Android保存图片到本地相册

好久没有写东西了。备份下知识吧。免得忘记了 。

首先贴一段代码 －－  这个是先生成一个本地的路径，将图片保存到这个文件中，然后扫描下sd卡。让系统相册重新加载下 。缺点就是只能保存到DCIM的文

件夹下边，暂时不知道怎么获取系统相机的路径，网上找了下说了好几个方法。其中有一条就是去读取本地的图片，然后根据一定的规则识别出本地相册的路径

保存下，不过觉得性能不是很好。谁有更好的方法可以提供下。

 private class DownloadTask extends AsyncTask<String, Integer, String> {

        private Context context;
        private String filepath;
        public int fileLength = 0; 

        public DownloadTask(Context context) {
            this.context = context;

            File cacheDir = new File(ImageLoader.getExternalCacheDir(context).getAbsolutePath() );
            if(!cacheDir.exists()) {
            	cacheDir.mkdirs();
            }
//            filepath = ImageLoader.getExternalCacheDir(context).getAbsolutePath()  + File.separator + "caihongjiayuan.jpg";
            filepath = UIUtils.generateDownloadPhotoPath();
        }

        @SuppressWarnings("resource")
		@Override
        protected String doInBackground(String... sUrl) {
            PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
            PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, getClass()
                    .getName());
            wl.acquire();

            InputStream input = null;
            OutputStream output = null;
            HttpURLConnection connection = null;
            try {
                URL url = new URL(sUrl[0]);
                connection = (HttpURLConnection) url.openConnection();
                connection.setConnectTimeout(5000);
                connection.setReadTimeout(20000);
                connection.connect();

                // expect HTTP 200 OK, so we don't mistakenly save error report
                // instead of the file
                if (connection.getResponseCode() != HttpURLConnection.HTTP_OK)
                    return "Server returned HTTP " + connection.getResponseCode() + " "
                            + connection.getResponseMessage();
                fileLength = connection.getContentLength();
                input = connection.getInputStream();
                output = new FileOutputStream(filepath);
                byte data[] = new byte[4096];
                long total = 0;
                int count;
                while ((count = input.read(data)) != -1) {
                    // allow canceling with back button
                    if (isCancelled())
                        return null;
                    total += count;

                    if (fileLength > 0) // only if total length is known
                        publishProgress((int)total);
                    output.write(data, 0, count);
                }
            } catch (Exception e) {
                return null;
            } finally {
                try {
                    if (output != null)
                        output.close();
                    if (input != null)
                        input.close();
                } catch (IOException ignored) {
                }

                if (connection != null)
                    connection.disconnect();
                wl.release();
            }
            return filepath;
        }

        @Override
        protected void onProgressUpdate(Integer... values) {
            // TODO Auto-generated method stub
            super.onProgressUpdate(values);
            float progress = (float)values[0]/(float)fileLength;
            mProgressInfo.setText(getString(R.string.download_progress_info,StringUtils.getKBUnitString(values[0]),StringUtils.getKBUnitString(fileLength)));
            mProgressBar.setProgress((int)(progress * 100));
        }

        @Override
        protected void onPostExecute(String result) {
            // TODO Auto-generated method stub
            super.onPostExecute(result);
            mDownloadView.setVisibility(View.GONE);
            if (!TextUtils.isEmpty(result)) {
            	ImageUtils.scanFile(mCurrentActivity, filepath);
            	ToastUtils.showLongToast(mCurrentActivity, mCurrentActivity.getString(R.string.tips_img_save_path, filepath));
			}else {
				ToastUtils.showLongToast(mCurrentActivity, R.string.tips_download_photo_faile);
			}

//
//            Bitmap bitmap = BitmapFactory.decodeFile(filepath);
//            boolean flag = ImageUtils.insertImageToAllbum(bitmap, mCurrentActivity);
//            if (flag) {
////				ToastUtils.showLongToast(mCurrentActivity, R.string.tips_download_photo_success);
//			}else {
//				ToastUtils.showLongToast(mCurrentActivity, R.string.tips_download_photo_faile);
//			}
        }
    }

