Android保存二维码图片到相册

在项目中可能会有保存网页生成二维码，然后将二维码图片保存到相册的需求，这里就写了一个demo，做了这样的功能，效果图如下：

首先，引入二维码zxing库：

    implementation 'com.google.zxing:zxing-parent:3.4.1'
    implementation 'com.google.zxing:core:3.3.3'

点击生成二维码图片：

    /**
     * 生成二维码图片
     *
     * @param str 二维码内容
     * @return
     */
    private fun createBitcode(str: String?): Bitmap? {
        var bitmap: Bitmap? = null
        var result: BitMatrix? = null
        val multiFormatWriter = MultiFormatWriter()
        try {
            result = multiFormatWriter.encode(str, BarcodeFormat.QR_CODE, 260, 260)
            val w: Int = result.width
            val h: Int = result.height
            val pixels = IntArray(w * h)
            for (y in 0 until h) {
                val offset = y * w
                for (x in 0 until w) {
                    pixels[offset + x] = if (result.get(x, y)) Color.BLACK else Color.WHITE
                }
            }
            bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888)
            bitmap.setPixels(pixels, 0, w, 0, 0, w, h)
        } catch (e: WriterException) {
            e.printStackTrace()
        } catch (e: IllegalArgumentException) {
            e.printStackTrace()
        }
        return bitmap
    }

点击保存二维码图片到相册：

        btnSave?.setOnClickListener {
            ivQrCode?.let { iv->
                saveBitmap(iv.drawable!!.toBitmap(iv.width, iv.height, Bitmap.Config.RGB_565), editText?.text.toString())
            }
        }

    /**
     * 将bitmap保存到相册
     */
    private fun saveBitmap(bitmap: Bitmap, url: String) {
        try {
            val path: String = getFilePath()
            if (!TextUtils.isEmpty(path)) {
                val name = path + File.separator + handleFileName(url) + ".jpg"
                val fos = FileOutputStream(name)
                if (bitmap.compress(CompressFormat.WEBP, 100, fos)) {
                    fos.flush()
                    fos.close()
                    bitmap.recycle()
                } else {
                    Toast.makeText(applicationContext, "保存失败", Toast.LENGTH_SHORT).show()
                }
            } else {
                Toast.makeText(applicationContext, "白村失败", Toast.LENGTH_SHORT).show()
            }
        } catch (e: FileNotFoundException) {
            Toast.makeText(applicationContext, "保存失败", Toast.LENGTH_SHORT).show()
        }
    }

    /**
     * 获取相册截图文件夹，这里将截图保存到/DCIM/Screenshots/路径
     */
    private fun getFilePath(): String {
        val sdCardExist = Environment.getExternalStorageState() == Environment.MEDIA_MOUNTED
        if (sdCardExist) {
            val path = Environment.getExternalStorageDirectory().toString() + "/DCIM/Screenshots/"
            val dir = File(path)
            if (!dir.exists()) {
                dir.mkdirs()
            }
            return dir.absolutePath
        }
        return ""
    }

这里将保存的文件名对一些符号就行截取：

    private fun handleFileName(s: String): String? {
        var res = s
        res.replace("\\s*".toRegex(), "")
        if (res.contains("/")) {
            res = res.substring(0, s.indexOf("/"))
        }
        if (res.contains("-")) {
            res = res.substring(0, s.indexOf("-"))
        }
        if (res.contains(":")) {
            res = res.substring(0, s.indexOf(":"))
        }
        return res
    }