender: TBaseVirtualTree; DoRepaint: Boolean) of object;
TVirtualStringTree = class(VirtualTrees.TVirtualStringTree)
private
FOnUpdateScrollBars: TVTScrollBarsUpdateEvent;
public
procedure UpdateScrollBars(DoRepaint: Boolean); override;
published
property OnUpdateScrollBars: TVTScrollBarsUpdateEvent read FOnUpdateScrollBars write FOnUpdateScrollBars;
end;
type
PNodeSubTree = ^TNodeSubTree;
TNodeSubTree = class
FChildTree: TVirtualStringTree;
end;
type
TForm1 = class(TForm)
Button1: TButton;
VirtualStringTree1: TVirtualStringTree;
procedure FormCreate(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure VirtualStringTree1AfterAutoFitColumns(Sender: TVTHeader);
procedure VirtualStringTree1BeforeDrawTreeLine(Sender: TBaseVirtualTree;
Node: PVirtualNode; Level: Integer; var PosX: Integer);
procedure VirtualStringTree1Collapsed(Sender: TBaseVirtualTree;
Node: PVirtualNode);
procedure VirtualStringTree1ColumnResize(Sender: TVTHeader;
Column: TColumnIndex);
procedure VirtualStringTree1Expanded(Sender: TBaseVirtualTree;
Node: PVirtualNode);
procedure VirtualStringTree1FocusChanging(Sender: TBaseVirtualTree; OldNode,
NewNode: PVirtualNode; OldColumn, NewColumn: TColumnIndex;
var Allowed: Boolean);
procedure VirtualStringTree1FreeNode(Sender: TBaseVirtualTree;
Node: PVirtualNode);
procedure VirtualStringTree1MeasureItem(Sender: TBaseVirtualTree;
TargetCanvas: TCanvas; Node: PVirtualNode; var NodeHeight: Integer);
private
procedure InvalidateSubTrees(Tree: TBaseVirtualTree);
procedure ResizeSubTrees(Tree: TBaseVirtualTree);
procedure UpdateSubTreeBounds(Tree: TBaseVirtualTree; Node: PVirtualNode);
procedure OnUpdateScrollBars(Sender: TBaseVirtualTree; DoRepaint: Boolean);
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
{ TVirtualStringTree }
procedure TVirtualStringTree.UpdateScrollBars(DoRepaint: Boolean);
begin
inherited;
if HandleAllocated and Assigned(FOnUpdateScrollBars) then
FOnUpdateScrollBars(Self, DoRepaint);
end;
{ TForm1 }
procedure TForm1.FormCreate(Sender: TObject);
begin
ReportMemoryLeaksOnShutdown := True;
VirtualStringTree1.NodeDataSize := SizeOf(TNodeSubTree);
VirtualStringTree1.OnUpdateScrollBars := OnUpdateScrollBars;
end;
procedure TForm1.Button1Click(Sender: TObject);
var
Data: PNodeSubTree;
Node: PVirtualNode;
begin
Node := VirtualStringTree1.AddChild(nil);
Node := VirtualStringTree1.AddChild(Node);
VirtualStringTree1.InitNode(Node);
Data := VirtualStringTree1.GetNodeData(Node);
Data^ := TNodeSubTree.Create;
Data^.FChildTree := TVirtualStringTree.Create(nil);
with Data.FChildTree do
begin
Visible := False;
Parent := VirtualStringTree1;
Height := 150;
DefaultNodeHeight := 21;
Header.AutoSizeIndex := 0;
Header.Font.Charset := DEFAULT_CHARSET;
Header.Font.Color := clWindowText;
Header.Font.Height := -11;
Header.Font.Name := 'Tahoma';
Header.Font.Style := [];
Header.Height := 21;
Header.Options := [hoColumnResize, hoDrag, hoShowSortGlyphs, hoVisible];
TabStop := False;
with Header.Columns.Add do
begin
Width := 100;
Text := 'Header item 1';
end;
with Header.Columns.Add do
begin
Width := 100;
Text := 'Header item 2';
end;
end;
end;
procedure TForm1.VirtualStringTree1AfterAutoFitColumns(Sender: TVTHeader);
begin
InvalidateSubTrees(Sender.Treeview);
end;
procedure TForm1.VirtualStringTree1BeforeDrawTreeLine(Sender: TBaseVirtualTree;
Node: PVirtualNode; Level: Integer; var PosX: Integer);
begin
if Level = 1 then
PosX := 0;
end;
procedure TForm1.VirtualStringTree1Collapsed(Sender: TBaseVirtualTree;
Node: PVirtualNode);
var
Data: PNodeSubTree;
begin
Data := VirtualStringTree1.GetNodeData(Node.FirstChild);
if Assigned(Data^) and Assigned(Data^.FChildTree) then
Data^.FChildTree.Visible := False;
end;
procedure TForm1.VirtualStringTree1ColumnResize(Sender: TVTHeader;
Column: TColumnIndex);
begin
ResizeSubTrees(Sender.Treeview);
end;
procedure TForm1.VirtualStringTree1Expanded(Sender: TBaseVirtualTree;
Node: PVirtualNode);
var
Data: PNodeSubTree;
begin
Data := VirtualStringTree1.GetNodeData(Node.FirstChild);
if Assigned(Data^) and Assigned(Data^.FChildTree) then
