qt中关于如何读取配置文件学习 （vs2008+qt+mysql项目）

（一）简单了解

配置文件（.ini)格式：

number=2

[config]

node1=sucess;iii

size=20

[source]

name=PC

其中每行必须顶格写，；后的为注释部分，可用［］来定义上一层的项目。

代码示例如下：

QSettings settings("/srv/c.ini",QSettings::IniFormat);

ui->label->setText(settings.value("config/node1").toString());

ui->lineEdit->setText(settings.value("config/size").toString());

int a=settings.value("number").toInt();

qDebug("the value a is: %d",a);

（二）深入一些

QT4.0一个非常有用的类QSettings

QSettings是qt4.0提供的一个读取配置文件的类，在windows平台，它提供了ini文件读些，注册表读写的功能。而且使用也非常简单。

QSettings::Format有两种:

QSettings::NativeFormat在windows平台可以读写windows注册表.

QSettings::IniFormat可以读写ini格式的配置文件

在Unix/X11平台下这两个Format效果是一样的。

1.读写注册表

//注意的就是路径名必须是"/"而不是"\\"等.否则不能读写,同时注意
//Format为QSettings::NativeFormat
QSettings *settings = new QSettings("HKEY_CURRENT_USER/", QSettings::NativeFormat);
//写HKEY_CURRENT_USER/regedit/test,设置test值为red
settings->setValue("regedit/test", "red");
//读 HKEY_CURRENT_USER/regedit/test,默认值是ddd
QString value = settings->value("regedit/test", "ddd").toString();
删除设置对应的是settings->remove( const QString & key )

2.读取ini配置文件

ini文件格式如下:

[Alpha]
Beta/Beta=1, 3, 4
Beta/Gamma=2
Beta/Delta=1111
Beta/Epsilon=5
Iota=7
Omicron=11
QSettings *settings = new QSettings(fileName, QSettings::IniFormat);
//写Beta/Beta
settings->setValue("Alpha/Beta/Beta", 68);

其他和读写注册表差不多,我就懒得写了，发觉QT4读写的这种配置,即可兼容windows下的ini文件,同时它的功能也比windows API所提供的功能强.

（三）综合理解

QSettings *ConfigIni = new QSettings(QSettings::Ini);

ConfigIni->insertSearchPath(QSettings::Unix, "/home/Dawei");.//配置文件目录

ConfigIni->writeEntry(QString::fromUtf8("/config./opt/参数1"), QString::fromUtf8("中文"));

String aaa = ConfigIni->readEntry(QString::fromUtf8("/config./opt/参数1");

delete ConfigIni;

会在/home/Dawei目录下生成config.rc配置文件内容为

[opt]

参数1=中文

---------------------------------------

QSettings settings("../etc/bpms.conf", QSettings::IniFormat, &app);

QString db_hostname = settings.value("hostname").toString();

QString db_database = settings.value("database").toString();

QString db_username = settings.value("username").toString();

QString db_password = settings.value("password").toString();

QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");

db.setHostName(db_hostname);

db.setDatabaseName(db_database);

db.setUserName(db_username);

db.setPassword(db_password);

---------------------------------------------------------------

需要#include <QSettings>

只举几个简单的例子：

1、用QSettings写注册表

QSettings *reg = new QSettings("HKEY_CURRENT_USER\\Software\\yinhaifan",
QSettings::NativeFormat);
reg->setValue("registered",true);
delete reg;

QSettings *reg = new QSettings("HKEY_CURRENT_USER\\Software\\yinhaifan", QSettings::NativeFormat); reg->setValue("registered",true); delete reg;

当然reg->setValue还可以写入字符串，整型之类的数据。

比如reg->setValue("registered","yes");

2、用QString读注册表

QSettings *reg = new QSettings("HKEY_CURRENT_USER\\Software\\yinhaifan",
QSettings::NativeFormat);
if (reg->value("registered",false).toBool())
{
QMessageBox::information(NULL,"information","registered");
}
delete reg;

