讀取文本文件的值並將值寫入QDoubleSpinBox

Question

我想從文本文件中讀取字符串（數據）並將數據寫入QDoubleSpinBox。所以我用：

void GUIsubclassKuehniGUI::LoadDirectory() 
    { 
     QString loadedDirectory = QFileDialog::getExistingDirectory(this, 
                "/home",tr("Create Directory"), 
                QFileDialog::DontResolveSymlinks); 
     ui.PathDirectory -> setText(loadedDirectory); 

     QFileInfo GeoDat1 = loadedDirectory + "/1_geo.m4"; 
     QFileInfo GeoDat2 = loadedDirectory + "/2_geo.m4";   
     QString Value; 

     if (GeoDat1.exists() == true) 
     { 
      QFile GEO (loadedDirectory + "/1_geo.m4"); 

      if(GEO.open(QIODevice::ReadOnly | QIODevice::Text))  
      { 
       QTextStream Stream (&GEO); 
       QString Text; 
       do 
       { 
        Text = Stream.readLine(); 

        QString startWith = "start"; 
        QString endWith = "stop" ;          
        int start = Text.indexOf(startWith, 0, Qt::CaseInsensitive); 
        int end = Text.indexOf(endWith, Qt::CaseInsensitive);   

        if (start != -1)            
         Value = Text.mid(start + startWith.length(), end - (start + startWith.length())); 

qDebug() << Value << (start + startWith.length()) << (end - (start + startWith.length())); 


        double ValueNumber = Value.toDouble(); 
        ValueNumber = ui.ValueQDoubleSpinBox->value(); 
       } 
       while(!Text.isNull()); 
       GEO.close(); 
      } 
     } 
     else if (GeoDat2.exists() == true) 
     { 
      ... 
     } 
    } 

編譯時我沒有得到任何錯誤信息，但是當我使用的方法LoadDirectory的QString的「價值」與搜索的方法「的QString ::的indexOf」和「的QString ::中旬」文件「/1_geo.m4」存在我用QFileInfo :: exists（）驗證的內容沒有寫入QDoubleSpinBox「ValueQDoubleSpinBox」中。有人可以告訴我爲什麼它不起作用嗎？問候

Answer 1

恕我直言，下面幾行：

double ValueNumber = Value.toDouble(); 
ValueNumber = ui.ValueQDoubleSpinBox->value(); // get value from spinbox 

必須改爲：

double ValueNumber = Value.toDouble(); 
ui.ValueQDoubleSpinBox->setValue(ValueNumber); // set value of spinbox 

詳情：http://qt-project.org/doc/qt-4.8/qdoublespinbox.html#value-prop