addJavascriptInterface无法正常工作该如何解决？

Question

我正在尝试通过Javascript函数从网页“查找框”调用。吐司正常工作，但“ search（）”函数无效。我认为代码中存在一些问题。请帮我。我也在关注this文章。正常运行，但不能从网页上运行。

activity_search_demo.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

<WebView
    android:id="@+id/webview"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"/>

<LinearLayout
    android:orientation="horizontal"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/layoutId"
    android:background="@color/colorPrimary">
</LinearLayout>
</RelativeLayout>

SearchDemoActivity.java

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Color;
import android.graphics.Rect;
import android.graphics.Typeface;
import android.os.Build;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnKeyListener;
import android.view.inputmethod.InputMethodManager;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;
import java.lang.reflect.Method;

@SuppressWarnings("ALL")
public class SearchDemoActivity extends AppCompatActivity {
WebView mWebView;
private LinearLayout container;
private TextView previusButton, nextButton, closeButton, searchbtn;
private EditText findBox;

@SuppressWarnings( "deprecation" )
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_search_demo);
    mWebView = (WebView)findViewById(R.id.webview);
    mWebView.loadUrl("file:///android_asset/main.html");
    WebSettings webSettings = mWebView.getSettings();
    webSettings.setJavaScriptEnabled(true);
    mWebView.setWebViewClient( new WebViewClient() );
    mWebView.setWebChromeClient( new WebChromeClient() );
    WebSettings settings = mWebView.getSettings();
    settings.setLoadWithOverviewMode(true);
    settings.setUseWideViewPort(true);
    webSettings.setBuiltInZoomControls(true);
    webSettings.setDisplayZoomControls(false);

    mWebView.addJavascriptInterface(new JavascriptInterface(),"Searchbtn");
    mWebView.setWebChromeClient(new WebChromeClient() {
    });
}
public class JavascriptInterface {
    @android.webkit.JavascriptInterface
    public  void SearchOnclick(){
        search();
        Toast.makeText(getApplicationContext(), "You are searching.....", Toast.LENGTH_SHORT).show();
    }
}

    @SuppressLint("ResourceAsColor")
    @SuppressWarnings( "deprecation" )
public void search(){
    container = (LinearLayout)findViewById(R.id.layoutId);
    closeButton = new TextView(this);
    closeButton.setTextSize(25);
    closeButton.setText("×");
    closeButton.setTextColor(Color.parseColor("#FFFF4059"));
    closeButton.setPadding(30, 10,30,10);
    closeButton.setOnClickListener(new OnClickListener(){
        @Override
        public void onClick(View v){
            container.removeAllViews();
            findBox.getText().clear();
            mWebView.findAll(findBox.getText().toString());
        }
    });
    container.addView(closeButton);

    previusButton = new TextView(this);
    previusButton.setTextSize(25);
    previusButton.setFocusable(true);
    previusButton.setClickable(true);
    previusButton.setText("<");
    previusButton.setPadding(30, 10,30,10);
    previusButton.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            mWebView.findNext(false);
        }
    });
    container.addView(previusButton);

    nextButton = new TextView(this);
    nextButton.setTextSize(25);
    nextButton.setText(">");
    nextButton.setClickable(true);
    nextButton.setFocusable(true);
    nextButton.setPadding(30, 10,30,10);
    nextButton.setOnClickListener(new OnClickListener(){
        @Override
        public void onClick(View v){
            mWebView.findNext(true);
        }
    });
    container.addView(nextButton);

    searchbtn = new TextView(this);
    searchbtn.setTextSize(20);
    searchbtn.setText("\uD83D\uDD0D");
    searchbtn.setPadding(30, 10,0,10);
    searchbtn.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            mWebView.findAll(findBox.getText().toString());
        }
    });
    container.addView(searchbtn);

    findBox = new EditText(this);
    findBox.setMinEms(30);
    findBox.setSingleLine(true);
    findBox.setPadding(10, 10,30,10);
    findBox.setHint("Search...");

    findBox.setOnKeyListener(new OnKeyListener(){
        public boolean onKey(View v, int keyCode, KeyEvent event){
            if((event.getAction() == KeyEvent.ACTION_DOWN) && ((keyCode == KeyEvent.KEYCODE_ENTER))){
                mWebView.findAll(findBox.getText().toString());
                try{
                    Method m = WebView.class.getMethod("setFindIsUp", Boolean.TYPE);
                    m.invoke(mWebView, true);
                }catch(Exception ignored){
                }
            }
            return false;
        }
    });

    container.addView(findBox);
    }
}

javascript代码：

var search = document.getElementById('search')
search.addEventListener('click', function(){
 Searchbtn.SearchOnclick()
})