我有一个2D数组QPushButton
,当用户点击它时,如何获得该按钮的索引?例如,当用户点击按钮a[2][3]
时,它会显示(2,3)
?
答案 0 :(得分:11)
示例如下所示:
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。
// 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"
在Qt 5和C ++ 11中,您应该使用仿函数为每个按钮生成自定义插槽。例如:
// 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();
}
QSignalMapper
几乎是为您想要的而设计的。它允许您将QObject*
映射到&#34;其他内容&#34;,就像一个字符串。例如:
#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();
}
您可以利用QWidget
是QObject
的事实。 QObjects有一个属性系统,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:
#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"
答案 1 :(得分:0)
一般情况下,你必须遍历数组并测试事件目标是否与每个元素相等,直到你得到正确的索引