android开发步步为营之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;
        }
    }

android开发步步为营之66:android图片选取

原文：http://blog.csdn.net/figo0423/article/details/46883015