Android应用开发：生成二维码，android应用开发,二维码这个东西自从出来后

Android应用开发：生成二维码，android应用开发,二维码这个东西自从出来后

二维码这个东西自从出来后就一直流行到现在，无论走到哪里，二维码都可能出现在你的眼前。现在智能手机基本上都有扫一扫功能，扫的就是二维码。那我们怎 么样在手机上生成个自己的二维码呢？Android开发中生成二维码不难，用Google ZXing生成二维码很简单,下面我们就简单操作一直，把最主要的代码贴出来，还请大家多指教！

第一步：

确定我们二维码的位置，即是在我们应用的哪个页面的哪个位置，简单讲就是用一个ImageView把二维码展示出来，我们就把二维码展示在下面布局activity_qr_layout中的ImageView上：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:sample="http://schemas.android.com/apk/res-auto"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:background="#dadada"    android:focusable="true"    android:focusableInTouchMode="true"    android:orientation="vertical" >            <ImageView                 android:id="@+id/qr_show"                android:layout_gravity="center_horizontal"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:layout_marginBottom="55dp"                android:scaleType="fitXY"                android:background="@null"                android:src="@drawable/default_pic"                /></LinearLayout>

接下来直接在Activity中生成二维码就可以了：

public class MyQrActivity extends Activity {private ImageView qr_show;private SampleListLinearLayout lv_record;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_qr_layout); initViews();}protected void initViews() {qr_show = (ImageView) findViewById(R.id.qr_show);DisplayMetrics outMetrics = new DisplayMetrics();getWindowManager().getDefaultDisplay().getMetrics(outMetrics);int w = outMetrics.widthPixels * 8 / 11;//设置宽度ViewGroup.LayoutParams layoutParams = qr_show.getLayoutParams();layoutParams.height = layoutParams.width = w;//设置高度qr_show.setLayoutParams(layoutParams);try {Bitmap bitmap = QRUtils.encodeToQRWidth("http://write.blog.csdn.net/", w);//要生成二维码的内容，我这就是一个网址qr_show.setImageBitmap(bitmap);}catch (Exception e) {e.printStackTrace();Toast.makeText(this, "生成二维码失败", Toast.LENGTH_SHORT);}}}

下面是生成二维码的工具类，不要忘记在项目中要导入ZXing相关的jar包：

public class QRUtils {private static final int WHITE = 0xFFFFFFFF;    private static final int BLACK = 0xFF000000;    /**     * 将字符串按照指定大小生成二维码图片     */public static Bitmap encodeToQR(String contentsToEncode, int dimension) throws Exception{if(TextUtils.isEmpty(contentsToEncode))return null;    BarcodeFormat format = BarcodeFormat.QR_CODE;    Map<EncodeHintType,Object> hints = new EnumMap<EncodeHintType,Object>(EncodeHintType.class);    hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");    BitMatrix result = new MultiFormatWriter().encode(contentsToEncode, format, dimension, dimension, hints);    int width = result.getWidth();        int height = result.getHeight();        int[] pixels = new int[width * height];        for (int y = 0; y < height; y++) {          int offset = y * width;          for (int x = 0; x < width; x++) {         pixels[offset + x] = result.get(x, y) ? BLACK : WHITE;          }        }        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);        bitmap.setPixels(pixels, 0, width, 0, 0, width, height);        return bitmap;}public static Bitmap encodeToQRWidth(String contentsToEncode, int dimension) throws Exception{if(TextUtils.isEmpty(contentsToEncode))return null;BarcodeFormat format = BarcodeFormat.QR_CODE;    Map<EncodeHintType,Object> hints = new EnumMap<EncodeHintType,Object>(EncodeHintType.class);    hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");    BitMatrix result = new MultiFormatWriter().encode(contentsToEncode, format, dimension, dimension, hints);int width = result.getWidth();int height = result.getHeight();boolean isFirstBlack = true;int startX = 0;int startY = 0;int[] pixels = new int[width * height];for (int y = 0; y < height; y++) {int offset = y * width;for (int x = 0; x < width; x++) {pixels[offset + x] = result.get(x, y) ? BLACK : WHITE;if(result.get(x, y) &amp;&amp; isFirstBlack){isFirstBlack = false;startX = x;startY = y;}}}Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);        bitmap.setPixels(pixels, 0, width, 0, 0, width, height);        Matrix m = new Matrix();float sx = (width + 2f*startX) / width;float sy = (height + 2f*startY) / height;m.postScale(sx, sy);Bitmap qrBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);Canvas canvas = new Canvas(qrBitmap);canvas.translate(-startX, -startY);Paint paint = new Paint();paint.setAntiAlias(true);canvas.drawBitmap(bitmap, m, paint);        canvas.save();        return qrBitmap;}}

ok搞定，拿去扫一扫就可以啦！