使用 IntraWeb (19)

这是个饱受非议的控件; 我通过尝试, 理解了非议, 也能理解作者. 总之向作者的思路靠拢吧, 还是不错的.

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TIWTreeView 所在单元及继承链:
IWCompTreeview.TIWTreeView < TIWCustomControl < TIWBaseHTMLControl < TIWBaseControl < TIWVCLBaseControl < TControl < TComponent < TPersistent < TObject

主要成员:

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property Items: TIWTreeViewItems    //所有 Item 的集合
property Selected: TIWTreeViewItem  //在这里, 叫做 "当前 Item" 更合适
property AutoIndent: Boolean               //是否自动缩排; 默认 True
property DoServerSidePlusMinus: Boolean    //如果是 True, Html 中不包含被折叠的部分, 需要展开时再从服务器读取; 相反, Html 中包含所有节点; 默认 False
property TreeViewImages: TIWTreeViewImages //通过其 OpenFolderImage、ClosedFolderImage、DocumentImage、PlusImage、MinusImage 子属性指定五个图标
property ItemSpace: TIWTreeViewItemSpace //调整纵、横间距
property UseItemImages: Boolean          //是否使用 Item 标志图像
property TreeViewImagesWidth: Integer    //图标宽度
property TreeViewImagesHeigth: Integer   //图标高度
property UseFrame: Boolean               //是否使用框架
property ScrollToName: string            //滚动到指定名称的 Item
property ScrollBars: TIWScrollStyle      //滚动条选项
property WrapItems: Boolean              //Item 文本能否换行; 默认 False
property DoRefreshControl: Boolean       //在修改某些属性时必须让它为 True 才会有效

property TreeItemClick: TIWTreeViewClickEvent //通过它可以为每个 Item 指定 Click 事件
property OnPlusMinus: TTreeViewPlusMinusProc  //每当展开或收拢子节点时

procedure ClearAll  //

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TIWTreeViewItems 与 TIWTreeViewItem:

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{IWCompTreeview.TIWTreeViewItems < TOwnedCollection < TCollection < TPersistent < TObject}
property Count: Integer
property Items[AIndex: Integer]: TIWTreeViewItem

function Add(aParentItem: TIWTreeViewItem): TIWTreeViewItem
procedure Clear
procedure Delete(Index: Integer)
function Insert(Index: Integer): TCollectionItem

{IWCompTreeview.TIWTreeViewItem < TCollectionItem < TPersistent < TObject}
property ParentItem: TIWTreeViewItem
property SubItems: TList
property UserData: TObject
property Caption: string
property Expanded: Boolean
property Font: TIWFont
property Hint: string
property ItemImages: TIWTreeViewImages
property Tag: Integer
property URL: string
property Version: Integer
property Css: string
property Collection: TCollection
property ID: Integer
property Index: Integer
property Name: string
property DisplayName: string

property OnClick: TNotifyEvent

procedure DoClick
function HasChild: Boolean

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测试:

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{在空白窗体上放 IWRegion1 和 IWTreeView1; 下面代码在设计时实现会更方便}
procedure TIWForm1.IWAppFormCreate(Sender: TObject);
var
  fItem: TIWTreeViewItem;
begin
  IWRegion1.Width := 200;
  IWRegion1.Align := alLeft;
  IWRegion1.Color := clWebYellow;
  LinkColor := clWebRed; //如果给 TIWTreeViewItem 指定了 OnClick 事件, 它会被呈现为链接

  IWTreeView1.Parent := IWRegion1;
  IWTreeView1.Align := alClient;

  IWTreeView1.Items.Add(nil).Caption := 'ItemA';
  IWTreeView1.Items.Add(nil).Caption := 'ItemB';
  IWTreeView1.Items.Add(nil).Caption := 'ItemC';

  fItem := IWTreeView1.Items.Add(nil);
  fItem.Caption := 'ItemD';
    IWTreeView1.Items.Add(fItem).Caption := 'ItemD1';
    IWTreeView1.Items.Add(fItem).Caption := 'ItemD2';

    fItem := IWTreeView1.Items.Add(fItem);
    fItem.Caption := 'ItemD3';
      IWTreeView1.Items.Add(fItem).Caption := 'ItemD31';
      IWTreeView1.Items.Add(fItem).Caption := 'ItemD32';
end;

{尽管可以为每个 Item 指定 OnClick, 但我觉得用 TreeItemClick 事件一起指定更方便; 事件中可以通过其 Tag、ID、Name、Caption等来区别}
procedure TIWForm1.IWTreeView1TreeItemClick(Sender: TObject; ATreeViewItem: TIWTreeViewItem);
begin
  if not ATreeViewItem.HasChild then
    WebApplication.ShowMessage(ATreeViewItem.Caption);
end;

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效果图:

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