Question

我试图在qt中添加进度条但出现以下错误：

error: no matching function for call to 'map(QVector<int>&, <unresolved overloaded function type>)'
      futureWatcher.setFuture(QtConcurrent::map(vector, spin));

代码如下：

using namespace QtConcurrent;

const int iterations = 20;

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    QVector<int> vector;
    for (int i = 0; i < iterations; ++i)
        vector.append(i);
    QProgressDialog dialog;
    dialog.setLabelText(QString("Progressing using %1 thread(s)...").arg(QThread::idealThreadCount()));
    QFutureWatcher<void> futureWatcher;

    QObject::connect(&futureWatcher, SIGNAL(progressRangeChanged(int,int)), &dialog, SLOT(setRange(int,int)));
     QObject::connect(&futureWatcher, SIGNAL(progressValueChanged(int)), &dialog, SLOT(setValue(int)));

     futureWatcher.setFuture(QtConcurrent::map(vector, spin));

  dialog.exec();
}

void MainWindow::spin(int &iteration)
{
    const int work =1000 * 1000 * 40;
    volatile int v =0;
    for(int j = 0; j< work; j++)
        ++v;
    qDebug()<< "iteration" <<iteration <<"in thread"<<QThread::currentThreadId();
}

我正在使用Qt5.2.1。无法识别错误。请帮我解决错误。

Answer 1

在这一行

futureWatcher.setFuture(QtConcurrent::map(vector, spin));

你应该指定spin函数的类名，并使用你的类对象绑定spin，使用ex。 std::bind。或者您也可以使用全局功能。

添加进度条时出错

1 个答案: