4

我有一个弹出菜单，里面有一些项目。 

选项1
 - 子 1
 - 子 2
选项 2
 - 子 1
 - 子 2
选项 3
 - 子 1
 - 子 2

我希望能够向选项 3 sub2 添加一个子子菜单，所以它看起来像：

选项1
 - 子 1
 - 子 2
选项 2
 - 子 1
 - 子 2
选项 3
 - 子 1
 - 子 2
   - 动态项目1
   - 动态项目2
   - 动态物品3

我一直在尝试使用下面的代码来解决这个问题，我可以做到“如果”菜单选项不存在（选项 3），但如果选项 3 已经存在（它会创建一个重复菜单选项）

我该怎么做？

谢谢


unit Unit2;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, Menus, StdCtrls;

type
  TForm2 = class(TForm)
    popMenu: TPopupMenu;
    gbDynamic: TGroupBox;
    gbMain: TGroupBox;
    popDynamic: TPopupMenu;
    Option11: TMenuItem;
    Option21: TMenuItem;
    Option31: TMenuItem;
    Sub11: TMenuItem;
    Sub21: TMenuItem;
    Item11: TMenuItem;
    Item21: TMenuItem;
    Item31: TMenuItem;
    Item41: TMenuItem;
    Sub12: TMenuItem;
    Sub22: TMenuItem;
    Sub13: TMenuItem;
    Sub23: TMenuItem;
    Option12: TMenuItem;
    Sub24: TMenuItem;
    Sub14: TMenuItem;
    Option22: TMenuItem;
    Sub25: TMenuItem;
    Sub15: TMenuItem;
    Option32: TMenuItem;
    Sub26: TMenuItem;
    Sub16: TMenuItem;
    Label1: TLabel;
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    Procedure PopupItemClick ( Sender : TObject );
  end;

var
  Form2: TForm2;
  stlist: TStrings;

implementation

{$R *.dfm}

procedure TForm2.FormCreate(Sender: TObject);
Var
     menuItem,SubItem : TMenuItem;
     I, N : Integer;
     s : String;

begin
//This will be a downloaded list from a server.
   stlist := TStringList.Create;
     stlist.Add ( 'Item 1' );
     stlist.Add ( 'Item 2' );
     stlist.Add ( 'Item 3' );

     SubItem := TMenuItem.Create(popDynamic);
     SubItem.Caption := 'Option 3';
     popDynamic.Items.Add(SubItem);

     MenuItem := TMenuItem.Create(popDynamic);
     MenuItem.Caption := 'Sub 1';
     SubItem.Add(MenuItem);
     //This would work if Option 3 menu item was not aleady a menu item.

       For I := 0 To stlist.Count - 1 Do
          Begin
          SubItem := TMenuItem.Create ( popDynamic );
          SubItem.Caption := stlist [i];
          SubItem.OnClick := PopupItemClick;
          //assign it a custom integer value..
          SubItem.Tag := i;
          MenuItem.Add(SubItem);
          End;
end;
Procedure TForm2.PopupItemClick ( Sender : TObject );
Var
     menuItem : TMenuItem;
Begin
     menuItem := TMenuItem ( sender );
     label1.caption := stlist.Strings [menuItem.Tag];
End;
end.

