Bitmap.creatBirmap()的简单使用

1.代码

Bitmap b = BitmapFactory.decodeResource(getResources() , R.drawable.a);
        ImageView cbt = (ImageView) findViewById(R.id.btmp1);
        cbt.setImageBitmap(b);
        Log.i("mydate" , b.getWidth() + "    " + b.getHeight()); //

        ImageView cbtwdf = (ImageView) findViewById(R.id.btmp2);
        //对图片进行裁剪
        Bitmap bwdf = Bitmap.createBitmap(b , b.getWidth()/2 , b.getHeight()/2 , b.getWidth()/2 , b.getHeight()/2);
        cbtwdf.setImageBitmap(bwdf);
        Log.i("mydate" , bwdf.getWidth() + "    " + bwdf.getHeight()); //

        //如果想要对裁剪后的图片进行缩放
        Matrix matrix = new Matrix();
        float wscale = (b.getWidth() / (b.getWidth()/2)) ; //如果裁剪后的图片要放大则乘以这个比值
        float hscale = (b.getHeight() / (b.getHeight()/2)) ;
        matrix.postScale(wscale , hscale);
        Bitmap bscale = Bitmap.createBitmap(b , b.getWidth()/2 , b.getHeight()/2 , b.getWidth()/2 , b.getHeight()/2 , matrix , true);
        ImageView cbtscale = (ImageView) findViewById(R.id.btmp3);
        cbtscale.setImageBitmap(bscale);
        Log.i("mydate" , bscale.getWidth() + "    " + bscale.getHeight()); //

2.显示:

3.打印如下：

mydate: 1536    1536
mydate: 768    768
mydate: 1536    1536