Problem with QValidator and keyboard

[sonulohani]

use eventfilter instead.

[vhptt]

use eventfilter instead.

I dont know what you mean. Plz give me an example.

New problem:

QRegExp regExp("[A-Za-z0-9]+");
QRegExpValidator *regExpVal = new QRegExpValidator();
regExpVal->setRegExp (regExp);
ui->lineEditName->setValidator (regExpVal);
ui->lineEditAlias->setValidator (regExpVal);

QRegExp regExp("[A-Za-z0-9]+");
QRegExpValidator *regExpVal = new QRegExpValidator();
regExpVal->setRegExp (regExp);
ui->lineEditName->setValidator (regExpVal);
ui->lineEditAlias->setValidator (regExpVal);

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After do that, I cant type any alphanumeric character on lineEditName and lineEditAlias with Vietnamese keyboard. Qt always clear the character I've input.
How can I fix this ?