为什么'onShowFileChooser' 什么都不覆盖？

Question

Tell me what I did wrong in my code, why 'onShowFileChooser' overrides nothing? The class was created to allow webview to upload files from the phone "webview import file".

class FileChooseClient(private val activity: ActivityChoser) : WebChromeClient() {
override fun onShowFileChooser(v: WebView?, fpc: ValueCallback<Uri>?, fcp: FileChooserParams): Boolean {
    if (activity.uploadMessage != null) {
        activity.uploadMessage?.onReceiveValue(null)
        activity.uploadMessage = null
    }

    activity.uploadMessage = fpc

    val intent: Intent = fcp.createIntent()
    try {
        activity.startActivityForResult(intent, ActivityChoser.REQUEST_SELECT_FILE)
        (activity as Activity).overridePendingTransition(
            android.R.anim.fade_in,
            android.R.anim.fade_out
        )
    } catch (e: ActivityNotFoundException) {
        activity.uploadMessage = null
        return false
    }

    return true
}

interface ActivityChoser {
    companion object {
        const val REQUEST_SELECT_FILE = 100;
    }
    var uploadMessage: ValueCallback<Uri>?
    fun startActivityForResult(intent: Intent, req: Int)
}

}

Answer 1

Because the second parameter's type is wrong; it should be

ValueCallback<Array<Uri>?>

or maybe

ValueCallback<Array<Uri>?>?

because a file chooser can choose multiple files ( ? after Array should definitely be there if I understand the documentation correctly).