android 開發中的一些實用方法/工具類

刪除圖片/文件夾並通知系統刷新圖庫資源

//刪除文件後更新媒體庫   filepath（文件夾路徑）務必儘量精確
    public static void updateFileFromDatabase(Context context,String filepath){
        String where=MediaStore.Audio.Media.DATA+" like \""+filepath+"%"+"\"";
         int i=  context.getContentResolver().delete(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,where,null);
         if(i>0){
             Log.e(TAG,"媒體庫更新成功！");
         }
    }

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拷貝圖片到指定文件夾返回絕對路徑/調整圖片方向

public class ImgUtils {
    //保存文件到指定路徑
    public static String saveImageToGallery(Context context, Bitmap bmp) {
        // 首先保存圖片
        String storePath = Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + "xczj";
        File appDir = new File(storePath);
        if (!appDir.exists()) {
            appDir.mkdir();
        }
        String fileName = System.currentTimeMillis() + ".jpg";
        File file = new File(appDir, fileName);
        try {
            FileOutputStream fos = new FileOutputStream(file);
            //通過io流的方式來壓縮保存圖片
            boolean isSuccess = bmp.compress(Bitmap.CompressFormat.JPEG, 60, fos);
            fos.flush();
            fos.close();

            //把文件插入到系統圖庫
            //MediaStore.Images.Media.insertImage(context.getContentResolver(), file.getAbsolutePath(), fileName, null);

            //保存圖片後發送廣播通知更新數據庫
            Uri uri = Uri.fromFile(file);
            context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, uri));
            if (isSuccess) {
                return file.getAbsolutePath();
            } else {
                return "false";
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "false";
    }



    /**
     * @author yukaida
     * @param absolutePath 照片的絕對路勁
     * @return 重新調整方向之後的bitmap圖片
     */
    public static Bitmap orientation(String absolutePath){
        Bitmap bitmap_or= BitmapFactory.decodeFile(absolutePath);
        try {

            ExifInterface exif = new ExifInterface(absolutePath);
            int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, 1);
            Log.d("EXIF", "Exif: " + orientation);
            Matrix matrix = new Matrix();
            if (orientation == 6) {
                matrix.postRotate(90);
            }
            else if (orientation == 3) {
                matrix.postRotate(180);
            }
            else if (orientation == 8) {
                matrix.postRotate(270);
            }
            bitmap_or= Bitmap.createBitmap(bitmap_or, 0, 0, bitmap_or.getWidth(), bitmap_or.getHeight(), matrix, true); // rotating bitmap
            return bitmap_or;
        }
        catch (Exception e) {
        }
        return null;
    }

}