lineEdit(setText)和textEdit(setPlainText)设置初值失败导致程序崩溃

[JICJ]

我在下面窗口的lineEdit和textEdit进行初始化设置初值时，程序直接崩溃！
lineEdit的setText、textEdit的setPlainText都不行，目前不知道是什么原因导致的该问题

[ChrisW67]

I do not read or speak Chinese. This is what Google translate gives me:

When I initialize and set the initial value of lineEdit and textEdit in the window below, the program crashes directly!
LineEdit's setText and textEdit's setPlainText are not working. I don't know what caused the problem.

You will need to post your code and the stack back trace from your debugger.
Google translate:

您将需要从调试器发布您的代码和堆栈回溯。

[JICJ]

Here are some of my code and program crashes：

AddCreativeDlg::AddCreativeDlg(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::AddCreativeDlg)
{
    ui->setupUi(this);

    Qt::WindowFlags flags= this->windowFlags();
    setWindowFlags(flags&~Qt::WindowContextHelpButtonHint);

    m_str_title = "";
    m_str_des1 = "";
    m_str_des2 = "";
    m_str_def_visturl = "";
    m_str_def_showurl = "";
    m_str_mobile_visturl = "";
    m_str_mobile_showurl = "";

    m_str_def_visturl = "regDomainName";
    m_str_def_showurl = m_str_def_visturl;
    m_str_mobile_visturl = "mobileDomainName";
    m_str_mobile_showurl = m_str_mobile_visturl;

    ui->lineEdit_creativeTitle->setFixedWidth(300);
    ui->showUrl->setFixedWidth(300);
    ui->showUrl->setFixedHeight(30);
    ui->visitUrl->setFixedWidth(300);
    ui->visitUrl->setFixedHeight(30);
    ui->showMobUrl->setFixedWidth(300);
    ui->showMobUrl->setFixedHeight(30);
    ui->visitMobUrl->setFixedWidth(300);
    ui->visitMobUrl->setFixedHeight(30);

    ui->textEdit_creativeLine1->setFixedWidth(300);
    ui->textEdit_creativeLine1->setFixedHeight(50);
    ui->textEdit_creativeLine2->setFixedWidth(300);
    ui->textEdit_creativeLine2->setFixedHeight(50);

    /*textEdit or lineEdit have the same problem*/
    ui->visitUrl->setPlainText(m_str_def_visturl);                   //here is normal.
    ui->showUrl->setPlainText(m_str_def_visturl);         //here is crash.
    ui->visitMobUrl->setPlainText(m_str_mobile_visturl);
    ui->showMobUrl->setPlainText(m_str_mobile_showurl);


    InitMyEdit();        //This function is used to set initial values for several other lineedit or TextEdit.

}

[JICJ]

The following is my specific layout