Qt Reference Documentation

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# Qt 3 Support Members for QSettings

The following class members are part of the Qt 3 support layer. They are provided to help you port old code to Qt 4. We advise against using them in new code.

- QSettings class reference

## Public Types

enum | System { Unix, Windows, Mac }

## Public Functions

QStringList | entryList ( const QString & key ) const
void | insertSearchPath ( System system, const QString & path )
bool | readBoolEntry ( const QString & key, bool defaultValue = false, bool * ok = 0 )
double | readDoubleEntry ( const QString & key, double defaultValue = 0, bool * ok = 0 )
QString | readEntry ( const QString & key, const QString & defaultValue = QString(), bool * ok = 0 )
QStringList | readListEntry ( const QString & key, bool * ok = 0 )
QStringList | readListEntry ( const QString & key, QChar separator, bool * ok = 0 )
int | readNumEntry ( const QString & key, int defaultValue = 0, bool * ok = 0 )
bool | removeEntry ( const QString & key )
void | removeSearchPath ( System system, const QString & path )
void | resetGroup ()
void | setPath ( const QString & organization, const QString & application, Scope scope = Global )
QStringList | subkeyList ( const QString & key ) const
bool | writeEntry ( const QString & key, bool value )
bool | writeEntry ( const QString & key, double value )
bool | writeEntry ( const QString & key, int value )
bool | writeEntry ( const QString & key, const char * value )
bool | writeEntry ( const QString & key, const QString & value )
bool | writeEntry ( const QString & key, const QStringList & value )
bool | writeEntry ( const QString & key, const QStringList & value, QChar separator )

- 8 public functions inherited from QObject

## Member Type Documentation

### enum QSettings::System

Constant | Value | Description
--- | --- | ---
`QSettings::Unix` | `0` | Unix systems (X11 and Embedded Linux)
`QSettings::Windows` | `1` | Microsoft Windows systems
`QSettings::Mac` | `2` | Mac OS X systems

See also insertSearchPath() and removeSearchPath().

## Member Function Documentation

### QStringList QSettings::entryList ( const QString & key ) const

Returns a list of all sub-keys of key.

Use childKeys() instead.

For example, if you have code like

     QSettings settings;
     QStringList keys = settings.entryList("cities");
     ...

you can rewrite it as

     QSettings settings;
     settings.beginGroup("cities");
     QStringList keys = settings.childKeys();
     ...
     settings.endGroup();

### void QSettings::insertSearchPath ( System system, const QString & path )

This function is implemented as a no-op. It is provided for source compatibility with Qt 3. The new QSettings class has no concept of "search path".

### bool QSettings::readBoolEntry ( const QString & key, bool defaultValue = false, bool * ok = 0 )

Returns the value for setting key converted to a `bool`. If the setting doesn't exist, returns defaultValue.

If ok is not 0, *ok is set to true if the key exists, otherwise *ok is set to false.

Use value() instead.

For example, if you have code like

     bool ok;
     bool grid = settings.readBoolEntry("showGrid", true, &ok);

you can rewrite it as

     bool ok = settings.contains("showGrid");
     bool grid = settings.value("showGrid", true).toBool();

### double QSettings::readDoubleEntry ( const QString & key, double defaultValue = 0, bool * ok = 0 )

Returns the value for setting key converted to a `double`. If the setting doesn't exist, returns defaultValue.

If ok is not 0, *ok is set to true if the key exists, otherwise *ok is set to false.

Use value() instead.

For example, if you have code like

     bool ok;
     double pi = settings.readDoubleEntry("pi", 3.141592, &ok);

you can rewrite it as

     bool ok = settings.contains("pi");
     double pi = settings.value("pi", 3.141592).toDouble();

### QString QSettings::readEntry ( const QString & key, const QString & defaultValue = QString(), bool * ok = 0 )

Returns the value for setting key converted to a QString. If the setting doesn't exist, returns defaultValue.

If ok is not 0, *ok is set to true if the key exists, otherwise *ok is set to false.

Use value() instead.

