销毁QHBoxLayout

Question

你好，这是我的代码，我在按钮事件处理程序中调用所有这些语句，如下所示

void analysis::on_pushButton_clicked()
{
 myplot * p = new myplot(gao.structpayloadgraph,gao1.structpayloadgraph, gao.structcol-2, "payload");

    myplot * p1 = new myplot(gao.structsessiongraph,gao.structsessiongraph ,gao.structcol-2, "session");


  QHBoxLayout * layout = new QHBoxLayout;
 ui->horizontalLayout_2->addLayout(layout);
 layout->addWidget(p);
 layout->addWidget(p1);

}

myplot是一个图形绘制类，但问题是，每次我点击按钮时，新的图形会出现，之前的图形会保留下来，就像一个!st click 2在第二次出现时就变成了4然后6......如何销毁按钮事件处理程序中的QHBoxLayout

谢谢

Answer 1

尝试只创建一个布局，并在每次单击后尝试执行类似于此布局->removeWidget(...)；的操作来删除prew图。

Answer 2

为on_pushButton_clicked()函数设置全局layout。

然后从其中删除所有以前的小部件：

    QLayoutItem *item;
    QLayoutIterator it = layout->iterator();

    while((item = it.takeCurrent()) != 0) {
        layout->remove(item->widget());
        delete item->widget();
    }

然后，您可以添加您的小部件：

    layout->addWidget(p);
    layout->addWidget(p1);

更新:仅适用于Qt3Support模式的。

UPD2:

    QLayoutItem *tItem;
    while (tItem = layout->takeAt(0) != 0)
        delete tItem;

Answer 3

你应该这样做：

在你的班上：

class analysis{

private:
      ...
      QHBoxLayout* hLayouot;
      ...

public:
      ...
 };


in the constructor you have to create the object:

hLayout = new QHBoxLayout(this);  --> if you can t put 'this' on constructor because your class doesn t hinerit from QWidget, you MUST delete hLayout inside the destructor!

while in your method void analysis::on_pushButton_clicked() you can call hLayout->removeWidget() ..
i have experienced problem too removing from layouts: so i called hLayout->clear() and then re-inserted the objects!