QTreeView更改节点图标和大小

ui->treeView->setIndentation(50);

然后使用stylesheet

QTreeView::branch:has-children:open{image: url(:/png/close.png);}  
QTreeView::branch:has-children:closed{image: url(:/png/open.png);} 
QTreeView::item{height: 50px; color: red}