要求全黑底，再画一个长方形，再告诉我怎么改变长方形的颜色

qq664663358

自定义View
{
private Paint paint;
private RectF mRect;
public RectView(Context c){
super(c);
init();
}
public RectView(Context c,AttributeSet attr){
super(c,attr);
init();
}
public RectView(Context c,AttributeSet attr,int style){
super(c,attr,style);
init();
}
private void init(){
paint=new Paint();
paint.setColor(0xffffffff);//设置颜色
paint.setStrokeWidth(10);//设置宽度
paint.setStyle(Paint.Style.STROKE);//设置只画边框
mRect=new RectF(100,100,200,200);//左,上,右，下 的坐标
}
@Override
protected void onDraw(Canvas canvas)
{
//super.onDraw(canvas);
canvas.drawColor(0xff000000);//背景颜色
canvas.drawRect(mRect,paint);//绘制
}
}

谢了兄弟