将项目添加到根目录时，QTreeview 无法正确更新 [英] QTreeview does not update correctly when items are added to the root

问题描述

我有一个树视图，它应该显示自己的数据集合的内容来实现这一点，我为树视图实现了一个新模型.当我将一个对象添加到任何父项时，一切正常并且新项显示在视图中，但是当我尝试向根项添加一个项时，该项不会显示，直到我将一个对象添加到另一个父项或我重置模型.

I've got a treeview, which should show the content of an own datacollection to achieve this, I've implemented a new model for the treeview. When I add an object to any parent Item everything works fine and the new Item is shown in the view, but when I try to add an item to the rootitem, this item does not show up until I add an Object to another parentitem or I reset the model.

我向模型添加行的方法如下所示:

My method to add rows to the model looks like this:

bool TreeModel::insertRows(int row, int count, const QModelIndex &parent, DataObject *object, QString name, QString path)
{
  if (!parent.isValid())
     return false;

  DataCollection* dataCollection = static_cast<DataCollection*>(parent.internalPointer());

  beginInsertRows(parent, dataCollection->Size(), dataCollection->Size());
  dataCollection->AddData(object, name.toStdString(), path.toStdString());
  endInsertRows();


  return true;
}

如何在向根元素添加项目时实现视图的更新?

How can I achieve an update of the view when I am adding an item to the rootelement?

推荐答案

我找到了一个非常简单的方法来解决这个问题 - 你所要做的就是添加emit layoutChanged(); 到你的 insertRows() 函数.

I found a really easy way to solve this - all you have to do is add emit layoutChanged(); to your insertRows() function.

最初我发出 dataChanged() 但显然它只影响项目的数据，与分支相关的数据不是项目的一部分.

Initially I was emitting dataChanged() but apparently it only affects the data of the item, the branch-related data is not part of an item.

它不如正确使用 beginInsertRows() 和 endInsertRows() 有效，但如果您拥有的项目数量不多，此解决方案应该绰绰有余.

It's not as efficient as doing it properly with beginInsertRows() and endInsertRows() but if the amount of items you have is not massive this solution should be more than sufficient.

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