首先需要依赖ZXing的核心库compile 'com.google.zxing:core:3.2.1'
查看最新的ZXing release版本
新建生成二维码的工具类：
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) || content.length() < 1) {
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.L);
//设置空白边距的宽度
hints.put(EncodeHintType.MARGIN, 0); //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;
}
}
在Activity中使用：
@OnClick(R.id.btn_create_qrcode)
public void onClick() {
final File outputPic = makeTempFile(mContext, Environment.getExternalStorageDirectory().getPath() + "/uerb/test/", "qr_", ".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(mEtQrcodeContent.getText().toString().trim(), mIvQrcodeImage.getWidth(), mIvQrcodeImage.getWidth(), null, outputPic.getAbsolutePath());
if (success) {
runOnUiThread(new Runnable() {
@Override
public void run() {
mIvQrcodeImage.setImageBitmap(BitmapFactory.decodeFile(outputPic.getAbsolutePath()));
}
});
}
}
}).start();
}
@SuppressWarnings({"ConstantConditions", "ResultOfMethodCallIgnored"})
public static File makeTempFile(@NonNull Context context, @Nullable String saveDir, String prefix, String extension) {
if (saveDir == null)
saveDir = context.getExternalCacheDir().getAbsolutePath();
final String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss", Locale.getDefault()).format(new Date());
final File dir = new File(saveDir);
dir.mkdirs();
return new File(dir, prefix + timeStamp + extension);
}
常用的生成二维码的一些配置：
Map<EncodeHintType, Object> hints = new HashMap<>();
//指定字符集
hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
//容错级别，容错级别越高生成的二维码越复杂
hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);
//设置空白边距的宽度
hints.put(EncodeHintType.MARGIN, 0); //default is 4
