自己研究吧。。。

//解释一下由于我们不是绘制到手机屏幕上所以通过Bitmap的形式来得到画布...
//一般情况下是绘制到手机屏幕上View 和SurfaceView 中的得到的Canvas
//添加图片到bitmaps
Bitmap bitmap = Bitmap.createBitmap(320, 480, Bitmap.Config.ARGB_8888);
Canvas bitCanvas = new Canvas(bitmap);
Paint paint=new Paint();
paint.setColor(Color.WHITE);
bitCanvas.drawText(ActivityContacts.mycontacts.get(0).getContactName(), 50, 50, paint);
File file = new File(getExternalCacheDir() + "/" + "drawBitmap" + ".jpg");
FileOutputStream fos=null;
try {
fos = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);

} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
try {
fos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}