QIODevice::ReadOnly

QIODevice::ReadOnly is a constant used in Qt framework to indicate that the device is open for reading only. This means that you cannot write data to the device using this mode. It is commonly used when reading data from a file or a network socket.

For example, you can open a file for reading using the following code:

QFile file("myFile.txt");
if (file.open(QIODevice::ReadOnly)) {
   // Read data from the file
}

In this example, the file is opened in read-only mode using the QFile class. Once the file is opened, you can read data from it using the appropriate methods.

It is important to note that opening a file in read-only mode does not allow you to modify the file. If you need to modify the file, you will need to open it in a different mode, such as QIODevice::WriteOnly.