QT, add the picture on the left side to lineEdit

Adding pictures on the left side of lineEdit is often used in login input, search input and other scenarios, here is a record

1. How to add

//对lineEdit左侧嵌入图片

QAction *action = new QAction(this);
action->setIcon(QIcon(":/QQ_Image_touming/email.png"));
ui->lineEdit->addAction(action,QLineEdit::LeadingPosition);


        //这段代码中，我们创建了一个QAction并设置其图标，然后通过addAction()方法将该QAction添加到QLineEdit控件的左侧。
        //请注意，第二个参数指定添加的位置，这里我们使用了QLineEdit::LeadingPosition以在最左侧添加图像

Effect:

Before setting:

                                                     

 

After setting:

 

 

 

2, How to achieve image scaling (generally not used, it will automatically scale to the width of the lineEdit when the image is embedded)

//实现缩放

// 创建QAction并设置图标
QAction *action2 = new QAction(this);
action->setIcon(QIcon(":/QQ_Image_touming/email.png"));

// 获取QPixmap对象，并进行缩放操作（这里将图像增大为50x50）
QPixmap pixmap3 = action->icon().pixmap(QSize(80, 80)).scaled(QSize(50, 50), Qt::KeepAspectRatio, Qt::SmoothTransformation);

// 将缩放后的图像重新设置为QIcon
action->setIcon(QIcon(pixmap3));

// 将QAction添加到QLineEdit控件的左侧位置
 ui->lineEdit->addAction(action, QLineEdit::LeadingPosition);