我需要了解制作组件生成和管理子组件背后的基础知识。我最初是通过创建TCollection
来尝试此操作,并尝试在每个TCollectionItem
上添加一个名称。但我知道这并不像我希望的那么容易。
所以现在我将再次从头开始这个项目,这次我想说得对。这些子组件不是可视组件,不应具有任何显示或窗口,仅基于TComponent
。保存这些子组件的主要组件也将基于TComponent
。所以这里没有什么是视觉的,我不希望在我的表格上(在设计时间内)为每个子组件设置一个小图标。
我希望能够以类似集合的方式维护和管理这些子组件。重要的是应该创建,命名这些子组件并将其添加到表单源,就像菜单项一样。这是这个想法的重点,如果它们不能被命名,那么整个想法就是kaput。
哦,另一件重要的事情是:作为所有子组件的父组件的主要组件需要能够将这些子组件保存到DFM文件中。
示例:
而不是访问其中一个子项,如:
MyForm.MyItems[1].DoSomething();
我宁愿做类似的事情:
MyForm.MyItem2.DoSomething();
所以我不必依赖于知道每个子项的ID。
修改
我认为有必要包含我的原始代码,以便可以看到原始集合的工作原理。这里只是整个单元中剥离的服务器端集合和收集项目:
// Command Collections
// Goal: Allow entering pre-set commands with unique Name and ID
// Each command has its own event which is triggered when command is received
// TODO: Name each collection item as a named component in owner form
//Determines how commands are displayed in collection editor in design-time
TJDCmdDisplay = (cdName, cdID, cdCaption, cdIDName, cdIDCaption);
TJDScktSvrCmdEvent = procedure(Sender: TObject; Socket: TJDServerClientSocket;
const Data: TStrings) of object;
TSvrCommands = class(TCollection)
private
fOwner: TPersistent;
fOnUnknownCommand: TJDScktSvrCmdEvent;
fDisplay: TJDCmdDisplay;
function GetItem(Index: Integer): TSvrCommand;
procedure SetItem(Index: Integer; Value: TSvrCommand);
procedure SetDisplay(const Value: TJDCmdDisplay);
protected
function GetOwner: TPersistent; override;
public
constructor Create(AOwner: TPersistent);
destructor Destroy;
procedure DoCommand(const Socket: TJDServerClientSocket;
const Cmd: Integer; const Data: TStrings);
function Add: TSvrCommand;
property Items[Index: Integer]: TSvrCommand read GetItem write SetItem;
published
property Display: TJDCmdDisplay read fDisplay write SetDisplay;
property OnUnknownCommand: TJDScktSvrCmdEvent
read fOnUnknownCommand write fOnUnknownCommand;
end;
TSvrCommand = class(TCollectionItem)
private
fID: Integer;
fOnCommand: TJDScktSvrCmdEvent;
fName: String;
fParamCount: Integer;
fCollection: TSvrCommands;
fCaption: String;
procedure SetID(Value: Integer);
procedure SetName(Value: String);
procedure SetCaption(const Value: String);
protected
function GetDisplayName: String; override;
public
procedure Assign(Source: TPersistent); override;
constructor Create(Collection: TCollection); override;
destructor Destroy; override;
published
property ID: Integer read fID write SetID;
property Name: String read fName write SetName;
property Caption: String read fCaption write SetCaption;
property ParamCount: Integer read fParamCount write fParamCount;
property OnCommand: TJDScktSvrCmdEvent read fOnCommand write fOnCommand;
end;
////////////////////////////////////////////////////////////////////////////////
implementation
////////////////////////////////////////////////////////////////////////////////
{ TSvrCommands }
function TSvrCommands.Add: TSvrCommand;
begin
Result:= inherited Add as TSvrCommand;
end;
constructor TSvrCommands.Create(AOwner: TPersistent);
begin
inherited Create(TSvrCommand);
Self.fOwner:= AOwner;
end;
destructor TSvrCommands.Destroy;
begin
inherited Destroy;
end;
procedure TSvrCommands.DoCommand(const Socket: TJDServerClientSocket;
const Cmd: Integer; const Data: TStrings);
var
X: Integer;
C: TSvrCommand;
F: Bool;
begin
F:= False;
for X:= 0 to Self.Count - 1 do begin
C:= GetItem(X);
if C.ID = Cmd then begin
F:= True;
try
if assigned(C.fOnCommand) then
C.fOnCommand(Self, Socket, Data);
except
on e: exception do begin
raise Exception.Create(
'Failed to execute command '+IntToStr(Cmd)+': '+#10+e.Message);
end;
end;
Break;
end;
end;
if not F then begin
//Command not found
end;
end;
function TSvrCommands.GetItem(Index: Integer): TSvrCommand;
begin
Result:= TSvrCommand(inherited GetItem(Index));
end;
function TSvrCommands.GetOwner: TPersistent;
begin
Result:= fOwner;
end;
procedure TSvrCommands.SetDisplay(const Value: TJDCmdDisplay);
begin
fDisplay := Value;
end;
procedure TSvrCommands.SetItem(Index: Integer; Value: TSvrCommand);
begin
inherited SetItem(Index, Value);
end;
{ TSvrCommand }
procedure TSvrCommand.Assign(Source: TPersistent);
begin
inherited;
end;
constructor TSvrCommand.Create(Collection: TCollection);
begin
inherited Create(Collection);
fCollection:= TSvrCommands(Collection);
end;
destructor TSvrCommand.Destroy;
begin
inherited Destroy;
end;
function TSvrCommand.GetDisplayName: String;
begin
case Self.fCollection.fDisplay of
cdName: begin
Result:= fName;
end;
cdID: begin
Result:= '['+IntToStr(fID)+']';
end;
cdCaption: begin
Result:= fCaption;
end;
cdIDName: begin
Result:= '['+IntToStr(fID)+'] '+fName;
end;
cdIDCaption: begin
Result:= '['+IntToStr(fID)+'] '+fCaption;
end;
end;
end;
procedure TSvrCommand.SetCaption(const Value: String);
begin
fCaption := Value;
end;
procedure TSvrCommand.SetID(Value: Integer);
begin
fID:= Value;
end;
procedure TSvrCommand.SetName(Value: String);
begin
fName:= Value;
end;
答案 0 :(得分:8)
This Thread帮助我创造了一些东西。我拿了包贴在那里并修改了一下。这是来源:
<强> TestComponents.pas 强>
unit TestComponents;
interface
uses
Classes;
type
TParentComponent = class;
TChildComponent = class(TComponent)
private
FParent: TParentComponent;
procedure SetParent(const Value: TParentComponent);
protected
procedure SetParentComponent(AParent: TComponent); override;
public
destructor Destroy; override;
function GetParentComponent: TComponent; override;
function HasParent: Boolean; override;
property Parent: TParentComponent read FParent write SetParent;
end;
TParentComponent = class(TComponent)
private
FChilds: TList;
protected
procedure GetChildren(Proc: TGetChildProc; Root: TComponent); override;
public
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
property Childs: TList read FChilds;
end;
implementation
{ TChildComponent }
destructor TChildComponent.Destroy;
begin
Parent := nil;
inherited;
end;
function TChildComponent.GetParentComponent: TComponent;
begin
Result := FParent;
end;
function TChildComponent.HasParent: Boolean;
begin
Result := Assigned(FParent);
end;
procedure TChildComponent.SetParent(const Value: TParentComponent);
begin
if FParent <> Value then
begin
if Assigned(FParent) then
FParent.FChilds.Remove(Self);
FParent := Value;
if Assigned(FParent) then
FParent.FChilds.Add(Self);
end;
end;
procedure TChildComponent.SetParentComponent(AParent: TComponent);
begin
if AParent is TParentComponent then
SetParent(AParent as TParentComponent);
end;
{ TParentComponent }
constructor TParentComponent.Create(AOwner: TComponent);
begin
inherited;
FChilds := TList.Create;
end;
destructor TParentComponent.Destroy;
var
I: Integer;
begin
for I := 0 to FChilds.Count - 1 do
FChilds[0].Free;
FChilds.Free;
inherited;
end;
procedure TParentComponent.GetChildren(Proc: TGetChildProc; Root: TComponent);
var
i: Integer;
begin
for i := 0 to FChilds.Count - 1 do
Proc(TComponent(FChilds[i]));
end;
end.
<强> TestComponentsReg.pas 强>
unit TestComponentsReg;
interface
uses
Classes,
DesignEditors,
DesignIntf,
TestComponents;
type
TParentComponentEditor = class(TComponentEditor)
procedure ExecuteVerb(Index: Integer); override;
function GetVerb(Index: Integer): string; override;
function GetVerbCount: Integer; override;
end;
procedure Register;
implementation
uses
ColnEdit;
type
TChildComponentCollectionItem = class(TCollectionItem)
private
FChildComponent: TChildComponent;
function GetName: string;
procedure SetName(const Value: string);
protected
property ChildComponent: TChildComponent read FChildComponent write FChildComponent;
function GetDisplayName: string; override;
public
constructor Create(Collection: TCollection); override;
destructor Destroy; override;
published
property Name: string read GetName write SetName;
end;
TChildComponentCollection = class(TOwnedCollection)
private
FDesigner: IDesigner;
public
property Designer: IDesigner read FDesigner write FDesigner;
end;
procedure Register;
begin
RegisterClass(TChildComponent);
RegisterNoIcon([TChildComponent]);
RegisterComponents('Test', [TParentComponent]);
RegisterComponentEditor(TParentComponent, TParentComponentEditor);
end;
{ TParentComponentEditor }
procedure TParentComponentEditor.ExecuteVerb(Index: Integer);
var
LCollection: TChildComponentCollection;
i: Integer;
begin
LCollection := TChildComponentCollection.Create(Component, TChildComponentCollectionItem);
LCollection.Designer := Designer;
for i := 0 to TParentComponent(Component).Childs.Count - 1 do
with TChildComponentCollectionItem.Create(nil) do
begin
ChildComponent := TChildComponent(TParentComponent(Component).Childs[i]);
Collection := LCollection;
end;
ShowCollectionEditorClass(Designer, TCollectionEditor, Component, LCollection, 'Childs');
end;
function TParentComponentEditor.GetVerb(Index: Integer): string;
begin
Result := 'Edit Childs...';
end;
function TParentComponentEditor.GetVerbCount: Integer;
begin
Result := 1;
end;
{ TChildComponentCollectionItem }
constructor TChildComponentCollectionItem.Create(Collection: TCollection);
begin
inherited;
if Assigned(Collection) then
begin
FChildComponent := TChildComponent.Create(TComponent(TOwnedCollection(Collection).Owner).Owner);
FChildComponent.Name := TChildComponentCollection(Collection).Designer.UniqueName(TChildComponent.ClassName);
FChildComponent.Parent := TParentComponent(TComponent(TOwnedCollection(Collection).Owner));
end;
end;
destructor TChildComponentCollectionItem.Destroy;
begin
FChildComponent.Free;
inherited;
end;
function TChildComponentCollectionItem.GetDisplayName: string;
begin
Result := FChildComponent.Name;
end;
function TChildComponentCollectionItem.GetName: string;
begin
Result := FChildComponent.Name;
end;
procedure TChildComponentCollectionItem.SetName(const Value: string);
begin
FChildComponent.Name := Value;
end;
end.
最重要的是RegisterNoIcon,它可以防止在创建表单时在组件上显示该组件。 TChildComponent中重写的方法导致它们嵌套在TParentComponent中。
编辑:我添加了一个临时集合来编辑内置TCollectionEditor中的项目,而不必编写自己的项目。唯一的缺点是TChildComponentCollectionItem必须发布TChildComponent已发布的每个属性,以便能够在OI中编辑它们。
答案 1 :(得分:2)
使用TComponent.SetSubComponent
例程:
type
TComponent1 = class(TComponent)
private
FSubComponent: TComponent;
procedure SetSubComponent(Value: TComponent);
public
constructor Create(AOwner: TComponent); override;
published
property SubComponent: TComponent read FSubComponent write SetSubComponent;
end;
procedure Register;
implementation
procedure Register;
begin
RegisterComponents('Samples', [TComponent1]);
end;
{ TComponent1 }
constructor TComponent1.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
FSubComponent := TComponent.Create(Self); // Nót AOwner as owner here !!
FSubComponent.Name := 'MyName';
FSubComponent.SetSubComponent(True);
end;
procedure TComponent1.SetSubComponent(Value: TComponent);
begin
FSubComponent.Assign(Value);
end;
我现在明白这个子组件将是集合项的一部分。在这种情况下:没有区别,请使用此方法。
答案 2 :(得分:1)
实施TCollectionItem.GetDisplayName
以“命名”收集项目。
关于集合:当这是一个已发布的属性时,该集合将自动命名为属性名称。
创建TPersistent
的属性时要小心implement GetOwner
。