QLineEdit placeholder text not working in Qt 4.6.3

I am using Qt 4.6.3, and tried to set some placeholder text on a QLineEdit. But these methods didn't work:

• using Qt开发者_JAVA百科 designer (uic)
• through code ui->lineedit.setPlaceholderText("phtext")
• setProperty("placeholderText","phtext")

The error is that setPlaceholderText is not a member of the QLineEdit class.

Is this a bug and\or is there a way to fix it?

The placeholderText property was introduced in Qt 4.7 (see documentation), so it doesn't exist in Qt 4.6.

While the placeholderText property exists in Qt 4.6.3, it's only enabled for Maemo5 builds:

// ### Qt 4.7: remove this #if guard
#if (QT_VERSION >= 0x407000) || defined(Q_WS_MAEMO_5)
    Q_PROPERTY(QString placeholderText READ placeholderText WRITE setPlaceholderText)
#endif

It seems like you're somehow mixing Qt platforms.