我无法使用 QFileDialog、C++ QT 保存 .txt 文件
I can't save .txt file with QFileDialog, C++ QT
这是我的代码:
void MainWindow::save(){
QString fileName = QFileDialog::getSaveFileName(this, tr("Save Text File"), path, tr("Text Files (*.txt)"));
if (fileName != "")
{
QFileInfo info(fileName);
path = info.absoluteDir().absolutePath();
QFile file(path);
if(!file.open(QIODevice::WriteOnly)){
QString text = ui->plainTextEdit->toPlainText();
QTextStream out(&file);
out << text ;
file.close();
}
}
}
但它在单击按钮后不会创建任何 .txt 文件:
connect(ui->saveButton, SIGNAL(clicked(bool)), this, SLOT(save()));
日志:
QIODevice::write (QFile, "C:\Users\kfg\Desktop"): device not open
感谢您的帮助:)
你犯了 2 个错误。
第一个在path = info.absoluteDir().absolutePath();
行中
这将为您提供目录的路径,而不是文件的路径。你应该使用 path = info.absoluteFilePath();
。参见 QFileInfo::absoluteFilePath()
。
接下来是当open
returns false
(失败)时写入"file"。
我认为你的代码是正确的,你应该使用这样的东西:
void MainWindow::save()
{
QString fileName = QFileDialog::getSaveFileName(this, tr("Save Text File"), path, tr("Text Files (*.txt)"));
if (fileName != "")
{
QFile file(QFileInfo(fileName).absoluteFilePath());
if (file.open(QIODevice::WriteOnly))
{
QString text = ui->plainTextEdit->toPlainText();
QTextStream out(&file);
out << text;
file.close();
}
else
{
//TODO: Error message
}
}
}
您可能还想检查文件是否已经存在并询问用户是否可以覆盖它...
void MainWindow::save()
{
QString fileName = QFileDialog::getSaveFileName(this, tr("Save Text File"), path, tr("Text Files (*.txt)"));
if (fileName != "")
{
QFile file(QFileInfo(fileName).absoluteFilePath());
if (file.exists())
{
QMessageBox::StandardButton chosenButton
= QMessageBox::warning(this, tr("File exists"), tr("The file already exists. Do you want to overwrite it?"),
QMessageBox::Ok | QMessageBox::Cancel,
QMessageBox::Cancel);
if (chosenButton != QMessageBox::Ok)
{
return; //Save was cancelled
}
}
if (!file.open(QIODevice::WriteOnly))
{
QMessageBox::critical(this, tr("Error"), tr("Failed to save file"));
return; //Aborted
}
//All ok - save data
QString text = ui->plainTextEdit->toPlainText();
QTextStream out(&file);
out << text;
file.close();
}
}
您还应该检查写入文件是否真的成功了。
这是我的代码:
void MainWindow::save(){
QString fileName = QFileDialog::getSaveFileName(this, tr("Save Text File"), path, tr("Text Files (*.txt)"));
if (fileName != "")
{
QFileInfo info(fileName);
path = info.absoluteDir().absolutePath();
QFile file(path);
if(!file.open(QIODevice::WriteOnly)){
QString text = ui->plainTextEdit->toPlainText();
QTextStream out(&file);
out << text ;
file.close();
}
}
}
但它在单击按钮后不会创建任何 .txt 文件:
connect(ui->saveButton, SIGNAL(clicked(bool)), this, SLOT(save()));
日志:
QIODevice::write (QFile, "C:\Users\kfg\Desktop"): device not open
感谢您的帮助:)
你犯了 2 个错误。
第一个在path = info.absoluteDir().absolutePath();
行中
这将为您提供目录的路径,而不是文件的路径。你应该使用 path = info.absoluteFilePath();
。参见 QFileInfo::absoluteFilePath()
。
接下来是当open
returns false
(失败)时写入"file"。
我认为你的代码是正确的,你应该使用这样的东西:
void MainWindow::save()
{
QString fileName = QFileDialog::getSaveFileName(this, tr("Save Text File"), path, tr("Text Files (*.txt)"));
if (fileName != "")
{
QFile file(QFileInfo(fileName).absoluteFilePath());
if (file.open(QIODevice::WriteOnly))
{
QString text = ui->plainTextEdit->toPlainText();
QTextStream out(&file);
out << text;
file.close();
}
else
{
//TODO: Error message
}
}
}
您可能还想检查文件是否已经存在并询问用户是否可以覆盖它...
void MainWindow::save()
{
QString fileName = QFileDialog::getSaveFileName(this, tr("Save Text File"), path, tr("Text Files (*.txt)"));
if (fileName != "")
{
QFile file(QFileInfo(fileName).absoluteFilePath());
if (file.exists())
{
QMessageBox::StandardButton chosenButton
= QMessageBox::warning(this, tr("File exists"), tr("The file already exists. Do you want to overwrite it?"),
QMessageBox::Ok | QMessageBox::Cancel,
QMessageBox::Cancel);
if (chosenButton != QMessageBox::Ok)
{
return; //Save was cancelled
}
}
if (!file.open(QIODevice::WriteOnly))
{
QMessageBox::critical(this, tr("Error"), tr("Failed to save file"));
return; //Aborted
}
//All ok - save data
QString text = ui->plainTextEdit->toPlainText();
QTextStream out(&file);
out << text;
file.close();
}
}
您还应该检查写入文件是否真的成功了。