问Qt中一个奇怪的excel错误

EN

QAxObject *excel = NULL;
QAxObject *workbooks = NULL;
QAxObject *workbook = NULL;
excel = new QAxObject("Excel.Application");
excel->dynamicCall("SetVisible(bool)", false);
    // The code to set invisible, project will work correctly when set visible true
workbooks = excel->querySubObject("WorkBooks");
if(!workbooks){
    QMessageBox msgBox;
            msgBox.setWindowTitle("error information");
            msgBox.setText("workbooks error");
            msgBox.exec();
    return;
}
workbook = workbooks->querySubObject("Open(const QString&, QVariant)", file->filePath, 0);
    //This code will not execute correctly, causing "workbook error"
if(!workbook){
    QMessageBox msgBox;
            msgBox.setWindowTitle("error information");
            msgBox.setText("workbook error");
            msgBox.exec();
    return;
}

QAxObject * worksheet = workbook->querySubObject("WorkSheets(int)", 1);

QAxObject * usedrange = worksheet->querySubObject("UsedRange");
QAxObject * rows = usedrange->querySubObject("Rows");
QAxObject * columns = usedrange->querySubObject("Columns");

int intRowStart = usedrange->property("Row").toInt();
int intColStart = usedrange->property("Column").toInt();
int intCols = columns->property("Count").toInt();
int intRows = rows->property("Count").toInt();

workbook->dynamicCall("Close (Boolean)", false);
delete excel;