DockLayout布局
DockLayout布局要求子元素停靠式的布局。子元素可以通过horizontalAlignment: HorizontalAlignment.Center和verticalAlignment: VerticalAlignment.Top 确定自己在容器的哪个边。
DockLayout布局可以使用padding概念，确保子元素离容器的填充边距。
DockLayout例子
Container {
layout: DockLayout {}
Button {
text: "Button1"
horizontalAlignment: HorizontalAlignment.Right
verticalAlignment: VerticalAlignment.Top
}
Button {
text: "Button2"
horizontalAlignment: HorizontalAlignment.Right
verticalAlignment: VerticalAlignment.Center
}
}
如果第一个元素放到左上角，第二个元素也放在了左上角，无论是先声明横horizontalAlignment还是先声明竖verticalAlignment，最终结果都是后者遮盖住前者。
后者遮盖前者的例子：
import bb.cascades 1.0
Page {
Container {
layout: DockLayout {
}
Button {
text: "Button1"
horizontalAlignment: HorizontalAlignment.Right
verticalAlignment: VerticalAlignment.Top
}
Button {
text: "Button2"
horizontalAlignment: HorizontalAlignment.Right
verticalAlignment: VerticalAlignment.Top
}
}
}
去掉了老版本容器内元素的布局属性：
Label {
layoutProperties: DockLayoutProperties {
horizontalAlignment: HorizontalAlignment.Left }
}
改为了新版本的对齐属性：
Label {
horizontalAlignment: HorizontalAlignment.Left
}