tr字符串的梗

工作问题总结
声明：应用程序代码为前人所写，仅仅只是维护代码，暂且不论代码风格瑕疵。
结论：
使用tr“包”起来的字符串，可能会被翻译为不同的语言，此时，应用程序在不同语言环境下可能会表现BUG。
1.问题及源码追溯过程
  1 // 应用程序调用函数1
  2 void WinHelpManual::openFunction(QString func)
  3 {
  4     QWebPage *webPage = m_view_list.page();
  5     QWebFrame *webFrame = webPage->frameAt(QPoint(0, 0));
  6     QWebElement webElement = webFrame->documentElement();
  7     webElement.evaluateJavaScript(func);
  8 }
  9 // 应用程序调用函数2
 10 void WinHelpManual::openUrl()
 11 {
 12     QString Html = m_view_list.selectedHtml();
 13     QString strUrlExp = "outline_[0-9]*.htm";
 14     QRegExp urlRegExp(strUrlExp, Qt::CaseSensitive);
 15     if (urlRegExp.indexIn(Html) != -1)
 16     {
 17         QString strWebUrl = urlRegExp.cap(0);  // 匹配到的url
 18         m_view_contents.setUrl(QUrl(m_path + strWebUrl));
 19     }
 20 }
 21 // 应用程序调用函数3
 22 bool WinHelpManual::event(QEvent *event)
 23 {
 24     if (event->type() == QEvent::KeyRelease)
 25     {
 26         QKeyEvent *ke = static_cast<QKeyEvent*> (event);
 27         if (ke->modifiers() == PANEL_MODIFIER)
 28         {
 29             static int Ekey;
 30             if (ke->key() == PANEL_BAR || ke->key() == PANEL_WAVE || ke->key() == PANEL_NUMERIC || ke->key() == PANEL_VECTOR || 
 31                 ke->key() == PANEL_MARK || ke->key() == PANEL_ITEM || ke->key() == PANEL_FORM || ke->key() == PANEL_USER || 
 32                 ke->key() == PANEL_VOLTRANGE_CLOCKWISE || ke->key() == PANEL_VOLTRANGE_ANTICLOCKWISE || ke->key() == PANEL_VOLTRANGE_AUTO
 33                 || ke->key() == PANEL_CURRRANGE_CLOCKWISE || ke->key() == PANEL_CURRRANGE_ANTICLOCKWISE || ke->key() == PANEL_CURRANGE_AUTO
 34                 || ke->key() == PANEL_EXT || ke->key() == PANEL_ACCURATE || ke->key() == PANEL_UTILITY || ke->key() == PANEL_MEASURRE
 35                 || ke->key() == PANEL_OTHERS || ke->key() == PANEL_SOURCE || ke->key() == PANEL_FILE || ke->key() == PANEL_INFO 
 36                 || ke->key() == PANEL_IMAGESAVE || ke->key() == PANEL_HOLD || ke->key() == PANEL_SINGLE || ke->key() == PANEL_STROE 
 37                 || ke->key() == PANEL_INTEG || ke->key() == PANEL_LOCALLOCK)
 38             {
 39                 openFunction();
 40             }
 41             m_view_list.page()->findText("");//清除
 42             switch (ke->key())
 43             {
 44             case PANEL_ESC:
 45             case PANEL_HELP:
 46                 hide();
 47                 return true;
 48             case PANEL_BAR:
 49             {
 50                 Ekey = PANEL_BAR;
 51                 m_view_list.page()->findText(tr("Bar Graph Display(Bar)"));
 52             }
 53             break;
 54             case PANEL_WAVE:
 55             {
 56                 Ekey = PANEL_WAVE;
 57                 m_view_list.findText(tr("Waveform Display(WAVE)"));
 58             }
 59             break;
 60             case PANEL_NUMERIC:
 61             {
 62                 Ekey = PANEL_NUMERIC;
 63                 m_view_list.findText(tr("Numetic Data Display(NUMERIC)"));
 64             }
 65             break;
 66             case PANEL_VECTOR:
 67                 Ekey = PANEL_VECTOR;
 68                 m_view_list.findText(tr("Vector Display(Vector)"));
 69                 break;
 70             case PANEL_MARK:
 71             {
 72                 switch (Ekey)
 73                 {
 74                 case PANEL_BAR:
 75                     m_view_list.findText(tr("Bar Display Mark (MARK)"));
 76                     break;
 77                 case PANEL_WAVE:
 78                     m_view_list.findText(tr("Waveform Display Mark(MARK)"));
 79                     break;
 80                 default:
 81                     break;
 82                 }
 83             }
 84             break;
 85             case PANEL_ITEM:
 86             {
 87                 switch (Ekey)
 88                 {
 89                 case PANEL_BAR:
 90                     m_view_list.findText(tr("Bar Display Item (ITEM)"));
 91                     break;
 92                 case PANEL_WAVE:
 93                     m_view_list.findText(tr("Waveform Display Item(ITEM)"));
 94                     break;
 95                 case PANEL_NUMERIC:
 96                     m_view_list.findText(tr("Numetic Display Item(ITEM)"));
 97                     break;
 98                 case PANEL_VECTOR:
 99                     m_view_list.findText(tr("Vector Display Item(ITEM)"));
100                     break;
101                 default:
102                     break;
103                 }
104             }
105             break;
106             case PANEL_FORM:
107             {
108                 switch (Ekey)
109                 {
110                 case PANEL_BAR:
111                     m_view_list.findText(tr("Bar Display Format(FORM)"));
112                     break;
113                 case PANEL_WAVE:
114                     m_view_list.findText(tr("Waveform Display Format(FORM)"));
115                     break;
116                 case PANEL_NUMERIC:
117                     m_view_list.findText(tr("Numetic Display Format(FORM)"));
118                     break;
119                 case PANEL_VECTOR:
120                     m_view_list.findText(tr("Vector Display Format(FORM)"));
121                     break;
122                 default:
123                     break;
124                 }
125             }
126             break;
127             case PANEL_USER:
128                 m_view_list.findText(tr("Numetic Data Display(NUMERIC)"));
129                 break;
130             case PANEL_TAB:
131                 if (m_view_contents.hasFocus())
132                 {
133                     m_view_contents.setFocusPolicy(Qt::NoFocus);
134                     m_view_list.setFocus();
135                     p_curWebView = &m_view_list;
136                     repaint();
137                 }
138                 else if (m_view_list.hasFocus())
139                 {
140                     m_view_list.setFocusPolicy(Qt::NoFocus);
141                     m_view_contents.setFocus();
142                     p_curWebView = &m_view_contents;
143                     repaint();
144                 }
145                 break;
146             case PANEL_VOLTRANGE_CLOCKWISE:
147             case PANEL_VOLTRANGE_ANTICLOCKWISE:
148                 m_view_list.findText(tr("Voltage Range(RANGE UP/DOWN (V))"));
149                 break;
150             case PANEL_VOLTRANGE_AUTO:
151                 m_view_list.findText(tr("Auto Voltage Range(AUTO (V))"));
152                 break;
153             case PANEL_CURRRANGE_CLOCKWISE:
154             case PANEL_CURRRANGE_ANTICLOCKWISE:
155                 m_view_list.findText(tr("Current Range (RANGE UP/DOWN (A))"));
156                 break;
157             case PANEL_CURRANGE_AUTO:
158                 m_view_list.findText(tr("Auto Current Range(AUTO (A))"));
159                 break;
160             case PANEL_EXT:
161                 m_view_list.findText(tr("External Current Sensor Range (EXT SENSOR; option)"));
162                 break;
163             case PANEL_ACCURATE:
164                 m_view_list.findText(tr("Line Filter(LINE FILTER)"));
165                 break;
166             case PANEL_UTILITY:
167                 m_view_list.findText(tr("Utility (UTILITY)"));
168                 break;
169             case PANEL_MEASURRE:
170                 m_view_list.findText(tr("Computation(MEASURE)"));
171                 break;
172             case PANEL_OTHERS:
173                 m_view_list.findText(tr("Combination Display (COMBINE)"));
174                 break;
175             case PANEL_SOURCE:
176                 m_view_list.findText(tr("Measurement period(SYNC SOURCE)"));
177                 break;
178             case PANEL_FILE:
179                 m_view_list.findText(tr("File(File)"));
180                 break;
181             case PANEL_INFO:
182                 m_view_list.findText(tr(""));
183                 break;
184             case PANEL_IMAGESAVE:
185                 m_view_list.findText(tr("Screen capture function (Image )"));
186                 break;
187             case PANEL_HOLD:
188                 m_view_list.findText(tr("Holding Measured Values(HOLD)"));
189                 break;
190             case PANEL_SINGLE:
191                 m_view_list.findText(tr("Single Measurement(SINGLE)"));
192                 break;
193             case PANEL_STROE:
194                 m_view_list.findText(tr("Data Storage"));
195                 break;
196             case PANEL_INTEG:
197                 m_view_list.findText(tr("Integrated Power(Watt hours)"));
198                 break;
199             case PANEL_LOCALLOCK:
200                 m_view_list.findText(tr("Touch Unlock"));
201                 break;
202             default:
203                 return true;
204             }
205             openUrl();
206         }
207     }
208     return QWidget::event(event);
209 }
210 // QWebView page() 接口源码
211 QWebPage *QWebView::page() const
212 {
213     if (!d->page) 
214     {
215         QWebView *that = const_cast<QWebView *>(this);
216         that->setPage(new QWebPage(that));
217     }
218     return d->page;
219 }
220 // QWebView findText() 接口源码
221 bool QWebView::findText(const QString &subString, QWebPage::FindFlags options)
222 {
223     if (d->page)
224     {
225         return d->page->findText(subString, options);
226     }
227     return false;
228 }
229 // QWebPage findText() 接口源码
230 bool QWebPage::findText(const QString &subString, FindFlags options)
231 {
232     return d->findText(subString, static_cast<QWebPageAdapter::FindFlag>(options.operator int()));
233 }
234 // QWebPagePrivate findText() 接口源码
235 bool QWebPageAdapter::findText(const QString& subString, FindFlag options)
236 {
237     ::WebCore::FindOptions webCoreFindOptions = 0;
238 
239     if (!(options & FindCaseSensitively))
240     {
241         webCoreFindOptions |= WebCore::CaseInsensitive;
242     }
243 
244     if (options & FindBackward)
245     {
246         webCoreFindOptions |= WebCore::Backwards;
247     }
248 
249     if (options & FindWrapsAroundDocument)
250     {
251         webCoreFindOptions |= WebCore::WrapAround;
252     }
253 
254     if (options & FindAtWordBeginningsOnly)
255     {
256         webCoreFindOptions |= WebCore::AtWordStarts;
257     }
258 
259     if (options & TreatMedialCapitalAsWordBeginning)
260     {
261         webCoreFindOptions |= WebCore::TreatMedialCapitalAsWordStart;
262     }
263 
264     if (options & FindBeginsInSelection)
265     {
266         webCoreFindOptions |= WebCore::StartInSelection;
267     }
268 
269     if (options & HighlightAllOccurrences)
270     {
271         if (subString.isEmpty()) 
272         {
273             page->unmarkAllTextMatches();
274             return true;
275         }
276 
277         return page->markAllMatchesForText(subString, webCoreFindOptions, /*shouldHighlight*/ true, /*limit*/ 0);
278     }
279 
280     if (subString.isEmpty()) 
281     {
282         page->mainFrame()->selection()->clear();
283         Frame* frame = page->mainFrame()->tree()->firstChild();
284         while (frame)
285         {
286             frame->selection()->clear();
287             frame = frame->tree()->traverseNextWithWrap(false);
288         }
289     }
290 
291     return page->findString(subString, webCoreFindOptions);
292 }
293 // Page findString() 接口源码
294 bool Page::findString(const String& target, FindOptions options)
295 {
296     if (target.isEmpty() || !mainFrame())
297     {
298         return false;
299     }
300 
301     bool shouldWrap = options & WrapAround;
302     
303     Frame* frame = focusController()->focusedOrMainFrame();
304     Frame* startFrame = frame;
305     do 
306     {
307         if (frame->editor().findString(target, (options & ~WrapAround) | StartInSelection)) 
308         {
309             if (frame != startFrame)
310             {
311                 startFrame->selection()->clear();
312             }
313 
314             focusController()->setFocusedFrame(frame);
315             return true;
316         }
317         frame = incrementFrame(frame, !(options & Backwards), shouldWrap);
318     } while (frame && frame != startFrame);
319 
320     // Search contents of startFrame, on the other side of the selection that we did earlier.
321     // We cheat a bit and just research with wrap on
322     if (shouldWrap && !startFrame->selection()->isNone()) 
323     {
324         bool found = startFrame->editor().findString(target, options | WrapAround | StartInSelection);
325         focusController()->setFocusedFrame(frame);
326         return found;
327     }
328 
329     return false;
330 }
331 // Page mainFrame() 成员方法源码
332 Frame* mainFrame() const { return m_mainFrame.get(); }
333 // Editor findString() 成员方法源码
334 bool Editor::findString(const String& target, FindOptions options)
335 {
336     VisibleSelection selection = m_frame->selection()->selection();
337     RefPtr<Range> resultRange = rangeOfString(target, selection.firstRange().get(), options);
338     if (!resultRange)
339     {
340         return false;
341     }
342 
343     m_frame->selection()->setSelection(VisibleSelection(resultRange.get(), DOWNSTREAM));
344     m_frame->selection()->revealSelection();
345     return true;
346 }
2.问题原因
tr翻译后导致字符串查找失败。
如上实例，因为tr“包”起来的字符串被翻译为不同语言，但是每次与之比较匹配的字符串始终为英语版本。
所以，总出现匹配失败的异常，导致调试排除浪费很长时间，在此特别备录。
Good Good Study, Day Day Up.
顺序选择循环总结