递归地遍历目录中的所有文件及其Qt中的子目录

I want to recursively scan a directory and all its sub-directories for files with a given extension - for example, all *.jpg files. How can you do that in Qt?

我想递归地扫描一个目录和它的所有子目录，找到一个给定扩展名的文件——例如，所有的*.jpg文件。如何在Qt中做到这一点?

3 个解决方案

#1

I suggest you give a look at QDirIterator.

我建议你看看QDirIterator。

QDirIterator it(dir, QStringList() << "*.jpg", QDir::Files, QDirIterator::Subdirectories);
while (it.hasNext())
    qDebug() << it.next();

This makes the algorithm more scalable. QDir::entryList() might take suddenly large amount of memory when many files are stored in a single directory. Not good on small embedded devices.

这使得算法更具有可扩展性。当许多文件存储在一个目录中时，entryList()可能会突然占用大量内存。不适合小型嵌入式设备。

#2

This should work :

这应该工作:

void scanDir(QDir dir)
{
    dir.setNameFilters(QStringList("*.nut"));
    dir.setFilter(QDir::Files | QDir::NoDotAndDotDot | QDir::NoSymLinks);

    qDebug() << "Scanning: " << dir.path();

    QStringList fileList = dir.entryList();
    for (int i=0; i<fileList.count(); i++)
    {
        if(fileList[i] != "main.nut" &&
           fileList[i] != "info.nut")
        {
            qDebug() << "Found file: " << fileList[i];
        }
    }

    dir.setFilter(QDir::AllDirs | QDir::NoDotAndDotDot | QDir::NoSymLinks);
    QStringList dirList = dir.entryList();
    for (int i=0; i<dirList.size(); ++i)
    {
        QString newPath = QString("%1/%2").arg(dir.absolutePath()).arg(dirList.at(i));
        scanDir(QDir(newPath));
    }
}

The differences from your code are the following:

代码的不同之处如下:

Breadth first search instead of depth first search (no reason for it, I just prefer it)
广度优先搜索而不是深度优先搜索(没有理由，我只是喜欢它)
More filters in order to avoid sym links
更多的过滤器，以避免sym链接
EntryList instead of EntryInfoList. You don t need if you just want the name of the file.
EntryList代替EntryInfoList。如果只想要文件的名称，则不需要。

I tested it and it works correctly, but notice the following:

我对它进行了测试，结果是正确的，但是请注意以下内容:

This may take a lot of time, so consider running it from thread
这可能需要很多时间，所以考虑从线程中运行它
If there is deep recursion you may have problem with your stack
如果存在深度递归，您的堆栈可能有问题

#3

I used QDirIterator.

我用QDirIterator。

Here's how I do it and how simple it was to find all XML absolute file paths recursively very fast (Qt4.8.1):

下面是我的操作方法，简单地发现所有XML绝对文件路径递归非常快(Qt4.8.1):

// used to store the file paths
filesStack = new QStack<QString>();

// I use a file dialog to let the user choose the root folder to search in
if (fileDialog->exec() == QFileDialog::Accepted) {
    QDir selectedDir(fileDialog->selectedFiles().first());
    selectedDir.setFilter(QDir::Files |
                          QDir::Dirs | QDir::NoDot | QDir::NoDotDot);
    QStringList qsl; qsl.append("*.xml"); // I only want XML files
    selectedDir.setNameFilters(qsl);
    findFilesRecursively(selectedDir);
}

// this function stores the absolute paths of each file in a QVector
void findFilesRecursively(QDir rootDir) {
    QDirIterator it(rootDir, QDirIterator::Subdirectories);
    while(it.hasNext()) {
        filesStack->push(it.next());
    }
}

Thanks to everyone for the hints.

谢谢大家的提示。

EDIT: I may have omitted some declarations, beware.

编辑:我可能漏掉了一些声明，小心。

#1