实现图片缩放

private Bitmap resizeImage(Bitmap originalBitmap, int newWidth, int newHeight){
      int width = originalBitmap.getWidth();
      int height = originalBitmap.getHeight();
      //定义欲转换成的宽、高
//       int newWidth = 200;
//       int newHeight = 200;
      //计算宽、高缩放率
      float scanleWidth = (float)newWidth/width;
      float scanleHeight = (float)newHeight/height;
      //创建操作图片用的matrix对象 Matrix
      Matrix matrix = new Matrix();
      // 缩放图片动作
      matrix.postScale(scanleWidth,scanleHeight);   //两个参数为宽度和高度的缩放
      //旋转图片 动作
      //matrix.postRotate(45);
      // 创建新的图片Bitmap
      Bitmap resizedBitmap = Bitmap.createBitmap(originalBitmap,0,0,width,height,matrix,true);
      return resizedBitmap;
   }