Data^.FChildTree.Visible := True;
end;
procedure TForm1.VirtualStringTree1FocusChanging(Sender: TBaseVirtualTree;
OldNode, NewNode: PVirtualNode; OldColumn, NewColumn: TColumnIndex;
var Allowed: Boolean);
begin
if Sender.GetNodeLevel(NewNode) = 1 then
begin
Allowed := False;
if Sender.AbsoluteIndex(OldNode) > Sender.AbsoluteIndex(NewNode) then
Sender.FocusedNode := Sender.GetPreviousSibling(OldNode)
else
if OldNode <> Sender.GetLastChild(nil) then
Sender.FocusedNode := Sender.GetNextSibling(OldNode)
else
Sender.FocusedNode := OldNode;
end;
end;
procedure TForm1.VirtualStringTree1FreeNode(Sender: TBaseVirtualTree;
Node: PVirtualNode);
var
Data: PNodeSubTree;
begin
Data := VirtualStringTree1.GetNodeData(Node);
if Assigned(Data^) then
begin
if Assigned(Data^.FChildTree) then
Data^.FChildTree.Free;
Data^.Free;
end;
end;
procedure TForm1.VirtualStringTree1MeasureItem(Sender: TBaseVirtualTree;
TargetCanvas: TCanvas; Node: PVirtualNode; var NodeHeight: Integer);
var
Data: PNodeSubTree;
begin
if VirtualStringTree1.GetNodeLevel(Node) = 1 then
begin
Data := VirtualStringTree1.GetNodeData(Node);
if Assigned(Data^) and Assigned(Data^.FChildTree) then
NodeHeight := Data^.FChildTree.Height + 8;
end;
end;
procedure TForm1.InvalidateSubTrees(Tree: TBaseVirtualTree);
var
Data: PNodeSubTree;
Node: PVirtualNode;
begin
Node := Tree.GetFirst;
while Assigned(Node) do
begin
if Tree.HasChildren[Node] then
begin
Data := Tree.GetNodeData(Node.FirstChild);
if Assigned(Data^) and Assigned(Data^.FChildTree) then
begin
Data^.FChildTree.Header.Invalidate(nil);
Data^.FChildTree.Invalidate;
end;
end;
Node := Tree.GetNextSibling(Node);
end;
end;
procedure TForm1.ResizeSubTrees(Tree: TBaseVirtualTree);
var
Node: PVirtualNode;
begin
Node := Tree.GetFirst;
while Assigned(Node) do
begin
if Tree.HasChildren[Node] then
UpdateSubTreeBounds(Tree, Node.FirstChild);
Node := Tree.GetNextSibling(Node);
end;
end;
procedure TForm1.UpdateSubTreeBounds(Tree: TBaseVirtualTree; Node: PVirtualNode);
var
R: TRect;
Data: PNodeSubTree;
begin
if Assigned(Node) then
begin
Data := Tree.GetNodeData(Node);
if Assigned(Data^) and Assigned(Data^.FChildTree) and
Data^.FChildTree.Visible then
begin
R := Tree.GetDisplayRect(Node, -1, False, True);
R.Left := R.Left + (Tree as TVirtualStringTree).Indent;
R.Top := R.Top + 4;
R.Right := R.Right - 8;
R.Bottom := R.Bottom - 4;
Data^.FChildTree.BoundsRect := R;
end;
end;
end;
procedure TForm1.OnUpdateScrollBars(Sender: TBaseVirtualTree; DoRepaint: Boolean);
begin
ResizeSubTrees(Sender);
end;
end.
object Form1: TForm1
Left = 0
Top = 0
Caption = 'Form1'
ClientHeight = 282
ClientWidth = 468
Color = clBtnFace
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'Tahoma'
Font.Style = []
OldCreateOrder = False
OnCreate = FormCreate
DesignSize = (
468
282)
PixelsPerInch = 96
TextHeight = 13
object VirtualStringTree1: TVirtualStringTree
Left = 8
Top = 8
Width = 371
Height = 266
Anchors = [akLeft, akTop, akRight, akBottom]
Header.AutoSizeIndex = 0
Header.Font.Charset = DEFAULT_CHARSET
Header.Font.Color = clWindowText
Header.Font.Height = -11
Header.Font.Name = 'Tahoma'
Header.Font.Style = []
Header.Height = 21
Header.Options = [hoColumnResize, hoDblClickResize, hoDrag, hoShowSortGlyphs, hoVisible]
TabOrder = 0
TreeOptions.MiscOptions = [toVariableNodeHeight]
OnAfterAutoFitColumns = VirtualStringTree1AfterAutoFitColumns
OnBeforeDrawTreeLine = VirtualStringTree1BeforeDrawTreeLine
OnCollapsed = VirtualStringTree1Collapsed
OnColumnResize = VirtualStringTree1ColumnResize
OnExpanded = VirtualStringTree1Expanded
OnFocusChanging = VirtualStringTree1FocusChanging
OnFreeNode = VirtualStringTree1FreeNode
OnMeasureItem = VirtualStringTree1MeasureItem
ExplicitWidth = 581
ExplicitHeight = 326
Columns = <
item
Position = 0
Width = 75
WideText = 'Column 1'
end
item
Position = 1
Width = 75
WideText = 'Column 2'
end
item
Position = 2
Width = 75
WideText = 'Column 3'
end>
end
object Button1: TButton
Left = 385
Top = 8
Width = 75
Height = 25
Anchors = [akTop, akRight]
Caption = 'Button1'
TabOrder = 1
OnClick = Button1Click
ExplicitLeft = 595
end
end