ZXing是Google的一個開源函式庫,可以用來產生二維碼、掃描二維碼。本文所介紹的是第一部分。
首先上效果圖:
ZXing相關各種文件官方下載地址:https://github.com/zxing/zxing/releases
或者在這裡下載(只有本項目版本所用的jar包,jar包,編號:3.2.0):連結:http://pan.baidu.com/s/1pLqAR5x
1.產生二維碼的工具類
/** * 二维码生成工具类 */ public class QRCodeUtil { /** * 生成二维码Bitmap * * @param content 内容 * @param widthPix 图片宽度 * @param heightPix 图片高度 * @param logoBm 二维码中心的Logo图标(可以为null) * @param filePath 用于存储二维码图片的文件路径 * @return 生成二维码及保存文件是否成功 */ public static boolean createQRImage(String content, int widthPix, int heightPix, Bitmap logoBm, String filePath) { try { if (content == null || "".equals(content)) { return false; } //配置参数 Map<encodehinttype, object=""> hints = new HashMap<>(); hints.put(EncodeHintType.CHARACTER_SET, "utf-8"); //容错级别 hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H); //设置空白边距的宽度 // hints.put(EncodeHintType.MARGIN, 2); //default is 4 // 图像数据转换,使用了矩阵转换 BitMatrix bitMatrix = new QRCodeWriter().encode(content, BarcodeFormat.QR_CODE, widthPix, heightPix, hints); int[] pixels = new int[widthPix * heightPix]; // 下面这里按照二维码的算法,逐个生成二维码的图片, // 两个for循环是图片横列扫描的结果 for (int y = 0; y < heightPix; y++) { for (int x = 0; x < widthPix; x++) { if (bitMatrix.get(x, y)) { pixels[y * widthPix + x] = 0xff000000; } else { pixels[y * widthPix + x] = 0xffffffff; } } } // 生成二维码图片的格式,使用ARGB_8888 Bitmap bitmap = Bitmap.createBitmap(widthPix, heightPix, Bitmap.Config.ARGB_8888); bitmap.setPixels(pixels, 0, widthPix, 0, 0, widthPix, heightPix); if (logoBm != null) { bitmap = addLogo(bitmap, logoBm); } //必须使用compress方法将bitmap保存到文件中再进行读取。直接返回的bitmap是没有任何压缩的,内存消耗巨大! return bitmap != null && bitmap.compress(Bitmap.CompressFormat.JPEG, 100, new FileOutputStream(filePath)); } catch (WriterException | IOException e) { e.printStackTrace(); } return false; } /** * 在二维码中间添加Logo图案 */ private static Bitmap addLogo(Bitmap src, Bitmap logo) { if (src == null) { return null; } if (logo == null) { return src; } //获取图片的宽高 int srcWidth = src.getWidth(); int srcHeight = src.getHeight(); int logoWidth = logo.getWidth(); int logoHeight = logo.getHeight(); if (srcWidth == 0 || srcHeight == 0) { return null; } if (logoWidth == 0 || logoHeight == 0) { return src; } //logo大小为二维码整体大小的1/5 float scaleFactor = srcWidth * 1.0f / 5 / logoWidth; Bitmap bitmap = Bitmap.createBitmap(srcWidth, srcHeight, Bitmap.Config.ARGB_8888); try { Canvas canvas = new Canvas(bitmap); canvas.drawBitmap(src, 0, 0, null); canvas.scale(scaleFactor, scaleFactor, srcWidth / 2, srcHeight / 2); canvas.drawBitmap(logo, (srcWidth - logoWidth) / 2, (srcHeight - logoHeight) / 2, null); canvas.save(Canvas.ALL_SAVE_FLAG); canvas.restore(); } catch (Exception e) { bitmap = null; e.getStackTrace(); } return bitmap; } }</encodehinttype,>
2.Activity中的使用:
/** * 二维码生成 */ public class MainActivity extends ActionBarActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //内容 final EditText contentET = (EditText) findViewById(R.id.create_qr_content); //显示二维码图片 final ImageView imageView = (ImageView) findViewById(R.id.create_qr_iv); //是否添加Logo final CheckBox addLogoCB = (CheckBox) findViewById(R.id.create_qr_addLogo); Button createQrBtn = (Button) findViewById(R.id.create_qr_btn); createQrBtn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { final String filePath = getFileRoot(MainActivity.this) + File.separator + "qr_" + System.currentTimeMillis() + ".jpg"; //二维码图片较大时,生成图片、保存文件的时间可能较长,因此放在新线程中 new Thread(new Runnable() { @Override public void run() { boolean success = QRCodeUtil.createQRImage(contentET.getText().toString().trim(), 800, 800, addLogoCB.isChecked() ? BitmapFactory.decodeResource(getResources(), R.mipmap.qr_logo) : null, filePath); if (success) { runOnUiThread(new Runnable() { @Override public void run() { imageView.setImageBitmap(BitmapFactory.decodeFile(filePath)); } }); } } }).start(); } }); } //文件存储根目录 private String getFileRoot(Context context) { if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) { File external = context.getExternalFilesDir(null); if (external != null) { return external.getAbsolutePath(); } } return context.getFilesDir().getAbsolutePath(); } }
