shape draw in imageview

I am trying to follow

http://developer.android.com/guide/topics/graphics/2d-graphics.html

and draw a shape on top of the imageview

my class is

package com.bayer.glucofacts;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.drawable.ShapeDrawable;
import android.graphics.drawable.shapes.OvalShape;
import android.widget.ImageView;

public class CustomDrawableImageView extends ImageView {
 private ShapeDrawable mDrawable;

 public CustomDrawableImageView(Context context) {
  super(context);
  int x = 10;
  int y = 100;
  int width = 300;
  int height = 50;
  mDrawable = new ShapeDrawable(new OvalShape());
  mDrawable.getPaint().setColor(0xff74AC23);
  mDrawable.setBounds(x, y, x + width, y + height);
 }

 protected void onDraw(Canvas canvas) {
  mDrawable.draw(canvas);
 }
开发者_如何学Go}

and did xl like

<com.cmp.app.CustomDrawableImageView
  android:id="@+id/bg_image" android:src="@drawable/book"
  android:layout_width="wrap_content" android:layout_height="wrap_content" />

but this crashes my app when i doo setContnetLayout in onCreate of the activity

when i was doing only ImageView without extending it for canvas drawing, it was working fine.

whats the problem ?

basically i plan to draw an image and a few lines on top of the image. how to do this ?

---

to solve this problem you must change your constructor to

public CustomDrawableImageView (Context context, AttributeSet attrs) {
    super(context, attrs);
}

it will work