如何知道哪些QLineEdit发出的editingFinished（）里面的信号处理程序？ [英] How to know which QLineEdit emitted the editingFinished() inside the signal handler?

问题描述

我想对几个类似的 QLineEdit 对象的用户输入实现自定义响应。我想创建一个 editingFinished（）或 textChanged（）信号的共同处理程序，并将其分配给所有< c $ c> QLineEdit s。但是，响应需要信号发送者的知识 - 例如，它必须用不同的颜色突出显示输入的文本。

如何知道发送者

您可以通过调用 QObject :: sender（），然后将此指针转换为QLineEdit。类似

  void MyClass :: onTextChanged（const QString& text）
 {
 QLineEdit * edit = qobject_cast< QLineEdit *>（sender（））; 
 if（edit）
 {
 //使用QLineEdit执行操作
} 
 else 
 {
 //只是为了确保没有错误连接信号
} 
} 
  

I want to implement a custom response to user input for several similar QLineEdit objects. I want to create a common handler of editingFinished() or textChanged() signal and assign it to all the QLineEdits. However, the response requires the knowledge of the sender of the signal - for example, it must highlight the entered text with different colors.

How do I know the sender of the signal inside it's handler?

解决方案

You can get pointer to sender with call to QObject::sender() and then cast this pointer to QLineEdit. Something like

void MyClass::onTextChanged(const QString& text)
{
  QLineEdit* edit = qobject_cast<QLineEdit*>(sender());
  if (edit)
  {
    // Do something with QLineEdit
  }
  else
  {
    // Just to make sure that you have not make mistake with connecting signals
  }
}

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