/** * 二维码生成 */ public class MainActivity extends ActionBarActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //内容 final EditText contentET = (EditText) findViewById(R.id.create_qr_content); //显示二维码图片 final ImageView imageView = (ImageView) findViewById(R.id.create_qr_iv); //是否添加Logo final CheckBox addLogoCB = (CheckBox) findViewById(R.id.create_qr_addLogo); Button createQrBtn = (Button) findViewById(R.id.create_qr_btn); createQrBtn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { final String filePath = getFileRoot(MainActivity.this) + File.separator + "qr_" + System.currentTimeMillis() + ".jpg"; //二维码图片较大时,生成图片、保存文件的时间可能较长,因此放在新线程中 new Thread(new Runnable() { @Override public void run() { boolean success = QRCodeUtil.createQRImage(contentET.getText().toString().trim(), 800, 800, addLogoCB.isChecked() ? BitmapFactory.decodeResource(getResources(), R.mipmap.qr_logo) : null, filePath); if (success) { runOnUiThread(new Runnable() { @Override public void run() { imageView.setImageBitmap(BitmapFactory.decodeFile(filePath)); } }); } } }).start(); } }); } //文件存储根目录 private String getFileRoot(Context context) { if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) { File external = context.getExternalFilesDir(null); if (external != null) { return external.getAbsolutePath(); } } return context.getFilesDir().getAbsolutePath(); } }
3.本項目中圖片檔案保存在
context.getExternalFilesDir(null)
目錄之下的。按照官方的api文檔,從KitKat開始(Android 4.4),儲存文件到這個目錄下將不需要SD卡讀寫權限。但經過測驗表明,在紅米Note和魅族MX3上(系統均為android 4.4.4),的確不需要權限;但是在本人的華為P6上(Android 4.4.2),必須聲明權限才能成功的保存文件,即必須在manifest中添加以下內容:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"> <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"></uses-permission></uses-permission>
因此,個人猜測,所謂的不需要權限是從Android 4.4.4開始的。
下面再給大家分享Android生成二維碼及添加logo的程式碼
具體程式碼如下圖:
@Override public Bitmap generateBitmap(String content, int width, int height) { QRCodeWriter qrCodeWriter = new QRCodeWriter(); Map<EncodeHintType, String> hints = new HashMap<>(); hints.put(EncodeHintType.CHARACTER_SET, "utf-8");//默认 hints.put(EncodeHintType.MARGIN, "1");//无白色边框 try { BitMatrix encode = qrCodeWriter.encode(content, BarcodeFormat.QR_CODE, width, height, hints); int[] pixels = new int[width * height]; for (int i = 0; i < height; i++) { for (int j = 0; j < width; j++) { if (encode.get(j, i)) { pixels[i * width + j] = 0x00000000; } else { pixels[i * width + j] = 0xffffffff; } } } return Bitmap.createBitmap(pixels, 0, width, width, height, Bitmap.Config.RGB_565); } catch (WriterException e) { e.printStackTrace(); } return null; } @Override public Bitmap addLogo(Bitmap qrBitmap, Bitmap logoBitmap) { int qrBitmapWidth = qrBitmap.getWidth(); int qrBitmapHeight = qrBitmap.getHeight(); int logoBitmapWidth = logoBitmap.getWidth(); int logoBitmapHeight = logoBitmap.getHeight(); Bitmap blankBitmap = Bitmap.createBitmap(qrBitmapWidth, qrBitmapHeight, Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(blankBitmap); canvas.drawBitmap(qrBitmap, 0, 0, null); canvas.save(Canvas.ALL_SAVE_FLAG); float scaleSize = 1.0f; while ((logoBitmapWidth / scaleSize) > (qrBitmapWidth / 3.5) || (logoBitmapHeight / scaleSize) > (qrBitmapHeight / 3.5)) { scaleSize *= 2; } float sx = 1.0f / scaleSize; canvas.scale(sx, sx, qrBitmapWidth / 2, qrBitmapHeight / 2); canvas.drawBitmap(logoBitmap, (qrBitmapWidth - logoBitmapWidth) / 2, (qrBitmapHeight - logoBitmapHeight) / 2, null); canvas.restore(); return blankBitmap; }
好了,程式碼到此結束了,希望對大家有幫助!
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