此问题可能是由于没有正确设置WebView导致的。为了解决这个问题，我们可以尝试以下几个步骤：

1. 在AndroidManifest.xml中添加以下权限：

2. 为WebView设置WebChromeClient：

webView.webChromeClient = object : WebChromeClient() {}

3. 为WebView设置WebViewClient：

webView.webViewClient = object : WebViewClient() {}

4. 然后，您需要在onPageStarted使用Intent来启动默认浏览器：

override fun onPageStarted(view: WebView, url: String, favicon: Bitmap?) { super.onPageStarted(view, url, favicon) val intent = Intent(Intent.ACTION_VIEW, Uri.parse(url)) startActivity(intent) }

以上步骤将为您提供和WebView交互并将URL重定向到默认浏览器的完整代码示例：

class MainActivity : AppCompatActivity() {

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)

    val webView = findViewById(R.id.webView)
    webView.webChromeClient = object : WebChromeClient() {}
    webView.webViewClient = object : WebViewClient() {
        override fun onPageStarted(view: WebView, url: String, favicon: Bitmap?) {
            super.onPageStarted(view, url, favicon)
            val intent = Intent(Intent.ACTION_VIEW, Uri.parse(url))
            startActivity(intent)
        }
    }

    val qrCodeScanner = IntentIntegrator(this)
    qrCodeScanner.setDesiredBarcodeFormats(IntentIntegrator.QR_CODE)
    qrCodeScanner.setPrompt("Scan QR Code")
    qrCodeScanner.setCameraId(0)
    qrCodeScanner.setBeepEnabled(false)
    qrCodeScanner.initiateScan()
}

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    val result = IntentIntegrator.parseActivityResult(requestCode, resultCode, data)
    if (result != null) {
        if (result.contents == null) {
            Toast.makeText(this, "Cancelled", Toast.LENGTH_LONG).show()
        } else {
            val webView = findViewById(R.id.webView)
            webView.loadUrl(result.contents)
        }
    } else {
        super.onActivityResult(requestCode, resultCode, data)
    }
}

}