德爾福的TStringList查找方法無法找到項目

Question

我寫我自己的類來管理Android/iOS應用程序的翻譯和我產生了這個代碼。我將解釋下面的代碼，但它非常簡單和簡短。

unit Localization; 

interface 

uses 
System.Classes, System.SysUtils, Generics.Collections, Vcl.Dialogs; 

//this class represents a single language (Italian, French, German...) 
type 
TLanguage = class 
    private 
    FTranslationList: TDictionary<string, string>; 
    function localize(const aWordId: string): string; 
    public 
    constructor Create; 
    destructor Destroy; override; 
    //methods 
    procedure addWord(const aIndex, aWord: string); 
    procedure removeWord(const aIndex: string); 
end; 

//this is a "container", it gathers all the languages in one place 
type 
TLocalization = class 
    private 
    FLanguagesList: TObjectList<TLanguage>; 
    FLocaleList: TStringList; 
    function getLang(Index: string): TLanguage; 
    public 
    constructor Create; 
    destructor Destroy; override; 
    //methods 
    function localize(const aLocaleId: string; const aIndex: string): string; 
    procedure addLanguage(const localeId: string); 
    //property to manage the languages 
    property Locale[Index: string]: TLanguage read getLang; 
    property langCount: integer read getCount; 
end; 

implementation 

{ TLocalization } 

{ add a new language to the class. } 
{the localeId is a symbol like 'it' that represents the Italian language} 
procedure TLocalization.addLanguage(const localeId: string); 
begin 
//add the language to the languages container 
FLanguagesList.Add(TLanguage.Create); 
//add the representation of the language. 
FLocaleList.Add(localeId); 
end; 

constructor TLocalization.Create; 
begin 
FLanguagesList := TObjectList<TLanguage>.Create; 
FLocaleList := TStringList.Create; 
end; 

destructor TLocalization.Destroy; 
begin 
FLanguagesList.Free; 
FLocaleList.Free; 
inherited; 
end; 

//ERROR HERE 
function TLocalization.getLang(Index: string): TLanguage; 
var i: integer; 
begin 

{ I search the locale id (for example 'it') if it's in the list. } 
{ if it's in the list, I return the respective TLanguage object} 
if not(FLocaleList.Find(Index, i)) then 
    Result := FLanguagesList.Items[i] 
else 
    raise Exception.Create('Locale not found'); 

end; 

function TLocalization.localize(const aLocaleId, aIndex: string): string; 
var k: integer; 
begin 

k := 0; 

if not(FLocaleList.Find(aLocaleId, k)) then 
    raise Exception.Create('Locale not found.'); 

//ho trovato il locale, adesso basta cercare la parola 
Result := FLanguagesList.Items[k].localize(aIndex); 

end; 

{ TLanguage } 

procedure TLanguage.addWord(const aIndex, aWord: string); 
begin 
FTranslationList.Add(aIndex, aWord); 
end; 

constructor TLanguage.Create; 
begin 
FTranslationList := TDictionary<string, string>.Create; 
end; 

destructor TLanguage.Destroy; 
begin 
FTranslationList.Free; 
inherited; 
end; 

function TLanguage.localize(const aWordId: string): string; 
begin 

try 
    Result := FTranslationList.Items[aWordId]; 
except 
    Result := 'Not found.'; 
end; 

end; 

procedure TLanguage.removeWord(const aIndex: string); 
begin 
FTranslationList.Remove(aIndex); 
end; 

end. 

以上被用作代碼如下：

var a: TLocalization; 
begin 
    a := TLocalization.Create; 

    a.addLanguage('it'); 
    a.addLanguage('cse'); 
    a.Locale['it'].addWord('test', 'Ciao mondo!'); 
    a.Locale['cse'].addWord('test', 'fadfa ea!'); 

    ButtonSomething.Text := a.localize('it', test); 

end; 

的TLocalization類完成所有工作。正如你所看到的，我創建了變量a，然後我添加一個語言到這個類（這是使用字典/字符串列表在內部管理的）。

我可以使用Locale[Index: string]屬性訪問我已添加的語言，該屬性返回一個TLanguage，該類用於指示單個lang。在本地化方法的最後，我得到了我的翻譯。

---

奇怪的是，我總是得到錯誤'Locale not found'。任何想法？使用我發現這個調試器：

的FLocaleList有項目，但我已經測試了這一點，我想我做錯了什麼上線71（在這裏我使用查找功能）。我是否錯過了索引？

Answer 1

你的代碼邏輯是倒退。 Find()如果找到匹配則返回True，否則返回False。如果Find()返回False，則正在訪問Items[]，如果返回True則引發異常。您需要刪除not在if聲明：

function TLocalization.getLang(Index: string): TLanguage; 
var 
    i: integer; 
begin 
    { I search the locale id (for example 'it') if it's in the list. } 
    { if it's in the list, I return the respective TLanguage object} 
    if FLocaleList.Find(Index, i) then // <-- HERE 
    Result := FLanguagesList.Items[i] 
    else 
    raise Exception.Create('Locale not found'); 
end; 

但是，更重要的是，Find() documentation說：

注：僅使用Find與有序列表。對於未排序的列表，請使用IndexOf方法。

您的列表未排序，因爲Sorted屬性默認爲false。因此，使用IndexOf()代替：

function TLocalization.getLang(Index: string): TLanguage; 
var 
    i: integer; 
begin 
    { I search the locale id (for example 'it') if it's in the list. } 
    { if it's in the list, I return the respective TLanguage object} 
    i := FLocaleList.IndexOf(Index); 
    if i <> -1 then 
    Result := FLanguagesList.Items[i] 
    else 
    raise Exception.Create('Locale not found'); 
end;