Delphi 通用框架
Delphi generic frame
我还在这里带着关于 Delphi 帧的问题。
我想创建一个应用程序,它使用各种类型的框架来管理不同的数据库表,所以为了了解如何完成此类任务,我创建了一个简单的 Delphi 表单:
unit main;
interface
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,
System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs,
Vcl.StdCtrls, Vcl.ExtCtrls, FramesManagement;
type
TfrmMain = class(TForm)
pnlCommands: TPanel;
pnlFrames: TPanel;
btnFrame1: TButton;
btnFrame2: TButton;
procedure FormCreate(Sender: TObject);
procedure btnFrame1Click(Sender: TObject);
procedure btnFrame2Click(Sender: TObject);
private
FFrame: IFrameManagement;
public
{ Public declarations }
end;
var
frmMain: TfrmMain;
implementation
{$R *.dfm}
uses Frame1, Frame2;
procedure TfrmMain.FormCreate(Sender: TObject);
begin
FFrame := TFramemanagement.Create;
end;
procedure TfrmMain.btnFrame1Click(Sender: TObject);
begin
FFrame.CreateGenericFrame(pnlFrames, TFrame(Frame1.TFra1));
end;
procedure TfrmMain.btnFrame2Click(Sender: TObject);
begin
FFrame.CreateGenericFrame(pnlFrames, TFrame(Frame2.TFra2));
end;
end.
此表单使用如下声明的接口:
unit FramesManagement;
interface
uses
Vcl.Forms, Vcl.StdCtrls, Vcl.ExtCtrls, Frame1, Frame2;
type
IFrameManagement = interface
['{A00E0D1B-3438-4DC4-9794-702E8302B567}']
procedure CreateGenericFrame(ParentPanel: TPanel; FrameName: TFrame);
end;
TFrameManagement = class(TInterfacedObject, IFrameManagement)
private
genericFrame: TFrame;
procedure CreateGenericFrame(ParentPanel: TPanel; FrameName: TFrame);
end;
implementation
procedure TFrameManagement.CreateGenericFrame(ParentPanel: TPanel;
FrameName: TFrame);
begin
genericFrame := FrameName.Create(ParentPanel);
genericFrame.Parent := ParentPanel;
end;
这里有两个框架。
第 1 帧:
unit Frame1;
interface
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,
System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs,
Vcl.StdCtrls;
type
TFra1 = class(TFrame)
txtFrame1: TStaticText;
txtFrameType: TStaticText;
lblFrameType: TLabel;
private
public
end;
implementation
{$R *.dfm}
end.
和第 2 帧:
unit Frame2;
interface
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,
System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs,
Vcl.StdCtrls;
type
TFra2 = class(TFrame)
txtFrame2: TStaticText;
txtFrameType: TStaticText;
lblFrameType: TLabel;
private
public
end;
implementation
{$R *.dfm}
end.
这是所有代码,但是当我 运行 应用程序并尝试创建第一帧或第二帧时,我收到如下错误:
我认为解决方案可能是使用泛型,但我不知道如何使用它们。我的想法是对的还是有另一种方法可以达到这个目标?
谁能帮帮我?
procedure TFrameManagement.CreateGenericFrame(ParentPanel: TPanel; FrameName: TFrame);
begin
genericFrame := FrameName.Create(ParentPanel);
genericFrame.Parent := ParentPanel;
end;
这里 FrameName
是一个实例,您正在调用该实例的构造函数。您没有按照您的意愿创建新实例。
您需要使用元 类。
type
TFrameClass = class of TFrame;
procedure TFrameManagement.CreateGenericFrame(ParentPanel: TPanel; FrameClass: TFrameClass);
begin
genericFrame := FrameClass.Create(ParentPanel);
genericFrame.Parent := ParentPanel;
end;
你可以这样称呼:
FFrame.CreateGenericFrame(pnlFrames, Frame2.TFra2);
我还在这里带着关于 Delphi 帧的问题。 我想创建一个应用程序,它使用各种类型的框架来管理不同的数据库表,所以为了了解如何完成此类任务,我创建了一个简单的 Delphi 表单:
unit main;
interface
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,
System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs,
Vcl.StdCtrls, Vcl.ExtCtrls, FramesManagement;
type
TfrmMain = class(TForm)
pnlCommands: TPanel;
pnlFrames: TPanel;
btnFrame1: TButton;
btnFrame2: TButton;
procedure FormCreate(Sender: TObject);
procedure btnFrame1Click(Sender: TObject);
procedure btnFrame2Click(Sender: TObject);
private
FFrame: IFrameManagement;
public
{ Public declarations }
end;
var
frmMain: TfrmMain;
implementation
{$R *.dfm}
uses Frame1, Frame2;
procedure TfrmMain.FormCreate(Sender: TObject);
begin
FFrame := TFramemanagement.Create;
end;
procedure TfrmMain.btnFrame1Click(Sender: TObject);
begin
FFrame.CreateGenericFrame(pnlFrames, TFrame(Frame1.TFra1));
end;
procedure TfrmMain.btnFrame2Click(Sender: TObject);
begin
FFrame.CreateGenericFrame(pnlFrames, TFrame(Frame2.TFra2));
end;
end.
此表单使用如下声明的接口:
unit FramesManagement;
interface
uses
Vcl.Forms, Vcl.StdCtrls, Vcl.ExtCtrls, Frame1, Frame2;
type
IFrameManagement = interface
['{A00E0D1B-3438-4DC4-9794-702E8302B567}']
procedure CreateGenericFrame(ParentPanel: TPanel; FrameName: TFrame);
end;
TFrameManagement = class(TInterfacedObject, IFrameManagement)
private
genericFrame: TFrame;
procedure CreateGenericFrame(ParentPanel: TPanel; FrameName: TFrame);
end;
implementation
procedure TFrameManagement.CreateGenericFrame(ParentPanel: TPanel;
FrameName: TFrame);
begin
genericFrame := FrameName.Create(ParentPanel);
genericFrame.Parent := ParentPanel;
end;
这里有两个框架。
第 1 帧:
unit Frame1;
interface
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,
System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs,
Vcl.StdCtrls;
type
TFra1 = class(TFrame)
txtFrame1: TStaticText;
txtFrameType: TStaticText;
lblFrameType: TLabel;
private
public
end;
implementation
{$R *.dfm}
end.
和第 2 帧:
unit Frame2;
interface
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,
System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs,
Vcl.StdCtrls;
type
TFra2 = class(TFrame)
txtFrame2: TStaticText;
txtFrameType: TStaticText;
lblFrameType: TLabel;
private
public
end;
implementation
{$R *.dfm}
end.
这是所有代码,但是当我 运行 应用程序并尝试创建第一帧或第二帧时,我收到如下错误:
我认为解决方案可能是使用泛型,但我不知道如何使用它们。我的想法是对的还是有另一种方法可以达到这个目标? 谁能帮帮我?
procedure TFrameManagement.CreateGenericFrame(ParentPanel: TPanel; FrameName: TFrame);
begin
genericFrame := FrameName.Create(ParentPanel);
genericFrame.Parent := ParentPanel;
end;
这里 FrameName
是一个实例,您正在调用该实例的构造函数。您没有按照您的意愿创建新实例。
您需要使用元 类。
type
TFrameClass = class of TFrame;
procedure TFrameManagement.CreateGenericFrame(ParentPanel: TPanel; FrameClass: TFrameClass);
begin
genericFrame := FrameClass.Create(ParentPanel);
genericFrame.Parent := ParentPanel;
end;
你可以这样称呼:
FFrame.CreateGenericFrame(pnlFrames, Frame2.TFra2);