Question

我有一个耗时的计算，取决于双精度值。为此，我创建了一个GUI，可以在其中使用QDoubleSpinBox来设置计算值。双旋转框QDoubleSpinBox::valueChanged(double)信号连接到插槽，该插槽使用QtConcurrent::run在新线程中开始大量计算。问题是，当我添加进度条时，当进度条出现时，双旋转框会自动填充其内容（零填充直到小数位数）。我的感觉是，这是因为双旋转框失去了焦点（即进度条是选定的小部件）。

我的问题是：

如何显示进度条并制作双旋转框不能用零填充其余的小数？

This video显示了如何在未显示进度条时继续编辑双旋转框，而在显示进度条时，双旋转框将其精度填充为零。这是当前的行为，而不是所需的行为。理想的情况是计算完成后，双旋转框没有自动用零填充其空的小数位。这是用于视频的代码（在GitHub中完全可用）：

标题

class DoubleSpinboxHeavyComputation : public QWidget
{
  Q_OBJECT

public:
  explicit DoubleSpinboxHeavyComputation(QWidget *parent = nullptr);
  ~DoubleSpinboxHeavyComputation();

signals:

  void computationDone();

  void progressSignal(int progress_state);

private slots:
  void startHeavyComputationInThread();

  void heavyComputation();

private:
  Ui::DoubleSpinboxHeavyComputation *ui;
  int n_ = 0;
};

实施

DoubleSpinboxHeavyComputation::DoubleSpinboxHeavyComputation(QWidget *parent)
  : QWidget(parent), ui(new Ui::DoubleSpinboxHeavyComputation)
{
  ui->setupUi(this);
  connect(ui->doubleSpinBox, QOverload<double>::of(&QDoubleSpinBox::valueChanged), this,
          &DoubleSpinboxHeavyComputation::startHeavyComputationInThread);
}

DoubleSpinboxHeavyComputation::~DoubleSpinboxHeavyComputation()
{
  delete ui;
}

void DoubleSpinboxHeavyComputation::startHeavyComputationInThread()
{
  if (ui->checkBox->isChecked())
  {
    QProgressDialog *progress = new QProgressDialog("Computing", "", 0, 0, this);
    progress->setWindowTitle(windowTitle());
    progress->setWindowFlags((progress->windowFlags() | Qt::CustomizeWindowHint) &
                             ~Qt::WindowCloseButtonHint);  // Hide close button
    progress->setWindowModality(Qt::WindowModal);
    progress->setCancelButton(nullptr);
    progress->setMaximum(1000);
    progress->show();
    connect(this, &DoubleSpinboxHeavyComputation::progressSignal, progress, &QProgressDialog::setValue);
    connect(this, &DoubleSpinboxHeavyComputation::computationDone, progress, &QProgressDialog::close);
    connect(this, &DoubleSpinboxHeavyComputation::computationDone, progress, &QProgressDialog::deleteLater);
  }
  QtConcurrent::run(this, &DoubleSpinboxHeavyComputation::heavyComputation);
}

void DoubleSpinboxHeavyComputation::heavyComputation()
{
  int current_n = n_;
  ++n_;
  qDebug() << "Start computation " << current_n;
  for (int i = 0; i < 1000; i++)
  {
    emit progressSignal(i);
    usleep(1000);
  }
  qDebug() << "End computation" << current_n;
  emit computationDone();
}

Answer 1

好像您需要继承<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery-confirm/3.3.2/jquery-confirm.min.js"></script> <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.2/js/bootstrap.min.js"></script> <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/jquery-confirm/3.3.2/jquery-confirm.min.css"> <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.2/css/bootstrap.min.css"> <div class="form-row"> <div class="form-group col-xs-6 col-sm-6 col-md-6 col-lg-2"> <label for="nameInput">First Name</label> <div class="input-group"> <input type="text" class="form-control" aria-label="Text input with dropdown button" name="nameInput" id="nameInput"> </div> </div> <div class="form-group col-xs-6 col-sm-6 col-md-6 col-lg-2"> <label for="lastNameInput">Last Name</label> <div class="input-group"> <input type="tel" class="form-control" aria-label="Text input with dropdown button" name="lastNameInput" id="lastNameInput"> </div> </div> <div class="form-group col-xs-6 col-sm-6 col-md-6 col-lg-2"> <label for="classInput">Class</label> <div class="input-group"> <input type="text" class="form-control" aria-label="Text input with dropdown button" name="classInput" id="classInput"> </div> </div> </div> <button type="button" class="commonButton" id="save"> Save </button>的子类并重新实现QDoubleSpinbox方法

textFromValue

但这会破坏Spinbox的默认class NumericEdit : public QDoubleSpinBox { Q_OBJECT public: NumericEdit(QWidget *p_parent = nullptr); QString textFromValue(double val) const; }; QString NumericEdit::textFromValue(double val) const { //default converting // return QString::number(val); //converting with a local representation QLocale locale; return locale.toString(val); }和preffix功能

Qt双旋转盒在处理值更改时自动填充

1 个答案: