android Drawable 缩放

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Bitmap.Config;
import android.graphics.PorterDuff.Mode;
import android.graphics.drawable.Drawable;

public class FunctionUtil {

 /*********************图形缩放**************************/
 public static Bitmap imageScale(Bitmap bitmap, int dst_w, int dst_h){
  
  int  src_w = bitmap.getWidth();
  int  src_h = bitmap.getHeight();
  float scale_w = ((float)dst_w)/src_w;
  float  scale_h = ((float)dst_h)/src_h;
  Matrix  matrix = new Matrix();
  matrix.postScale(scale_w, scale_h);
  Bitmap dstbmp = Bitmap.createBitmap(bitmap, 0, 0, src_w, src_h, matrix, true);
  
  return dstbmp;
 }
 
 /*********************Drawable转Bitmap************************/
 public static Bitmap drawabletoBitmap(Drawable drawable){
  
  int width = drawable.getIntrinsicWidth();
  int height = drawable.getIntrinsicWidth();
  
  Bitmap bitmap = Bitmap.createBitmap(width, height, drawable.getOpacity() != PixelFormat.OPAQUE ?
     Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565);
  Canvas canvas = new Canvas(bitmap);
  drawable.setBounds(0, 0, width, height);
  
  drawable.draw(canvas);
  
  return bitmap;
 }
 
 /***************************图片圆角处理********************************/
 public static Bitmap getRCB(Bitmap bitmap, float roundPX) //RCB means Rounded Corner Bitmap
 {
  Bitmap dstbmp = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Config.ARGB_8888);
  Canvas canvas = new Canvas(dstbmp);
  
  final int color = 0xff424242;
  final Paint paint = new Paint();
  final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
  final RectF rectF = new RectF(rect);
  paint.setAntiAlias(true);
  canvas.drawARGB(0, 0, 0, 0);
  paint.setColor(color);
  canvas.drawRoundRect(rectF, roundPX, roundPX, paint);
  paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
  canvas.drawBitmap(bitmap, rect, rect, paint);

  return dstbmp;
 }
}