获取二维数组QPushButton上QPushButton的索引 [英] Get index of QPushButton on 2D array QPushButton

问题描述

我有2D数组 QPushButton ，当用户单击按钮时如何获取按钮的索引？例如，当用户单击按钮 a [2] [3] 时，将显示（2,3）吗？

I have an 2D array QPushButton, how can I get index of the button when user clicks on its? such as When user clicks on the button a[2][3] it will show (2,3) ?

推荐答案

示例如下：

您可以为按钮指定唯一的对象名称。理想情况下，名称应该是有效的C ++标识符。

You can give your buttons unique object names. The names should ideally be valid C++ identifiers.

// https://github.com/KubaO/stackoverflown/tree/master/questions/button-grid-22641306
#include <QtGui>
#if QT_VERSION_MAJOR >= 5
#include <QtWidgets>
#endif

struct Display : QLabel {
   Q_SLOT void onClicked() {
      auto const elements = sender()->objectName().split('_');
      auto const i = elements.at(1).toInt();
      auto const j = elements.at(2).toInt();
      setText(QString{"(%1,%2)"}.arg(i).arg(j));
   }
   Q_OBJECT
};

int main(int argc, char *argv[])
{
   QApplication a{argc, argv};
   QWidget window;
   QGridLayout layout{&window};
   QVarLengthArray<QPushButton, 12> buttons(12);
   Display display;

   const int rows = 4, columns = 3;
   for (int i = 0; i < rows; ++ i)
      for (int j = 0; j < columns; ++j) {
         auto & button = buttons[i*columns+j];
         button.setText(QString{"(%1,%2)"}.arg(i).arg(j));
         button.setObjectName(QString{"buton_%1_%2"}.arg(i).arg(j));
         layout.addWidget(&button, i, j);
         display.connect(&button, SIGNAL(clicked()), SLOT(onClicked()));
      }
   layout.addWidget(&display, rows, 0, 1, columns);

   window.show();
   return a.exec();
}
#include "main.moc"

Qt 5-使用Lambdas

在Qt 5和C ++ 11中，应该使用仿函数为每个按钮动态生成自定义插槽。例如：

Qt 5 - Using Lambdas

In Qt 5 and C++11, you should use functors to generate custom slot for each button, on the fly. For example:

// https://github.com/KubaO/stackoverflown/tree/master/questions/button-grid-22641306
#include <QtWidgets>

int main(int argc, char *argv[])
{
   QApplication a{argc, argv};
   QWidget window;
   QGridLayout layout{&window};
   QVarLengthArray<QPushButton, 12> buttons(12);
   QLabel display;

   const int rows = 4, columns = 3;
   for (int i = 0; i < rows; ++ i)
      for (int j = 0; j < columns; ++j) {
         auto text = QStringLiteral("(%1,%2)").arg(i).arg(j);
         auto & button = buttons[i*columns+j];
         button.setText(text);
         layout.addWidget(&button, i, j);
         QObject::connect(&button, &QPushButton::clicked, [&display, text] {
            display.setText(text);
         });
      }
   layout.addWidget(&display, rows, 0, 1, columns);

   window.show();
   return a.exec();
}

Qt 4/5-使用QSignalMapper

QSignalMapper 几乎是为您想要的而设计的。它使您可以将 QObject * 映射为其他，例如字符串。例如：

Qt 4/5 - Using QSignalMapper

QSignalMapper is pretty much designed for what you want. It lets you map a QObject* to "something else", like a string. For example:

#include <QtGui>
#if QT_VERSION_MAJOR >= 5
#include <QtWidgets>
#endif

int main(int argc, char *argv[])
{
   QApplication a{argc, argv};
   QSignalMapper mapper;
   QWidget window;
   QGridLayout layout{&window};
   QVarLengthArray<QPushButton, 12> buttons(12);
   QLabel display;

   const int rows = 4, columns = 3;
   for (int i = 0; i < rows; ++ i)
      for (int j = 0; j < columns; ++j) {
         auto text = QString{"(%1,%2)"}.arg(i).arg(j);
         auto & button = buttons[i*columns+j];
         button.setText(text);
         layout.addWidget(&button, i, j);
         mapper.connect(&button, SIGNAL(clicked()), SLOT(map()));
         mapper.setMapping(&button, text);
      }
   display.connect(&mapper, SIGNAL(mapped(QString)), SLOT(setText(QString)));
   layout.addWidget(&display, rows, 0, 1, columns);

   window.show();
   return a.exec();
}

Qt 4/5-使用物业系统

您可以利用 QWidget 是 QObject 的事实。 QObject具有属性系统，因此您可以将每个按钮的索引设置为属性，然后在连接到 clicked（）信号的插槽中检索它。例如：

Qt 4/5 - Using the Property System

You can leverage the fact that a QWidget is a QObject. QObjects have a property system, so you can set each button's index as a property, and then retrieve it in the slot connected to the clicked() signal. For example:

#include <QtGui>
#if QT_VERSION_MAJOR >= 5
#include <QtWidgets>
#endif

const char kIndex[] = "index";
struct Display : QLabel {
   Q_SLOT void onClicked() {
      setText(sender()->property(kIndex).toString());
   }
   Q_OBJECT
};

int main(int argc, char *argv[])
{
   QApplication a{argc, argv};
   QWidget window;
   QGridLayout layout{&window};
   QVarLengthArray<QPushButton, 12> buttons(12);
   Display display;

   const int rows = 4, columns = 3;
   for (int i = 0; i < rows; ++ i)
      for (int j = 0; j < columns; ++j) {
         auto index = QString{"(%1,%2)"}.arg(i).arg(j);
         auto & button = buttons[i*columns+j];
         button.setText(index);
         button.setProperty(kIndex, index);
         layout.addWidget(&button, i, j);
         display.connect(&button, SIGNAL(clicked()), SLOT(onClicked()));
      }
   layout.addWidget(&display, rows, 0, 1, columns);

   window.show();
   return a.exec();
}
#include "main.moc"

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