android开发稳扎稳打之66:android图片选取

         最近做一个页面，反馈问题页面，有个用户上传问题图片的功能。本来很笨的想把系统的所有图片列出来，然后让用户选择，后来发现原来可以直接打开手机所有图片的api的。效果如图：

          给出主要代码：

          1、选择图片

    Intent i = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);    startActivityForResult(i, 1);

          2、获取图片

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {        super.onActivityResult(requestCode, resultCode, data);        try {            if (requestCode == 1 && resultCode == RESULT_OK && null != data) {                Uri selectedImage = data.getData();                String[] filePathColumn = { MediaStore.Images.Media.DATA };                Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);                cursor.moveToFirst();                int columnIndex = cursor.getColumnIndex(filePathColumn[0]);                String picturePath = cursor.getString(columnIndex);                cursor.close();                BitmapFactory.Options opts = new BitmapFactory.Options();                opts.inJustDecodeBounds = true;                BitmapFactory.decodeFile(picturePath, opts);                opts.inSampleSize = computeSampleSize(opts, -1, 160 * 160);//转换成160*160大小图片                // 这里一定要将其设置回false，因为之前我们将其设置成了true                opts.inJustDecodeBounds = false;                try {                    Bitmap bmp = BitmapFactory.decodeFile(picturePath, opts);                    if (mPosition != 0)// 替换                    {                        fba.getmImgs().set(mPosition, bmp);                        fba.getmImgPaths().set(mPosition, picturePath);                    } else {                        fba.getmImgs().add(bmp);                        fba.getmImgPaths().add(picturePath);                    }                } catch (OutOfMemoryError err) {                    if (err != null) {                        err.printStackTrace();                    }                }                fba.notifyDataSetChanged();            }        } catch (Exception e) {            if (e != null) {                e.printStackTrace();            }        } catch (OutOfMemoryError e) {            if (e != null) {                e.printStackTrace();            }        }    }

   public int computeSampleSize(BitmapFactory.Options options, int minSideLength, int maxNumOfPixels) {        int initialSize = computeInitialSampleSize(options, minSideLength, maxNumOfPixels);        int roundedSize;        if (initialSize <= 8) {            roundedSize = 1;            while (roundedSize < initialSize) {                roundedSize <<= 1;            }        } else {            roundedSize = (initialSize + 7) / 8 * 8;        }        return roundedSize;    }    private int computeInitialSampleSize(BitmapFactory.Options options, int minSideLength, int maxNumOfPixels) {        double w = options.outWidth;        double h = options.outHeight;        int lowerBound = (maxNumOfPixels == -1) ? 1 : (int) Math.ceil(Math.sqrt(w * h / maxNumOfPixels));        int upperBound = (minSideLength == -1) ? 128 : (int) Math.min(Math.floor(w / minSideLength), Math.floor(h / minSideLength));        if (upperBound < lowerBound) {            return lowerBound;        }        if ((maxNumOfPixels == -1) && (minSideLength == -1)) {            return 1;        } else if (minSideLength == -1) {            return lowerBound;        } else {            return upperBound;        }    }