qregexpvalidator qlineedit email address

To validate an email address using QRegExpValidator in C++, you can follow these steps:

Step 1: Include the necessary header files Include the necessary header files for using QRegExpValidator and QLineEdit in your C++ code:

#include <QRegExpValidator>
#include <QLineEdit>

Step 2: Create a QLineEdit widget Create a QLineEdit widget to accept the user input for the email address:

QLineEdit *emailLineEdit = new QLineEdit(this);

Step 3: Create a QRegExpValidator Create a QRegExpValidator object to validate the email address using a regular expression pattern:

QRegExpValidator *emailValidator = new QRegExpValidator(this);

Step 4: Set the regular expression pattern Set the regular expression pattern for the email address validation:

QRegExp emailPattern("^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}$");
emailValidator->setRegExp(emailPattern);

Step 5: Set the validator for the QLineEdit widget Set the QRegExpValidator object as the validator for the QLineEdit widget:

emailLineEdit->setValidator(emailValidator);

Step 6: Use the QLineEdit widget Use the QLineEdit widget to get user input for the email address and validate it:

QString email = emailLineEdit->text();
if (emailValidator->validate(email, 0) == QValidator::Acceptable) {
    // Email address is valid
} else {
    // Email address is invalid
}

These steps will allow you to validate an email address using QRegExpValidator and QLineEdit in C++.