Qt quick中,控件阴影效果

import QtQuick 2.0
import QtQuick.Controls 1.4
import QtQuick.Controls.Styles 1.4
import QtGraphicalEffects 1.0
//使用背景色的按钮
Item {

width: 320;
height: 480;
Button{
id:btn;
height: 40;
width:100;
anchors.left: parent.left
text:"按钮";
style:component_btnstyle;//注意 用Component封装了！否则错误
layer.enabled: true
layer.effect: DropShadow {
transparentBorder: true//绘制边框阴影
color: "#80000000";
radius: 15.0;
id:drop;

//cached: true;
horizontalOffset: 0;
verticalOffset: 0;
samples: 16;
smooth: true;
}

}

Component {
id: component_btnstyle
ButtonStyle{
id:btnstyle;

background:Rectangle{
id:rect;
width: control.windth
height: control.height;
color:setcolor(control)
radius:2;
border.color: "#ccc"
antialiasing: true
Rectangle {
//再嵌套一层矩形 可用作内边框 颜色透。比用border灵活
anchors.fill: parent
anchors.margins: 1
color: "transparent"
antialiasing: true
visible: !control.pressed  //点击的时候隐藏
border.color: "#aaffffff"
radius: height/2

}

}
}
}

function setcolor(mcontrol)
{
if(mcontrol.pressed===true)
{
return "#ccc";
}

return "white"

}

}