我该如何在Qt中逐行读取文本文件?
我正在寻找与以下代码等效的Qt代码:
std::ifstream infile;
std::string line;
while (std::getline(infile, line))
{
...
}
使用以下代码:
QFile inputFile(fileName);
if (inputFile.open(QIODevice::ReadOnly))
{
QTextStream in(&inputFile);
while (!in.atEnd())
{
QString line = in.readLine();
...
}
inputFile.close();
}
QFile inputFile(QString("/path/to/file"));
inputFile.open(QIODevice::ReadOnly);
if (!inputFile.isOpen())
return;
QTextStream stream(&inputFile);
for (QString line = stream.readLine();
!line.isNull();
line = stream.readLine()) {
/* process information */
};
(!line.isNull())
是我所需要的。 - Harvey自从Qt 5.5版本,您可以使用 QTextStream::readLineInto
。它的行为类似于 std::getline
,并且可能比QTextStream :: readLine
更快,因为它可以重用字符串:
QIODevice* device;
QTextStream in(&device);
QString line;
while (in.readLineInto(&line)) {
// ...
}
或者像这样,从文件中读取:
包含的库:
#include "QFile"
#include "QDir"
代码:
QFile file;
file.setFileName("text.txt");
QDir::setCurrent("C:/Users/USER_NAME/Documents/QTCreatorWorkspace/untitled1");
QTextStream data(&file);
if(file.open(QIODevice::ReadOnly)){
ui->plainTextEdit->insertPlainText(file.readAll());
file.close();
}
else{
//Error statement
}
而对于将内容写入文件:
代码如下:QFile file;
file.setFileName("text.txt");
QDir::setCurrent("C:/Users/USER_NAME/Documents/QTCreatorWorkspace/untitled1");
QTextStream data(&file);
if(file.open(QIODevice::ReadWrite)){
data << ui->plainTextEdit->toPlainText();
file.close();
}
QFile file("file.txt");
if(!file.open(QIODevice::ReadOnly | QIODevice::Text))
return;
QTextStream in(&file);
QString line[3] = in.readLine();
for(int i=0; i<3; i++)
{
ui->textEdit->append(line[i]);
}
(QIODevice::ReadOnly | QIODevice::Text)
吗? - Alexander Malakhov