For example, if you have code like

     bool ok;
     QString str = settings.readEntry("userName", "administrator", &ok);

you can rewrite it as

     bool ok = settings.contains("userName");
     QString str = settings.value("userName", "administrator").toString();

### QStringList QSettings::readListEntry ( const QString & key, bool * ok = 0 )

Returns the value of setting key converted to a QStringList.

If ok is not 0, *ok is set to true if the key exists, otherwise *ok is set to false.

Use value() instead.

For example, if you have code like

     bool ok;
     QStringList list = settings.readListEntry("recentFiles", &ok);

you can rewrite it as

     bool ok = settings.contains("recentFiles");
     QStringList list = settings.value("recentFiles").toStringList();

### QStringList QSettings::readListEntry ( const QString & key, QChar separator, bool * ok = 0 )

Returns the value of setting key converted to a QStringList. separator is ignored.

If ok is not 0, *ok is set to true if the key exists, otherwise *ok is set to false.

Use value() instead.

For example, if you have code like

     bool ok;
     QStringList list = settings.readListEntry("recentFiles", ":", &ok);

you can rewrite it as

     bool ok = settings.contains("recentFiles");
     QStringList list = settings.value("recentFiles").toStringList();

### int QSettings::readNumEntry ( const QString & key, int defaultValue = 0, bool * ok = 0 )

Returns the value for setting key converted to an `int`. If the setting doesn't exist, returns defaultValue.

If ok is not 0, *ok is set to true if the key exists, otherwise *ok is set to false.

Use value() instead.

For example, if you have code like

     bool ok;
     int max = settings.readNumEntry("maxConnections", 30, &ok);

you can rewrite it as

     bool ok = settings.contains("maxConnections");
     int max = settings.value("maxConnections", 30).toInt();

### bool QSettings::removeEntry ( const QString & key )

Use remove() instead.

### void QSettings::removeSearchPath ( System system, const QString & path )

This function is implemented as a no-op. It is provided for source compatibility with Qt 3. The new QSettings class has no concept of "search path".

### void QSettings::resetGroup ()

Sets the current group to be the empty string.

Use endGroup() instead (possibly multiple times).

For example, if you have code like

     QSettings settings;
     settings.beginGroup("mainWindow");
     settings.beginGroup("leftPanel");
     ...
     settings.resetGroup();

you can rewrite it as

     QSettings settings;
     settings.beginGroup("mainWindow");
     settings.beginGroup("leftPanel");
     ...
     settings.endGroup();
     settings.endGroup();

### void QSettings::setPath ( const QString & organization, const QString & application, Scope scope = Global )

Specifies the organization, application, and scope to use by the QSettings object.

Use the appropriate constructor instead, with QSettings::UserScope instead of QSettings::User and QSettings::SystemScope instead of QSettings::Global.

For example, if you have code like

     QSettings settings;
     settings.setPath("twikimaster.com", "Kanooth", QSettings::Global);

you can rewrite it as

     QSettings settings(QSettings::SystemScope, "twikimaster.com", "Kanooth");

### QStringList QSettings::subkeyList ( const QString & key ) const

Returns a list of all sub-keys of key.

Use childGroups() instead.

For example, if you have code like

     QSettings settings;
     QStringList groups = settings.entryList("cities");
     ...

you can rewrite it as

     QSettings settings;
     settings.beginGroup("cities");
     QStringList groups = settings.childKeys();
     ...
     settings.endGroup();

### bool QSettings::writeEntry ( const QString & key, bool value )

Sets the value of setting key to value.

Use setValue() instead.

### bool QSettings::writeEntry ( const QString & key, double value )

This is an overloaded function.

### bool QSettings::writeEntry ( const QString & key, int value )

This is an overloaded function.

### bool QSettings::writeEntry ( const QString & key, const char * value )

This is an overloaded function.

### bool QSettings::writeEntry ( const QString & key, const QString & value )

This is an overloaded function.

### bool QSettings::writeEntry ( const QString & key, const QStringList & value )

This is an overloaded function.

### bool QSettings::writeEntry ( const QString & key, const QStringList & value, QChar separator )

This is an overloaded function.

Use setValue(key, value) instead. You don't need separator.