形式： 

object Form2: TForm2
  Left = 0
  Top = 0
  Caption = 'Form2'
  ClientHeight = 247
  ClientWidth = 480
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  OnCreate = FormCreate
  PixelsPerInch = 96
  TextHeight = 13
  object gbDynamic: TGroupBox
    Left = 0
    Top = 0
    Width = 217
    Height = 247
    Align = alLeft
    Caption = 'Dynamic'
    PopupMenu = popDynamic
    TabOrder = 0
    object Label1: TLabel
      Left = 48
      Top = 32
      Width = 31
      Height = 13
      Caption = 'Label1'
    end
  end
  object gbMain: TGroupBox
    Left = 217
    Top = 0
    Width = 263
    Height = 247
    Align = alClient
    Caption = 'What I Want Dynamically Created'
    PopupMenu = popMenu
    TabOrder = 1
    ExplicitLeft = 336
    ExplicitTop = 72
    ExplicitWidth = 185
    ExplicitHeight = 105
  end
  object popDynamic: TPopupMenu
    Left = 136
    Top = 96
    object Option12: TMenuItem
      Caption = 'Option 1'
      object Sub14: TMenuItem
        Caption = 'Sub 1'
      end
      object Sub24: TMenuItem
        Caption = 'Sub 2'
      end
    end
    object Option22: TMenuItem
      Caption = 'Option 2'
      object Sub15: TMenuItem
        Caption = 'Sub 1'
      end
      object Sub25: TMenuItem
        Caption = 'Sub 2'
      end
    end
    object Option32: TMenuItem
      Caption = 'Option 3'
      object Sub16: TMenuItem
        Caption = 'Sub 1'
      end
      object Sub26: TMenuItem
        Caption = 'Sub 2'
      end
    end
  end
  object popMenu: TPopupMenu
    Left = 256
    Top = 112
    object Option11: TMenuItem
      Caption = 'Option 1'
      object Sub13: TMenuItem
        Caption = 'Sub 1'
      end
      object Sub23: TMenuItem
        Caption = 'Sub 2'
      end
    end
    object Option21: TMenuItem
      Caption = 'Option 2'
      object Sub12: TMenuItem
        Caption = 'Sub 1'
      end
      object Sub22: TMenuItem
        Caption = 'Sub 2'
      end
    end
    object Option31: TMenuItem
      Caption = 'Option 3'
      object Sub11: TMenuItem
        Caption = 'Sub 1'
        object Item11: TMenuItem
          Caption = 'Item 1'
        end
        object Item21: TMenuItem
          Caption = 'Item 2'
        end
        object Item31: TMenuItem
          Caption = 'Item 3'
        end
        object Item41: TMenuItem
          Caption = 'Item 4'
        end
      end
      object Sub21: TMenuItem
        Caption = 'Sub 2'
      end
    end
  end
end

4

2 回答 2

3

最简单的方法是给 Option3 一个名字，然后在循环中检查它：

 SubItem := nil;
 for i := 0 to popdynamic.Items.Count-1 do
   if SameText(popdynamic.Items[i].Name, 'mnuOption3') then
     SubItem := popdynamic.Items[i];

 if SubItem = nil then
   begin
     SubItem := TMenuItem.Create(popDynamic);
     SubItem.Caption := 'Option 3';
     Subitem.Name := 'mnuOption3';
     popDynamic.Items.Add(SubItem);
   end;

这样，如果它已经存在，您就不会创建新的子项。

于 2010-02-26T23:02:31.153 回答
1

创建新子菜单所需要做的就是引用现有菜单项 - 如果每次都相同，则直接引用该对象，否则，以某种方式找到它 - 然后使用您想要的 TMenuItem 在其上调用 Add加上。我在我的一个应用程序中使用类似的东西从 XML 文件递归地构建菜单。

这应该作为我正在做的事情的一个非常浓缩的版本。

procedure TMainForm.AddMenuItems(XMLNode: IXMLDOMNode; Parent: TMenuItem);
var
  node: IXMLNode;
  item: TMenuItem;
begin
  for i := 0 to XMLNode.childNodes.length - 1 do begin
    node := XMLNode.childNodes.item[i];
    item := NewItem(node.attributes.getNamedItem('name').nodeValue, 0, false, true, nil, 0, '');
    if node.nodeName = 'group' then begin
      Parent.Add(item);
      AddMenuItems(node, item);
    end else begin
      //You probably want to add a Tag to your items so you can tell them apart.
      item.OnClick := DynamicItemClick;
      Parent.Add(item);
    end;
  end;
end;

procedure TMainForm.LoadData;
var
  XMLNode: IXMLNode;
  //...
begin
  //Clear old dynamic items
  while Set1.Count > 0 do
    Set1.Items[0].Free;
  //Open XML file, find right XMLNode...
  AddMenuItems(XMLNode.firstChild, Set1, '');
end;

...其中 Set1 是我正在为其构建菜单项的菜单项。在你的情况下，我猜那将是 Sub26 （和 Sub23 用于弹出菜单中的那个）。只需使用这种基本方法，用读取文件所需的任何内容替换 XML 内容。

于 2010-02-27T02:00:54.620 回答