　　参考了下别的文章，找到下边一个方法能解决大部分机型适配的问题，且可以将照片保存到系统相机拍完照的目录下。供大家参考。

private class DownloadTask extends AsyncTask<String, Integer, Boolean> {

        private Context context;
        public int fileLength = 0;
        private Bitmap bmp; 

        public DownloadTask(Context context) {
            this.context = context;

            File cacheDir = new File(ImageLoader.getExternalCacheDir(context).getAbsolutePath() );
            if(!cacheDir.exists()) {
                cacheDir.mkdirs();
            }
        }

        @SuppressWarnings("resource")
        @Override
        protected Boolean doInBackground(String... sUrl) {
            PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
            PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, getClass()
                    .getName());
            wl.acquire();

            InputStream input = null;
            ByteArrayOutputStream output = null;
            HttpURLConnection connection = null;
            try {
                URL url = new URL(sUrl[0]);
                connection = (HttpURLConnection) url.openConnection();
                connection.setConnectTimeout(5000);
                connection.setReadTimeout(20000);
                connection.connect();

                // expect HTTP 200 OK, so we don't mistakenly save error report
                // instead of the file
                if (connection.getResponseCode() != HttpURLConnection.HTTP_OK)
                    return false;
                fileLength = connection.getContentLength();
                input = connection.getInputStream();
                output = new ByteArrayOutputStream();
                byte data[] = new byte[4096];
                long total = 0;
                int count;
                while ((count = input.read(data)) != -1) {
                    // allow canceling with back button
                    if (isCancelled())
                        return false;
                    total += count;

                    if (fileLength > 0) // only if total length is known
                        publishProgress((int)total);
                    output.write(data, 0, count);
                }
                bmp = BitmapFactory.decodeByteArray(output.toByteArray(),0 , output.toByteArray().length);
                return true;

            } catch (Exception e) {
                return false;
            } finally {
                try {
                    if (output != null)
                        output.close();
                    if (input != null)
                        input.close();
                } catch (IOException ignored) {
                }

                if (connection != null)
                    connection.disconnect();
                wl.release();
            }
        }

        @Override
        protected void onProgressUpdate(Integer... values) {
            // TODO Auto-generated method stub
            super.onProgressUpdate(values);
            float progress = (float)values[0]/(float)fileLength;
            mProgressInfo.setText(getString(R.string.download_progress_info,StringUtils.getKBUnitString(values[0]),StringUtils.getKBUnitString(fileLength)));
            mProgressBar.setProgress((int)(progress * 100));
        }

        @Override
        protected void onPostExecute(Boolean result) {
            // TODO Auto-generated method stub
            super.onPostExecute(result);
            mDownloadView.setVisibility(View.GONE);
            if (result.booleanValue() && ImageUtils.insertImageToAllbum(bmp, mCurrentActivity)) {

            }else {
                ToastUtils.showLongToast(mCurrentActivity, R.string.tips_download_photo_faile);
            }

        }
    }

两个方法的区别就是将FileOutputStream换成了ByteArrayOutputStream项目中主要是有显示下载进度条的需求，所以稍微复杂了点。

另外： ImageUtils 中insertImage 方法如下。

public static boolean insertImageToAllbum(Bitmap bitmap,Context mContext) {
		if (bitmap != null) {
			String uri = MediaStore.Images.Media.insertImage(mContext.getContentResolver(),bitmap, "", "");
			if (!TextUtils.isEmpty(uri)) {
				String filePath = getRealPathFromURI(Uri.parse(uri),mContext);
				ToastUtils.showLongToast(mContext, mContext.getString(R.string.tips_img_save_path, filePath));
				scanFile(mContext,filePath);
				return true;
			}
		}
		return false;
	}

	public static void scanFile(Context mContext,String path){
		MediaScannerConnection.scanFile(mContext, new String[] { path }, null,
				new MediaScannerConnection.OnScanCompletedListener() {
					public void onScanCompleted(String path, Uri uri) {

					}
				});
	}

　　方法scanFile是让系统重新加载SD卡的 。。

　　over，有疑问请留言，欢迎指正错误。