如何设置渐变到QML TreeView背景？

import QtQuick 2.0
import QtQuick.Controls 2.0

TreeView {
    width: 400
    height: 300
    
    // 设置TreeView的背景为渐变
    background: Rectangle {
        gradient: Gradient {
            GradientStop { position: 0.0; color: "lightblue" }
            GradientStop { position: 1.0; color: "lightgreen" }
        }
    }
    
    // 其他TreeView的内容和设置...
}