当我点击电话或电子邮件链接时，Android WebView 中的 ERR_UNKNOWN_URL_SCHEME

如何解决当我点击电话或电子邮件链接时，Android WebView 中的 ERR_UNKNOWN_URL_SCHEME

我使用 Web View 将我的网站转换为 Android 应用程序，我的网站有使用 tel: 创建的呼叫按钮或使用 mailto: 等创建的电子邮件按钮。它们在网络上运行良好，但在应用程序上，单击按钮，它显示 net:: ERR_UNKNowN_URL_SCHEME 并且电子邮件不会打开邮件应用程序或电话号码不会将访问者带到电话拨号器，我尝试了几种代码使其工作。喜欢

public void onPageStarted(WebView view,String url,Bitmap favicon) {  
         progressbar.setVisibility(View.VISIBLE);  
         tooltext.setText(mywebview.getUrl());  
         invalidateOptionsMenu();  
         final String Urls = url;  
   
         if(Urls.contains("mailto:") || Urls.contains("sms:") || Urls.contains("tel:") )  
         {  
           mywebview.stopLoading();  
           Intent i = new Intent();  
           i.setAction(Intent.ACTION_VIEW);  
           i.setData(Uri.parse(Urls));  
           startActivity(i);  
         }  
   
         super.onPageStarted(view,url,favicon);  
       }  

但它不起作用，我在上述代码的第一行、第二行和最后一行收到三个错误。

这是我的 MainActivity.java 页面的代码：

package com.zikrainfotech.arshadmadani;

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.Bitmap;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.webkit.WebView;
import android.webkit.WebViewClient;

import androidx.appcompat.app.AppCompatActivity;
import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;

public class MainActivity extends AppCompatActivity {

    String websiteURL = "https://arshadmadani.com/"; // sets web url
    private WebView webview;
    SwipeRefreshLayout mySwipeRefreshLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if( ! CheckNetwork.isInternetAvailable(this)) //returns true if internet available
        {
            //if there is no internet do this
            setContentView(R.layout.activity_main);
            //Toast.makeText(this,"No Internet Connection,Chris",Toast.LENGTH_LONG).show();

            new AlertDialog.Builder(this) //alert the person kNowing they are about to close
                    .setTitle("No internet connection available")
                    .setMessage("Please Check you're Mobile data or Wifi network.")
                    .setPositiveButton("Ok",new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog,int which) {
                            finish();
                        }
                    })
                    //.setNegativeButton("No",null)
                    .show();

        }
        else
        {
            //Webview stuff
            webview = findViewById(R.id.webView);
            webview.getSettings().setJavaScriptEnabled(true);
            webview.getSettings().setDomStorageEnabled(true);
            webview.setoverScrollMode(WebView.OVER_SCROLL_NEVER);
            webview.loadUrl(websiteURL);
            webview.setWebViewClient(new WebViewClientDemo());

        }

        //Swipe to refresh functionality
        mySwipeRefreshLayout = (SwipeRefreshLayout)this.findViewById(R.id.swipeContainer);

        mySwipeRefreshLayout.setonRefreshListener(
                new SwipeRefreshLayout.OnRefreshListener() {
                    @Override
                    public void onRefresh() {
                        webview.reload();
                    }
                }
        );
    }


    private class WebViewClientDemo extends WebViewClient {
        @Override
        //Keep webview in app when clicking links
        public boolean shouldOverrideUrlLoading(WebView view,String url) {
            view.loadUrl(url);
            return true;
        }
        @Override
        public void onPageFinished(WebView view,String url) {
            super.onPageFinished(view,url);
            mySwipeRefreshLayout.setRefreshing(false);
        }
    }

    //set back button functionality
    @Override
    public void onBackpressed() { //if user presses the back button do this
        if (webview.isFocused() && webview.canGoBack()) { //check if in webview and the user can go back
            webview.goBack(); //go back in webview
        } else { //do this if the webview cannot go back any further

            new AlertDialog.Builder(this) //alert the person kNowing they are about to close
                    .setTitle("EXIT")
                    .setMessage("Are you sure. You want to close this app?")
                    .setPositiveButton("Yes",int which) {
                            finish();
                        }
                    })
                    .setNegativeButton("No",null)
                    .show();
        }
    }
}

class CheckNetwork {

    private static final String TAG = CheckNetwork.class.getSimpleName();

    public static boolean isInternetAvailable(Context context)
    {
        NetworkInfo info = (NetworkInfo) ((ConnectivityManager)
                context.getSystemService(Context.CONNECTIVITY_SERVICE)).getActiveNetworkInfo();

        if (info == null)
        {
            Log.d(TAG,"no internet connection");
            return false;
        }
        else
        {
            if(info.isConnected())
            {
                Log.d(TAG," internet connection available...");
                return true;
            }
            else
            {
                Log.d(TAG," internet connection");
                return true;
            }

        }
    }
}

任何人都可以告诉我要添加什么代码以及在哪里添加代码，以便打开我应用上的电话/电子邮件/WhatsApp 链接/按钮。