有關SIGNAL / SLOT qt4的問題

Question

我創建了一個GUI，該GUI涉及從一個ComboBox（ Evaluation_box ）中選擇主題，從而將與該特定主題相關的所有主題加載到另一個ComboBox（ sequence_combo_box ）中。

用於SIGNAL / SLOT的代碼如下

  connect(ui_.evaluation_box, SIGNAL(currentIndexChanged(QString)), ui_.sequence_combo_box, SLOT(readSequenceFile(char *,char *,struct dirent *)));   

但是，這樣做時，我收到以下錯誤消息：

Object::connect: No such slot QComboBox::readSequenceFile(char *,char *,struct dirent *)
Object::connect:  (sender name:   'evaluation_box')
Object::connect:  (receiver name: 'sequence_combo_box')

頭文件包括以下內容：

#ifndef rqt_get_sequence_feeder__GetSequenceFeeder_H
#define rqt_get_sequence_feeder__GetSequenceFeeder_H

#include <rqt_gui_cpp/plugin.h>

#include <ui_get_sequence_feeder.h>
#include <dirent.h>
#include <image_transport/image_transport.h>    
#include <sensor_msgs/Image.h>    
#include <opencv2/core/core.hpp>    
#include <QImage>
#include <QList>
#include <QMutex>
#include <QString>
#include <QSize>
#include <QWidget>
#include <vector>

    namespace rqt_get_sequence_feeder {

    class GetSequenceFeeder
      : public rqt_gui_cpp::Plugin
     {

      Q_OBJECT
        public:
           GetSequenceFeeder();

        protected slots:            
          virtual void onFrameChanged(int);
          virtual void readSequenceFile(char *folder,char *sequence,struct dirent *select);
                                          .
                                          .
                                          .
       protected:    
         Ui::GetSequenceFeederWidget ui_;

     };
    }

.cpp如下：

using namespace std;
namespace rqt_get_sequence_feeder {

GetSequenceFeeder::GetSequenceFeeder()
  : rqt_gui_cpp::Plugin()
  , widget_(0)
{
  setObjectName("GetSequenceFeeder");
}


void GetSequenceFeeder::initPlugin(qt_gui_cpp::PluginContext& context)
{
    connect(ui_.evaluation_box, SIGNAL(currentIndexChanged(QString)),ui_.sequence_combo_box, SLOT(readSequenceFile(char *,char *,struct dirent *)));   
                                      .
                                      .
                                      .
}

void GetSequenceFeeder::readSequenceFile(char *folder ,char *sequenceFile,struct dirent *select)
{
                                     .
                                     .
                                     .
}

我有功能readSequenceFile(char *folder,char *sequence,struct dirent *select); 在標頭文件中聲明為protected slots:我還嘗試了將其聲明為public slot: ，但無效。 我不明白我在做什么錯。

Answer 1

根據您的錯誤消息，您的ui_.sequence_combo_box是一個QComboBox ，並且顯然QComboBox沒有名為readSequenceFile的插槽函數。
ui_.sequence_combo_box應該是繼承QComboBox的類