无法显示 QDialog/QProgressbar

Question

我设计了一个应用程序是C++/Qt，用于在我的Mac和Android设备之间传输文件。

为此，我创建了一个类QDialog，如下所示：

对话框.cpp

Dialog::Dialog(QWidget *parent)
    : QWidget(parent)
{
}
void Dialog::CreateProgressBar() {
    ProgressDialog = new QWidget(this);
    ProgressDialog->setWindowTitle("Progress");
    ProgressLayout = new QVBoxLayout(this);
    ProgressIndicator = new QProgressBar();
    ProgressIndicator->resize(200,25);
    ProgressIndicator->setValue(0);
    ProgressIndicator->setOrientation(Qt::Horizontal);
    //connect(this,SIGNAL(ProgressBar(const uint64_t, const uint64_t, void const * const)),ProgressIndicator,SLOT(setValue(int)));
    CancelButton = new QPushButton();
    CancelButton->setFixedSize(25,25);
    CancelButton->setText("Cancel");
    CancelButton->setFlat(true);
    CancelButton->setAutoFillBackground(true);
    CancelButton->setStyleSheet("QPushButton { background-color : white;}");
    connect(CancelButton, SIGNAL(clicked()), this, SLOT(onCancelButtonAction()));
    ProgressLayout->addWidget(ProgressIndicator);
    ProgressLayout->addWidget(CancelButton);
    ProgressDialog->setLayout(ProgressLayout);
    ProgressDialog->show();
}
void Dialog::setValue(const uint64_t value) {
    ProgressIndicator->setValue(value);
}
void Dialog::DestroyProgressBar() {
    ProgressDialog->close();
}

对话.h

class Dialog : public QWidget
{
    Q_OBJECT
public:
    Dialog(QWidget *parent = 0);
    /* ProgressIndicator */
    //int ProgressBar(const uint64_t data_sent, const uint64_t data_total, void const * const data);
    void CreateProgressBar();
    void DestroyProgressBar();
    int createOverwriteDialogBox(char* filename);
    void setValue(const uint64_t value);
    void WaitBoxDialog();
    void DestroyWaitBoxDialog();
private:
    QWidget *ProgressDialog;
    QProgressBar *ProgressIndicator;
    QVBoxLayout *ProgressLayout;
    QPushButton *CancelButton;

为了显示它，我目前有一个名为wrapper的源代码.cpp它负责管理副本。

在

管理复制时，在整理 API LIBMTP_Send_File_to_File之前，我启动了方法实例化。

   Dialog *MyProgress = new Dialog();
MyProgress->CreateProgressBar();
genfile = LIBMTP_new_file_t();

   LIBMTP_Send_File_From_File(PulsDeviceMngr->device, strdup(AbsolutePath), genfile, NULL, NULL);//ProgressBar, MyProgress);
LIBMTP_destroy_file_t(genfile);

MyProgress->DestroyProgressBar();
//delete MyProgress;
}

我

仍然不明白为什么我看不到对话框。

Answer 1

我认为您需要两个线程，一个用于进行处理，另一个用于保持 GUI 运行。像这样：

#include <QFutureWatcher>
#include <QMetaObject>
#include <QtConcurrent/QtConcurrentRun>
void sendFile()
{
    LIBMTP_Send_File_From_File(PulsDeviceMngr->device, strdup(AbsolutePath), genfile, NULL, NULL);
    QMetaObject::invokeMethod(MyProgress, "setValue", Q_ARG(int, 50));
    LIBMTP_destroy_file_t(genfile);
}
MyProgress->CreateProgressBar();
QFutureWatcher<void> futureWatcher;
connect(futureWatcher, SIGNAL(finished()), MyProgress, SLOT(DestroyProgressBar()));
futureWatcher.setFuture(QtConcurrent::run(sendFile));

当然，你需要让setValue和DestroyProgressBar成为公共插槽。