Spring4D [inject] 属性在内部如何发挥作用?
How does the Spring4D [inject] attribute function internally?
我正在尝试创建一个最小示例,它与 Spring4D [inject]
属性的作用相同。它应该自动解析我的 TOrderAdapter.FDetailsAdapter
,我想在 Factory 单元内手动实例化它(不像 Spring4D 容器那样工作,首先从外部注册接口)。 Factory 应该分发使用 [inject]
请求的任何所需接口。
很明显,我的代码无法工作(TOrderAdapter.FDetailsAdapter
没有被注入,在 ButtonClick
上给我一个 nil
指针访问冲突,第一次使用)。通读 Spring4D 源代码,我看不出这个 逻辑部分 在哪里,我缺少 以在我的示例中使用所需的功能.
program OrderDetails;
uses
Vcl.Forms,
Order.Adapter in 'Order.Adapter.pas',
Details in 'Details.pas',
Details.Adapter in 'Details.Adapter.pas',
Factory.Adapter in 'Factory.Adapter.pas',
Factory in 'Factory.pas',
Order in 'Order.pas',
Order.View in 'Order.View.pas' {OrderForm};
{$R *.res}
begin
Application.Initialize;
Application.MainFormOnTaskbar := True;
Application.CreateForm(TOrderForm, OrderForm);
Factory.Adapter.Factory := TFactoryAdapter.Create;
Application.Run;
end.
unit Factory;
uses
Rtti, TypInfo;
type
InjectAttribute = class(TCustomAttribute)
private
fServiceType: PTypeInfo;
fValue: TValue;
public
constructor Create(ServiceType: PTypeInfo); overload;
property ServiceType: PTypeInfo read fServiceType;
property Value: TValue read fValue;
end;
implementation
constructor InjectAttribute.Create(ServiceType: PTypeInfo);
begin
inherited Create;
fServiceType := ServiceType;
end;
end.
unit Factory.Adapter;
uses
Details, Details.Adapter, Order, Order.Adapter;
type
TFactoryAdapter = class
private
FDetailsAdapter: IDetailsAdapter;
FOrderAdapter: IOrderAdapter;
public
constructor Create;
function Inject: IInterface; overload; // unused
end;
var
Factory: TFactoryAdapter;
implementation
constructor TFactoryAdapter.Create;
begin
FDetailsAdapter := TDetailsAdapter.Create;
FOrderAdapter := TOrderAdapter.Create;
end;
function TFactoryAdapter.Inject: IInterface; // unused
begin
Result := FDetailsAdapter;
end;
end.
unit Details.Adapter;
uses
Details, Winapi.Windows, SysUtils;
type
TDetailsAdapter = class(TInterfacedObject, IDetailsAdapter)
private
FID: Integer;
public
procedure SetID(AID: Integer);
function GetID: Integer;
published
property ID: Integer read GetID write SetID;
end;
implementation
procedure TDetailsAdapter.SetID(AID: Integer);
begin
FID := AID;
OutputDebugString(PWideChar('OrderDetail ID set to ' + IntToStr(FID)));
end;
function TDetailsAdapter.GetID: Integer;
begin
Result := FID;
end;
end.
unit Order.Adapter;
uses
Order, Order.View, Details, Factory,
Vcl.Forms;
type
TOrderAdapter = class(TInterfacedObject, IOrderAdapter)
private
[inject]
FDetailsAdapter: IDetailsAdapter;
public
constructor Create;
procedure ButtonClick(Sender: TObject);
end;
var
OrderForm: TOrderForm;
implementation
constructor TOrderAdapter.Create;
begin
OrderForm.Button1.OnClick := ButtonClick;
end;
procedure TOrderAdapter.ButtonClick(Sender: TObject);
begin
FDetailsAdapter.ID := 5;
end;
end.
容器使用 RTTI 收集具有此属性的成员,并将正确的服务注入其中。
我正在尝试创建一个最小示例,它与 Spring4D [inject]
属性的作用相同。它应该自动解析我的 TOrderAdapter.FDetailsAdapter
,我想在 Factory 单元内手动实例化它(不像 Spring4D 容器那样工作,首先从外部注册接口)。 Factory 应该分发使用 [inject]
请求的任何所需接口。
很明显,我的代码无法工作(TOrderAdapter.FDetailsAdapter
没有被注入,在 ButtonClick
上给我一个 nil
指针访问冲突,第一次使用)。通读 Spring4D 源代码,我看不出这个 逻辑部分 在哪里,我缺少 以在我的示例中使用所需的功能.
program OrderDetails;
uses
Vcl.Forms,
Order.Adapter in 'Order.Adapter.pas',
Details in 'Details.pas',
Details.Adapter in 'Details.Adapter.pas',
Factory.Adapter in 'Factory.Adapter.pas',
Factory in 'Factory.pas',
Order in 'Order.pas',
Order.View in 'Order.View.pas' {OrderForm};
{$R *.res}
begin
Application.Initialize;
Application.MainFormOnTaskbar := True;
Application.CreateForm(TOrderForm, OrderForm);
Factory.Adapter.Factory := TFactoryAdapter.Create;
Application.Run;
end.
unit Factory;
uses
Rtti, TypInfo;
type
InjectAttribute = class(TCustomAttribute)
private
fServiceType: PTypeInfo;
fValue: TValue;
public
constructor Create(ServiceType: PTypeInfo); overload;
property ServiceType: PTypeInfo read fServiceType;
property Value: TValue read fValue;
end;
implementation
constructor InjectAttribute.Create(ServiceType: PTypeInfo);
begin
inherited Create;
fServiceType := ServiceType;
end;
end.
unit Factory.Adapter;
uses
Details, Details.Adapter, Order, Order.Adapter;
type
TFactoryAdapter = class
private
FDetailsAdapter: IDetailsAdapter;
FOrderAdapter: IOrderAdapter;
public
constructor Create;
function Inject: IInterface; overload; // unused
end;
var
Factory: TFactoryAdapter;
implementation
constructor TFactoryAdapter.Create;
begin
FDetailsAdapter := TDetailsAdapter.Create;
FOrderAdapter := TOrderAdapter.Create;
end;
function TFactoryAdapter.Inject: IInterface; // unused
begin
Result := FDetailsAdapter;
end;
end.
unit Details.Adapter;
uses
Details, Winapi.Windows, SysUtils;
type
TDetailsAdapter = class(TInterfacedObject, IDetailsAdapter)
private
FID: Integer;
public
procedure SetID(AID: Integer);
function GetID: Integer;
published
property ID: Integer read GetID write SetID;
end;
implementation
procedure TDetailsAdapter.SetID(AID: Integer);
begin
FID := AID;
OutputDebugString(PWideChar('OrderDetail ID set to ' + IntToStr(FID)));
end;
function TDetailsAdapter.GetID: Integer;
begin
Result := FID;
end;
end.
unit Order.Adapter;
uses
Order, Order.View, Details, Factory,
Vcl.Forms;
type
TOrderAdapter = class(TInterfacedObject, IOrderAdapter)
private
[inject]
FDetailsAdapter: IDetailsAdapter;
public
constructor Create;
procedure ButtonClick(Sender: TObject);
end;
var
OrderForm: TOrderForm;
implementation
constructor TOrderAdapter.Create;
begin
OrderForm.Button1.OnClick := ButtonClick;
end;
procedure TOrderAdapter.ButtonClick(Sender: TObject);
begin
FDetailsAdapter.ID := 5;
end;
end.
容器使用 RTTI 收集具有此属性的成员,并将正确的服务注入其中。