TextArea也是一个多行文本编辑器。TextArea相比texttedit，增加了占位符文本，并添加了样式定义。 

import QtQuick
import QtQuick.Window
import QtQuick.Controls

Window {
    id: win
    width: 800
    height: 600
    visible: true

    TextArea {
        id: ta
        anchors.centerIn: parent
        placeholderText: qsTr("请在这里输入文本...")
        background: Rectangle {
            border.color: "red"
        }
    }
}

给TextArea加一个滚动条：

import QtQuick
import QtQuick.Window
import QtQuick.Controls

Window {
    id: win
    width: 800
    height: 600
    visible: true

    ScrollView {
        id: view
        width: 100
        height: 100
        TextArea {
            id: ta
            placeholderText: qsTr("请在这里输入文本...")
            background: Rectangle {
                border.color: "red"
            }
        }
    }
}