QComboBox未正确呈现添加的项目

Question

我对QComboBox有奇怪的行为，基本上我监听currentIndexChanged信号，然后基于该索引从QStrList填充第二个QComboBox。我的问题是第二个QComboBox被正常填充，但没有正确显示文本，直到我点击项目，然后它出现，我用一个插槽来填充QComboBox。

InfoEmployer::InfoEmployer(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::InfoEmployer)
{
    ui->setupUi(this);
    ui->gradeCombo->addItem("");
    ui->gradeCombo->addItem("200");
    ui->gradeCombo->addItem("300");
    ui->gradeCombo->addItem("400");
    ui->gradeCombo->addItem("500");
    ui->gradeCombo->addItem("600");
    ui->gradeCombo->addItem("700");
    QStringList levels;
    levels << "10" << "20" << "30" << "40" << "50" << "60" << "70" << "80" << "90" << "100" << "110" << "120";
    m_levelsContainer[0] = levels;
    levels.clear();
    levels << "11" << "22" << "33" << "44" << "55" << "66" << "77" << "88" << "99" << "110" << "120" << "131";
    m_levelsContainer[1] = levels;
    levels.clear();
    levels << "12" << "24" << "36" << "48" << "60" << "72" << "84" << "96" << "108" << "120" << "132" << "144";
    m_levelsContainer[2] = levels;
    levels.clear();
    levels << "13" << "26" << "39" << "53" << "66" << "79" << "92" << "105" << "118" << "132" << "145" << "158";
    m_levelsContainer[3] = levels;
    levels.clear();
    levels << "14" << "29" << "43" << "58" << "72" << "86" << "101" << "115" << "130" << "144" << "158" << "173";
    m_levelsContainer[4] = levels;
    levels.clear();
    levels << "16" << "32" << "47" << "63" << "79" << "95" << "110" << "126" << "142" << "158" << "173" << "189";
    m_levelsContainer[5] = levels;
    levels.clear();
    connect(ui->gradeCombo, SIGNAL(currentIndexChanged(int)), this, SLOT(getGradeLevels(int)));
}
// The slot
    void InfoEmployer::getGradeLevels(int indx)
    {
        if(indx != 0)
        {
            ui->levelCombo->clear();
            QStringList levels = m_levelsContainer[indx - 1];
            for(int i = 0; i < levels.length(); ++i)
                ui->levelCombo->addItem(levels[i]);
        }
    }

请注意，只有当我以编程方式填充QComboBox时，才会出现此问题。

更新

我发现问题不在我的代码中，但在QComboBox上！在QComboBox上插入超过10个项目会使其无法正确显示项目，如果我插入少于或10个项目，则所有项目都会正确显示。我的Qt版本是5.0.2和MinGW 4.7，请测试并确认。

Answer 1

您可以尝试执行此

ui->levelCombo->setCurrentIndex(-1); // deselect items, i have some proplems without this line
ui->levelCombo->setCurrentIndex(0); // select first item in combobox

Answer 2

我的Qt似乎有一个错误，我把成绩降到了Qt 4.8.3，问题就解决了。