jpf*_*ius 10 delphi configuration-files rtti
我会自己回答这个问题,但如果你比我快,或者你不喜欢我的解决方案,请随时提供你的答案.我想出了这个想法,并希望对此有一些看法.
目标:一个可读的配置类(如INI文件),但无需编写(并在添加新配置项后进行调整)加载和保存方法.
我想创建一个类
TMyConfiguration = class (TConfiguration)
...
property ShowFlags : Boolean read FShowFlags write FShowFlags;
property NumFlags : Integer read FNumFlags write FNumFlags;
end;
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调用TMyConfiguration.Save(继承自TConfiguration)应该创建一个类似的文件
[Options]
ShowFlags=1
NumFlags=42
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问题:最好的方法是什么?
这是我提出的解决方案.
我有一个基类
TConfiguration = class
protected
type
TCustomSaveMethod = function (Self : TObject; P : Pointer) : String;
TCustomLoadMethod = procedure (Self : TObject; const Str : String);
public
procedure Save (const FileName : String);
procedure Load (const FileName : String);
end;
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Load方法如下所示(相应地保存方法):
procedure TConfiguration.Load (const FileName : String);
const
PropNotFound = '_PROP_NOT_FOUND_';
var
IniFile : TIniFile;
Count : Integer;
List : PPropList;
TypeName, PropName, InputString, MethodName : String;
LoadMethod : TCustomLoadMethod;
begin
IniFile := TIniFile.Create (FileName);
try
Count := GetPropList (Self.ClassInfo, tkProperties, nil) ;
GetMem (List, Count * SizeOf (PPropInfo)) ;
try
GetPropList (Self.ClassInfo, tkProperties, List);
for I := 0 to Count-1 do
begin
TypeName := String (List [I]^.PropType^.Name);
PropName := String (List [I]^.Name);
InputString := IniFile.ReadString ('Options', PropName, PropNotFound);
if (InputString = PropNotFound) then
Continue;
MethodName := 'Load' + TypeName;
LoadMethod := Self.MethodAddress (MethodName);
if not Assigned (LoadMethod) then
raise EConfigLoadError.Create ('No load method for custom type ' + TypeName);
LoadMethod (Self, InputString);
end;
finally
FreeMem (List, Count * SizeOf (PPropInfo));
end;
finally
FreeAndNil (IniFile);
end;
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基类可以为delphi默认类型提供加载和保存方法.然后我可以为我的应用程序创建一个配置,如下所示:
TMyConfiguration = class (TConfiguration)
...
published
function SaveTObject (P : Pointer) : String;
procedure LoadTObject (const Str : String);
published
property BoolOption : Boolean read FBoolOption write FBoolOption;
property ObjOption : TObject read FObjOption write FObjOption;
end;
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自定义保存方法的示例:
function TMyConfiguration.SaveTObject (P : Pointer) : String;
var
Obj : TObject;
begin
Obj := TObject (P);
Result := Obj.ClassName; // does not make sense; only example;
end;
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我将XML用于我的所有应用程序作为配置方法.它是:
我有一个XML库,可以非常轻松地读取或修改配置,甚至无需查看缺失的值.现在,您还可以将XML映射到应用程序内的类,以便在速度成为问题时更快地访问,或者不断读取某些值.
我发现其他配置方法更不可选: