Android(安卓)显示大图片

主要的代码如下：

　　　　 BitmapFactory.Options options = new BitmapFactory.Options();        //图片解析配置        options.inJustDecodeBounds = true;        //获取图片的属性并赋予options        BitmapFactory.decodeResource(getResources(), R.drawable.f1, options);        //获得图片实际宽高        int imgWidth = options.outWidth;        int imgHeight = options.outHeight;        System.out.println("outWidth = " + imgWidth);        System.out.println("outHeight = " + imgHeight);        //获取屏幕大小        WindowManager windowManager = (WindowManager) getSystemService(Context.WINDOW_SERVICE);        int windowwidth = windowManager.getDefaultDisplay().getWidth();        int windowheight = windowManager.getDefaultDisplay().getHeight();        System.out.println("width = " + windowwidth);        System.out.println("height = " + windowheight);        //计算缩放        int scale = 1;        int scaleX = imgWidth/windowwidth;        int scaleY = imgHeight/windowheight;        if(scaleX>1 && scaleX>scaleY) {            scale = scaleX;        }        if(scaleY>1 && scaleY>scaleX) {            scale = scaleY;        }        System.out.println("scale = " + scale);        //真的解析图片        options.inJustDecodeBounds = false;        options.inSampleSize = scale;        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.f1, options);        imageView.setImageBitmap(bitmap);

附（计算inSampleSize的工具方法）：

   public static int calculateInSampleSize(BitmapFactory.Options options,                                             int reqWidth, int reqHeight) {        final int height = options.outHeight;        final int width = options.outWidth;        int inSampleSize = 1;        if (height > reqHeight || width > reqWidth) {            final int heightRatio = Math.round((float) height                    / (float) reqHeight);            final int widthRatio = Math.round((float) width / (float) reqWidth);            inSampleSize = heightRatio < widthRatio ? widthRatio : heightRatio;        }        return inSampleSize;    }

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