搜索框实现

   QMargins margins = m_lineEditSearch->textMargins();
    m_lineEditSearch->setTextMargins(2, margins.top(), margins.right(), margins.bottom());
    m_lineEditSearch->setPlaceholderText(tr("搜索"));
    connect(m_lineEditSearch, SIGNAL(textChanged(QString)),this,SLOT(OnTextChanged(QString)),Qt::UniqueConnection);
    QHBoxLayout *pSearchLayout = new QHBoxLayout();
    pSearchLayout->addStretch();
    pSearchLayout->addWidget(m_labSearch);
    pSearchLayout->setSpacing(0);
    pSearchLayout->setContentsMargins(0, 0, 0, 0);
    m_lineEditSearch->setLayout(pSearchLayout);