更改QTreeView的行背景颜色不起作用 [英] Changing the row background color of a QTreeView does not work

问题描述

我有一个 QTreeView ，并希望行的不同背景颜色，具体取决于它们的内容。为了实现这一点，我从 QTreeView 中导出一个类MyTreeView ，并实现了paint方法如下：

  void MyTreeView :: drawRow（QPainter * painter，
 const QStyleOptionViewItem& option，
 const QModelIndex& index）const 
 {
 QStyleOptionViewItem newOption（option）; 
 
 if（someCondition）
 {
 newOption.palette.setColor（QPalette :: Base，QColor（255，0，0））; 
 newOption.palette.setColor（QPalette :: AlternateBase，QColor（200，0，0））; 
} 
 else 
 {
 newOption.palette.setColor（QPalette :: Base，QColor（0，0，255））; 
 newOption.palette.setColor（QPalette :: AlternateBase，QColor（0，0，200））; 
} 
 
 QTreeView :: drawRow（painter，newOption，index）; 
} 
  

最初，我设置 setAlternatingRowColors / c>



我的问题：设置 QPalette :: Base的颜色没有效果

/ strong>。

但是，设置 QPalette :: AlternateBase会按预期工作。
我尝试了 setAutoFillBackground（true）和 setAutoFillBackground（false） b
$ b

有没有提示如何解决这个问题？

通过调整 MyModel设置颜色。 :: data（const QModelIndex& int role）为 Qt :: BackgroundRole 不提供所需的结果。在这种情况下，背景颜色仅用于行的一部分。

Qt版本： 4.7.3

---

更新：
由于未知原因 QPalette :: Base 似乎是不透明的。
setBrush不会改变。
我发现了以下解决方法：

  if（someCondition）
 {
 painter- ; fillRect（option.rect，Qt :: red）; 
 newOption.palette.setBrush（QPalette :: AlternateBase，Qt :: green）; 
} 
 else 
 {
 painter-> fillRect（option.rect，Qt :: orange）; 
 newOption.palette.setBrush（QPalette :: AlternateBase，Qt：blue）; 
} 
  

解决方案

扩展/折叠控件没有背景像行的休息，然后在 :: data（）中使用 Qt :: BackgroundRole $ c>（如 pnezis 在他们的答案），并将其添加到您的树视图类：

  void MyTreeView :: drawBranches（QPainter * painter，
 const QRect& rect，
 const QModelIndex& index）const 
 {
 if（某些条件取决于索引）
 painter-> fillRect（rect，Qt :: red）; 
 else 
 painter-> fillRect（rect，Qt :: green）; 
 
 QTreeView :: drawBranches（painter，rect，index）; 
} 
  



我使用Qt 4.8在Windows（Vista和7） 0和展开/折叠箭头具有适当的背景。问题是这些箭头是视图的一部分，因此不能在模型中处理。

I have a QTreeView and want different background colors for rows, depending on their content. To achieve this, I derived a class MyTreeView from QTreeView and implemented the paint method as follows:

    void MyTreeView::drawRow (QPainter* painter,
                              const QStyleOptionViewItem& option,
                              const QModelIndex& index) const
    {
      QStyleOptionViewItem newOption(option);

      if (someCondition)
      {
        newOption.palette.setColor( QPalette::Base, QColor(255, 0, 0) );
        newOption.palette.setColor( QPalette::AlternateBase, QColor(200, 0, 0) );
      }
      else
      {
        newOption.palette.setColor( QPalette::Base, QColor(0, 0, 255) );
        newOption.palette.setColor( QPalette::AlternateBase, QColor(0, 0, 200) );
      }

      QTreeView::drawRow(painter, newOption, index);
    }

Initially, I set setAlternatingRowColors(true); for the QTreeView.

My problem: Setting the color for QPalette::Base has no effect. Every second row remains white.

However, setting QPalette::AlternateBase works as expected. I tried setAutoFillBackground(true) and setAutoFillBackground(false) without any effect.

Are there any hints how to solve this problem? Thank you.

---

Remark: Setting the color by adapting MyModel::data(const QModelIndex&, int role) for Qt::BackgroundRole does not provide the desired result. In this case, the background color is used only for a part of the row. But I want to color the full row, including the left side with the tree navigation stuff.

Qt Version: 4.7.3

---

Update: For unknown reasons QPalette::Base seems to be opaque. setBrush does not change that. I found the following workaround:

    if (someCondition)
    {
        painter->fillRect(option.rect, Qt::red);
        newOption.palette.setBrush( QPalette::AlternateBase, Qt::green);
    }
    else
    {
        painter->fillRect(option.rect, Qt::orange);
        newOption.palette.setBrush( QPalette::AlternateBase, Qt:blue);
    }

解决方案

If the only problem is that the expanding/collapsing controls do not have a background like rest of the row then use Qt::BackgroundRole in ::data() of your model (as described by pnezis in their answer) and add this to your tree view class:

void MyTreeView::drawBranches(QPainter* painter,
                              const QRect& rect,
                              const QModelIndex& index) const
{
  if (some condition depending on index)
    painter->fillRect(rect, Qt::red);
  else
    painter->fillRect(rect, Qt::green);

  QTreeView::drawBranches(painter, rect, index);
}

I've tested this on Windows (Vista and 7) using Qt 4.8.0 and expanding/collapsing arrows have proper background. The problem is that those arrows are part of the view and thus cannot be handled in a model.

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