Android 自定义View（3） -- 获得Bitmap的三种方法

1. 使用BitmapFactory解析图片

public void myUseBitmapFactory(Canvas canvas){
    //定义画笔
      Paint paint = new Paint();
    //获取资源流 
      Resources rec = getResources();
      InputStream in = rec.openRawResource(R.drawable.haha);
    //设置图片
       Bitmap bitmap = BitmapFactory.decodeStream(in);
    //绘制图片
      canvas.drawBitmap(bitmap,0,20,paint);
}

2. 使用BitmapDrawable解析图片

public void myUseBitmapDrawable(Canvas canvas){
    //定义画笔
      Paint paint = new Paint();
    //获得资源
      Resources rec = getResources();
      BitmapDrawable bitDrawable = (BitmapDrawable) rec.getDrawable(R.drawable.haha);
    //得到Bitmap
      Bitmap bitmap = bitmapDrawable.getBitmap();
    //在画板上绘制图片
      canvas.drawBitmap(bitmap,20,120,paint);
}

3. 使用InputStream和BitmapDrawable绘制

public void myUseInputStreamBitmapDrawable(Canvas canvas){
    //定义画笔
      Paint paint = new Paint();
    //获得资源
      Resources rec = getResources();
      InputStream in = rec.openRawResource(R.drawable.haha);
    //解析数据流
      BitmapDrawable bitDrawable = new BitmapDrawable(in);
    //得到Bitmap
      Bitmap bitmap = bitmapDrawable.getBitmap();
    //在画板上绘制图片
      canvas.drawBitmap(bitmap,100,100,paint);
}