Qt可执行文件在发行文件夹中运行-程序文件（x86）中的运行时错误

Question

I seem to be getting a runtime error when trying to run my Qt application.

I am able to successfully build my application in release mode and it runs just fine sitting in the release folder. That's not where it's going to sit when users install it, however. I need it to run in C:/Program Files (x86)/ApplicationName/application.exe .

So I moved the application there. I recently added some SQLite functionality to the application. So I expected to get some sort of missing dll file error. I did. So I found the correct dll file ( Qt5Sql.dll ) and moved it into that directory. Now I'm getting a Runtime Error.

To figure out what was causing this Runtime Error, I threw in a bunch of QMessageBox::warning s to see when it was getting the error. The error is being caused by this line of code:

sqlite = new SQLite(QString("%1%2").arg(myDocuments).arg(SQLite::DATABASE_NAME));

I checked to make sure I was getting the expected QString from QString("%1%2").arg(myDocuments).arg(SQLite::DATABASE_NAME) and I was.

Here is what that constructor looks like in sqlite.cpp :

SQLite::SQLite(const QString& path)
{
    database = QSqlDatabase::addDatabase("QSQLITE");
    database.setDatabaseName(path);

    if (!database.open())
    {
        QMessageBox::warning(NULL, "Error", "Failed to open database.");
    }
}

The peculiar thing is I know I'm not even getting into that constructor because I put a QMessageBox::warning before the first line in the constructor and I'm not seeing that before the Runtime Error. I am seeing the QMessageBox::warning directly before the constructor though.

Anyone out there have any idea what might be causing this?

Edit:

I believe I was missing the sqldriver folder which included the qsqlite.dll . I added that folder to where my exe file is, but I'm still getting a runtime error. I added the following to my code for debugging purposes:

QStringList drivers = QSqlDatabase::drivers();
QString ds;
int len = drivers.length();
for (int x = 0; x < len; x++)
{
    ds.append(QString("%1\n").arg(drivers[x]));
}
QMessageBox::warning(this, "DRIVERS", ds);
sqlite = new SQLite(QString("%1%2").arg(myDocuments).arg(SQLite::DATABASE_NAME));

The QMessageBox shows:

QSQLITE
QODBC
QODBC3
QPSQL
QPSQL7

After I click OK on the dialog, however, I am still getting the runtime error. Despite the QSQLITE driver clearly being available, I'm getting the runtime error on this line of code:

QSqlDatabase database = QSqlDatabase::addDatabase("QSQLITE");

Answer 1

为了简化您的生活，如果您使用的是Qt 5的最新版本，则可以在应用程序上使用windeployqt将依赖项拉到正确的位置。

Answer 2

After much hair pulling I figured out the issue. It seems one of the Qt5* dlls I was using was outdated. I saw this error when I moved the dll files from C:/Program Files... to my release folder and tried running a release version from QtCreator :

Cannot mix incompatible Qt library (version 0x50100) with this library (version 0x50101)

After seeing this, I updated all the Qt5* dll files in my C:/Program Files (x86)/ApplicationName/ directory and that fixed the problem.