/** * 二維碼生成工具類 */public class QRCodeUtil { /**  * 生成二維碼Bitmap  *  * @param content 內容  * @param widthPix 圖片寬度  * @param heightPix 圖片高度  * @param logoBm 二維碼中心的Logo圖標（可以為null）  * @param filePath 用于存儲二維碼圖片的文件路徑  * @return 生成二維碼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;   }   //配置參數   Map<encodehinttype, object=""> hints = new HashMap<>();   hints.put(EncodeHintType.CHARACTER_SET, "utf-8");   //容錯級別   hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);   //設置空白邊距的寬度//   hints.put(EncodeHintType.MARGIN, 2); //default is 4   // 圖像數據轉換，使用了矩陣轉換   BitMatrix bitMatrix = new QRCodeWriter().encode(content, BarcodeFormat.QR_CODE, widthPix, heightPix, hints);   int[] pixels = new int[widthPix * heightPix];   // 下面這里按照二維碼的算法，逐個生成二維碼的圖片，   // 兩個for循環是圖片橫列掃描的結果   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;     }    }   }   // 生成二維碼圖片的格式，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);   }   //必須使用compress方法將bitmap保存到文件中再進行讀取。直接返回的bitmap是沒有任何壓縮的，內存消耗巨大！   return bitmap != null && bitmap.compress(Bitmap.CompressFormat.JPEG, 100, new FileOutputStream(filePath));  } catch (WriterException | IOException e) {   e.printStackTrace();  }  return false; } /**  * 在二維碼中間添加Logo圖案  */ private static Bitmap addLogo(Bitmap src, Bitmap logo) {  if (src == null) {   return null;  }  if (logo == null) {   return src;  }  //獲取圖片的寬高  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大小為二維碼整體大小的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,>

/** * 二維碼生成 */public class MainActivity extends ActionBarActivity {  @Override protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.activity_main);   //內容  final EditText contentET = (EditText) findViewById(R.id.create_qr_content);  //顯示二維碼圖片  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";     //二維碼圖片較大時，生成圖片、保存文件的時間可能較長，因此放在新線程中    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();    }  }); }  //文件存儲根目錄 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(); }}

context.getExternalFilesDir(null)

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"><uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"></uses-permission></uses-permission>

@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");//默認   hints.put(EncodeHintType.MARGIN, "1");//無白色邊框  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; }