Question

    package com.webview;

    import android.app.Activity;
    import android.content.Intent;
    import android.net.Uri;
    import android.os.Bundle;
    import android.webkit.WebView;
    import android.webkit.WebViewClient;


    public class Webview_integrationActivity extends Activity {


        /** Called when the activity is first created. */
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);

            WebView mywebview = (WebView) findViewById(R.id.webView1);
            mywebview.setWebViewClient(new MyWebViewClient());



        WebViewClient client = new MyWebViewClient()
        {
            @Override
            public void launchExternalBrowser(String url) {
                 Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
                 startActivity(intent);
            }

        };
    }
    }


***************************************************************************************


package com.webview;


import android.content.Intent;
import android.net.Uri;

import android.webkit.WebView;
import android.webkit.WebViewClient;

public abstract  class MyWebViewClient extends WebViewClient {

    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        if (Uri.parse(url).getHost().equals("www.google.com")) {
            // This is my web site, so do not override; let my WebView load the page
            return false;
        }
        // Otherwise, the link is not for a page on my site, so launch another Activity that handles URLs
        Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));

        launchExternalBrowser(url);    

        return true;

}

    public abstract void launchExternalBrowser(String url);



}

**当我运行这个程序时，我得到错误为“无法实例化MyWebViewClient类型”。我知道这是因为该类是抽象的。但是如何解决我的问题。我已经粘贴了这两个类的代码我正在使用。

Answer 1

首先：您无法实例化抽象类。你只能扩展一个抽象类。

第二：创建自己的WebViewClient类（MyWebViewClient）需要什么。您可以在主活动中使用webViewClient覆盖shouldOverrideUrlLoading（WebView视图，String url）方法，并在此方法中使用launchExternalBrowser（String url）方法执行相同的操作。

我的意思是你在launchExternalBrowser（String url）方法中触发了一个intent，它是从shouldOverrideUrlLoading（WebView视图，String url）方法调用的。那你为什么不在shouldOverrideUrlLoading（WebView视图，字符串url）方法内部触发相同的Intent itselft。

Answer 2

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Button;


public class Webview_integrationActivity extends Activity {


    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        final WebView mywebview = (WebView) findViewById(R.id.webView1);
        mywebview.setWebViewClient(new WebViewClient());

        Button button1 = (Button) findViewById(R.id.My_btn);
        button1.setOnClickListener(new OnClickListener() {

                     @Override
                     public void onClick(View v) {



                          startActivity(new Intent(
                                       "android.intent.action.VIEW",
                                        Uri.parse("https://www.google.com")));
                           // TODO Auto-generated method stub
                          }

              });

    }
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            if (Uri.parse(url).getHost().equals("www.google.com")) {
                // This is my web site, so do not override; let my WebView load the page
                return false;
            }
            // Otherwise, the link is not for a page on my site, so launch another Activity that handles URLs
            Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));

            startActivity(intent);

            return true;

    }

}

无法实例化MyWebViewClient类型

2 个答案: