我有这样的课程
TuserClass = class
private
FUtilisateurCode: string;
FUtilisateurCle: string;
public
procedure SetCodeInt(ACode: string; AValue: string);
published
[CodeInt('2800')]
property UtilisateurCode: String read FUtilisateurCode write FUtilisateurCode;
[CodeInt('2801')]
property UtilisateurCle: String read FUtilisateurCle write FUtilisateurCle;
end;
procedure TuserClass.SetCodeInt(ACode: string; AValue: string);
begin
// what I want to is making this by RTTI to set good value to good CodeInt
if ACode = '2800' then FutilisateurCode := AValue
else if ACode = '2801' then FUtilisateurCle := AValue;
end;
我想使用我的SetCodeInt程序填充我的属性值,但我有问题。 我该怎么办?
答案 0 :(得分:6)
您需要一个自定义属性类:
type
CodeIntAttribute = class(TCustomAttribute)
private
FValue: Integer;
public
constructor Create(AValue: Integer);
property Value: Integer read FValue;
end;
....
constructor CodeIntAttribute.Create(AValue: Integer);
begin
inherited Create;
FValue := AValue;
end;
我选择将值设为一个看起来比字符串更合适的整数。
然后定义如下属性:
[CodeInt(2800)]
property UtilisateurCode: string read FUtilisateurCode write FUtilisateurCode;
[CodeInt(2801)]
property UtilisateurCle: string read FUtilisateurCle write FUtilisateurCle;
最后SetCodeInt
的实施是:
procedure TUserClass.SetCodeInt(ACode: Integer; AValue: string);
var
ctx: TRttiContext;
typ: TRttiType;
prop: TRttiProperty;
attr: TCustomAttribute;
codeattr: CodeIntAttribute;
begin
typ := ctx.GetType(ClassType);
for prop in typ.GetProperties do
for attr in prop.GetAttributes do
if attr is CodeIntAttribute then
if CodeIntAttribute(attr).Value=ACode then
begin
prop.SetValue(Self, TValue.From(AValue));
exit;
end;
raise Exception.CreateFmt('Property with code %d not found.', [ACode]);
end;