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;
@Override
protected 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) && 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！
原文地址：http://blog.csdn.net/true100/article/details/44001315
