Android 解析二维码图片的两种方法介绍
AndroidAndroid 解析二维码图片的两种方法介绍解析二维码图片的两种方法介绍做了一个二维码扫描图片,主要是扫描不出来,看到一篇博客,其中的第二种方法可以扫描到,在此做笔记,以备后用,前面的进入相册,返回,到获取图片路径方法都一样;1.项目需求:知道项目需求,才知道先从哪里入手,见图一。(点击相册,打开图库)2.代码:1.打开图库代码:? 1 2 3 4 5 6mBtnOpenPicture.setOnClickListener(new View.OnClickListener() Override public void onClick(View v) /打开相册openGallery(); 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5);/*打开相册*/ private void openGallery() Intent picture = new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXT ERNAL_CONTENT_URI);startActivityForResult(picture, PICTURE);2.获取图片路径和解析。(1). 获取图片路径:getPath(uri);由于 Android 版本不同,返回的 uri 会有所不同,需要做特殊处理。移动电玩城 http:/www.44226.net? 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6SuppressLint(“NewApi“)private String getPath(Uri uri) int sdkVersion = Build.VERSION.SDK_INT;if (sdkVersion >= 19) /Log.e(“hxy“, “uri auth: “ + uri.getAuthority(); if (isExternalStorageDocument(uri) String docId = DocumentsContract.getDocumentId(uri);String split = docId.split(“:“);String type = split0;if (“primary“.equalsIgnoreCase(type) return Environment.getExternalStorageDirectory() + “/“ + split1; else if (isDownloadsDocument(uri) final String id = DocumentsContract.getDocumentId(uri);final Uri contentUri = ContentUris.withAppendedId(Uri.parse(“content:/downloads/public_down loads“), Long.valueOf(id);return getDataColumn(this, contentUri, null, null); else if (isMediaDocument(uri) final String docId = DocumentsContract.getDocumentId(uri);final String split = docId.split(“:“);final String type = split0;1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 3 0 3 1 3 2 3 3 3 4 3 5 3 6 3 7 3 8Uri contentUri = null;if (“image“.equals(type) contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI; else if (“video“.equals(type) contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI; else if (“audio“.equals(type) contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;final String selection = “_id=“;final String selectionArgs = new Stringsplit1;return getDataColumn(this, contentUri, selection, selectionArgs); else if (isMedia(uri) String proj = MediaStore.Images.Media.DATA;Cursor actualimagecursor = this.managedQuery(uri, proj, null, null, null);int actual_image_column_index = actualimagecursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA) ;actualimagecursor.moveToFirst();return actualimagecursor.getString(actual_image_column_index); else if (“content“.equalsIgnoreCase(uri.getScheme() if (isGooglePhotosUri(uri)return uri.getLastPathSegment(); return getDataColumn(this, uri, null, null);/ Fileelse if (“file“.equalsIgnoreCase(uri.getScheme() return uri.getPath();return null;public static String getDataColumn(Context context, Uri uri, String selection, String selectionArgs) Cursor cursor = null;final String column = “_data“;final String projection = column ;try cursor = context.getContentResolver().query(uri, projection,selection, selectionArgs, null); if (cursor != null return cursor.getString(column_index); finally if (cursor != null)cursor.close();return null;private static boolean isExternalStorageDocument(Uri uri) return “com.android.externalstorage.documents“.equals(uri.getAuthority();public static boolean isDownloadsDocument(Uri uri) return “com.android.providers.downloads.documents“.equals(uri.getAuthority() );public static boolean isMediaDocument(Uri uri) return “com.android.providers.media.documents“.equals(uri.getAuthority();public static boolean isMedia(Uri uri) return “media“.equals(uri.getAuthority();public static boolean isGooglePhotosUri(Uri uri) return “com.google.android.apps.photos.content“.equals(uri.getAuthority();6 1 6 2 6 3 6 4 6 5 6 6 6 7 6 8 6 9 7 0 7 1 7 2 7 3 7 4 7 5 7 6 7 7 7 8 7 9 8 0 8 1 8 25 8 6 8 7 8 8 8 9 9 0 9 1(2).开辟线程,解析图片,封装到 Result 中:我看了网上的 demo,大致上有 2 种方法。如下是第一种,稍后会把第二种方法也贴出来。? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27/* 解析二维码图片* param path* return*/protected Result scanningImage(String path) if (TextUtils.isEmpty(path) return null;Hashtable hints = new Hashtable();hints.put(DecodeHintType.CHARACTER_SET, “UTF-8“); / 设置二维码内容的 编码BitmapFactory.Options options = new BitmapFactory.Options();options.inJustDecodeBounds = true; / 先获取原大小scanBitmap = BitmapFactory.decodeFile(path,options);options.inJustDecodeBounds = false;int sampleSize = (int) (options.outHeight / (float) 200);if (sampleSize 注意:上面方法中有个关键的类,RGBLuminanceSource。 我把这个类的构造方法贴出来,因为我做的时候,发现网上 demo 这个类中构造传递的都是 Bitmap, 而我这个类却不是。分析传递的参数之后,我做了个转化:见如下,然后会发现报:NotFoundException. 这个异常是在 QRCodeReader 类:private static BitMatrix extractPureBits(BitMatrix image) throws NotFoundException 。(到这里我已经不是很懂了,然后又去网上搜索了下,最后自己探索出加 scanBitmap.getPixels(data, 0, scanBitmap.getWidth(), 0, 0, scanBitmap.getWidth(), scanBitmap.getHeight();),运行正常,能解析出来。? 1 2 3 4int data = new intscanBitmap.getWidth() * scanBitmap.getHeight(); /一定要加以下这个代码:/scanBitmap.getPixels(data, 0, scanBitmap.getWidth(), 0, 0, scanBitmap.getWidth(