Android中EditText如何去除边框添加下划线

<span style="font-family: arial, helvetica, sans-serif;"><?xml version="1.0" encoding="utf-8"?> 
</span> 
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="fill_parent" 
android:layout_height="fill_parent" 
> 
<!--注意名称 --> 
<com.marine.study.lineedittext 
android:id="@+id/myedit" 
android:layout_width="fill_parent" 
android:layout_height="wrap_content" 
style="?android:attr/textviewstyle" 
android:background="@null" 
android:textcolor="@null" 
/> 
</linearlayout> 

public class lineedittext extends edittext { 
// 画笔 用来画下划线 
private paint paint; 
public lineedittext(context context, attributeset attrs) { 
super(context, attrs); 
paint = new paint(); 
paint.setstyle(paint.style.stroke); 
paint.setcolor(color.red); 
// 开启抗锯齿 较耗内存 
paint.setantialias(true); 
} 
@override 
protected void ondraw(canvas canvas) { 
super.ondraw(canvas); 
// 得到总行数 
int linecount = getlinecount(); 
// 得到每行的高度 
int lineheight = getlineheight(); 
// 根据行数循环画线 
for (int i = 0; i < linecount; i++) { 
int liney = (i + 1) * lineheight; 
canvas.drawline(0, liney, this.getwidth(), liney, paint); 
} 
} 
}