QHBoxLayout析构引发的异常

自定义QHBoxLayout的布局，在析构时引发异常

Label       = new QLabel(QString("AAAAA"));
    ComboBox    = new QComboBox;
    SpacerItem  = new QSpacerItem(200, 20, QSizePolicy::Fixed);
    HBox_Layout = new QHBoxLayout;
    HBox_Layout->addWidget(Label,0);
    HBox_Layout->addWidget(ComboBox,1);
    HBox_Layout->addSpacerItem(SpacerItem);

    delete HBox_Layout;
    delete Label;
    delete ComboBox;
    delete SpacerItem;//异常发生异常在这里

查找QHBoxLayout源码发现

/*!
    Destroys this box layout.

    The layout's widgets aren't destroyed.
*/
QHBoxLayout::~QHBoxLayout()
{
}

说明QHBoxLayout会自动析构QSpacerItem；

所以异常发生是因为析构冲突