qt 基础知识 GIS

（1）  qt 加载dll
QLibrarytestlib("H:\\UltraVNCProjectRoot\\UltraVNCProjectRoot\\UltraVNC\\winvnc\\Debug\\winvnc.dll");

if(testlib.load()){

typedefbool(*lpfun)(char*hostchar,char*IDchar);

lpfunp=(lpfun)testlib.resolve("test");

if(p==NULL)return;

charstrHost[]="10.21.140.39";chartestID[]="666";p(strHost,testID);return;

}
qstring 和LPCWSTR 转换

QString teststring= QDir::currentPath();
files=teststring.split("out",QString::KeepEmptyParts,Qt::CaseSensitive);
QString filepath=files[0].append("/ThirdPartyLib/RemoteTools.dll");

QString filepath=files[0].append("/ThirdPartyLib/VNC/RemoteTools.dll");

hmodule=LoadLibrary((LPCWSTR)filepath.utf16());

qt 隐藏button

 ui->pushButton->hide()；//隐藏的情况下，没按就保持隐藏

qt 给qpushbutton 设置样式表

用qt designer 打开ui form 选中button 然后属性表设置stylesheet ，复制进去就行了

QPushButton
{
font:bold 17px "微软雅黑";
color: #FFFFFF;
background-color: #46aef2;
border: 0px solid rgba(255,255,255,255);

}
QPushButton:hover{background-color:#ffb82f;}
QPushButton:disabled{background-color:#9c9c9c;color:#c2c2c2;}

 qt 获得某一代码目录下的 .CPP 和。h 的文件 的文件数目  qt里面的例子WordCount

  QStringList files = findFiles("http://www.cnblogs.com/", QStringList() << "*.cpp" << "*.h");

QStringList findFiles(const QString &startDir, QStringList filters)
{
    QStringList names;
    QDir dir(startDir);

    foreach (QString file, dir.entryList(filters, QDir::Files))
        names += startDir + "/" + file;

    foreach (QString subdir, dir.entryList(QDir::AllDirs | QDir::NoDotAndDotDot))
        names += findFiles(startDir + "/" + subdir, filters);
    return names;
}

 qDebug() << files.count() << "files";

qt获得某一文件下的文字数量

typedef QMap<QString, int> WordCount;

// countWords counts the words in a single file. This function is// called in parallel by several threads and must be thread// safe.
WordCount countWords(const QString &file)
{
    QFile f(file);
    f.open(QIODevice::ReadOnly);
    QTextStream textStream(&f);
    WordCount wordCount;

    while (textStream.atEnd() == false)
        foreach (QString word, textStream.readLine().split(" "))
            wordCount[word] += 1;

    return wordCount;
}

QString 转成char *

QString requestID;

char* ch;
QByteArray ba = requestID.toLatin1();

ch=ba.data();