QSettings *reg = new QSettings("HKEY_CURRENT_USER\\Software\\yinhaifan", QSettings::NativeFormat); if (reg->value("registered",false).toBool()) { QMessageBox::information(NULL,"information","registered"); } delete reg;

还可以toInt(),toString()等。

3、用QSettings写ini文件:

QSettings *ConfigIni = new QSettings("D:\\a.ini",QSettings::IniFormat,0);
ConfigIni->setValue("/config/node1",ui->lineEdit->text());
delete ConfigIni;

QSettings *ConfigIni = new QSettings("D:\\a.ini",QSettings::IniFormat,0); ConfigIni->setValue("/config/node1",ui->lineEdit->text()); delete ConfigIni;

4、用QSettings读ini文件:

QSettings *ConfigIni = new QSettings("D:\\a.ini",QSettings::IniFormat,0);
ui->lineEdit_2->setText(ConfigIni->value("/config/node1","20").toString());
delete ConfigIni;

QSettings *ConfigIni = new QSettings("D:\\a.ini",QSettings::IniFormat,0); ui->lineEdit_2->setText(ConfigIni->value("/config/node1","20").toString()); delete ConfigIni;

这几段代码都是在Qt Creator里面写的，所以用ui->lineEdit*->text()和ui->lineEdit*->setText()做输入和输出了。

在文档中的QSettings Class Reference部分讲的很清楚

---------------------------------------------------------------------

m_nDevNo = nDevNo;

QString strTemp;

QString xmlPath = CSC_APP.m_strWorkPath + "/InitInfo.ini";

QSettings *mySetting = new QSettings(xmlPath,QSettings::IniFormat);

foreach (QString group, mySetting->childGroups())

{

mySetting->beginGroup(group);

foreach (QString key, mySetting->childKeys())

{

QTextCodec *codec=QTextCodec::codecForName("GBK");

QString outStr = codec->toUnicode(key.toLatin1());

if (outStr == "自描述语言")

{

if ( mySetting->value(key,"0").toInt() == 1)

ui.SelfDspLgu->setCurrentIndex(1);

else

ui.SelfDspLgu->setCurrentIndex(0);

}

if (outStr == "工作语言")

{

if ( mySetting->value(key,"0").toInt() == 1)

ui.WorkLgu->setCurrentIndex(1);

else

ui.WorkLgu->setCurrentIndex(0);

}

if (outStr == "离线工作")

{

if ( mySetting->value(key,"0").toInt() == 1)

ui.WorkMode->setCurrentIndex(1);

else

ui.WorkMode->setCurrentIndex(0);

}

if (outStr == "召唤自描述方式")

{

if ( mySetting->value(key,"0").toInt() == 1)

ui.SelfDspSource->setCurrentIndex(1);

else

ui.SelfDspSource->setCurrentIndex(0);

}

if (outStr == "组播地址")

{

strTemp = mySetting->value(key,"236.8.8.8").toString();

ui.GrpAddress->setText(strTemp);

}

if (outStr == "接收端口号")

{

strTemp = mySetting->value("接收端口号","2000").toString();

ui.RecPort->setText(strTemp);

}

if (outStr == "发送端口号")

{

strTemp = mySetting->value("发送端口号","2001").toString();

ui.TargetPort->setText(strTemp);

}

if (outStr == "启用本机地址")

{

strTemp = mySetting->value(key,"0").toString();

}

if (outStr == "本机地址")

{

strTemp = mySetting->value(key,"0").toString();

ui.LocalIp->setText(strTemp);

}

if (outStr == "装置名称")

{

strTemp = mySetting->value(key,"0").toString();

ui.EqpName->setText(strTemp);

}

if (outStr == "装置地址")

{

strTemp = mySetting->value(key,"0").toString();

ui.EqpAddress->setText(strTemp);

}

if (outStr == "装置IP")

{

strTemp = mySetting->value(key,"0").toString();

ui.TargetIp->setText(strTemp);

}

}

mySetting->endGroup();