对于类型MyWebViewClient，未定义方法startActivity（Intent）

Question

I'm trying to use the Android tutorial to build an app that loads a web view to a mobile site that I built. The problem is with following the tutorial the startActivity function is undefined and the Android tutorial isn't helping. I've done Ctrl+Shift+O to verify all the proper modules are loaded.

package com.mysite;

import android.content.Intent;
import android.net.Uri;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class MyWebViewClient extends WebViewClient {
    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        if (Uri.parse(url).getHost().equals("www.mysite.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;
    }
}

Update

Ok, now my code reads:

package com.myapp;

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

public class MyApp extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        //init webview
        WebView DCWebView = (WebView) findViewById(R.id.webview);
        WebSettings webViewSettings = DCWebView.getSettings();

        //when a link is clicked, use the WebView instead of opening a new browser
        DCWebView.setWebViewClient(new MyWebViewClient() {
            @Override
            public void launchExternalBrowser(String url) {
                Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
                startActivity(intent);
            }
        });

        //enable javascript
        webViewSettings.setJavaScriptEnabled(true);

    }
}

But I'm showing 2 errors:

Description Resource    Path    Location    Type
The type new MyWebViewClient(){} must implement the inherited abstract method MyWebViewClient.launchExternalBrowser()   DealClippings.java  /MyApp/src/com/myapp    line 21 Java Problem

The method launchExternalBrowser(String) of type new MyWebViewClient(){} must override or implement a supertype method  MyApp.java  /DealClippings/src/com/myapp    line 23 Java Problem

Answer 1

There really is no startActivity method for WebViewClient . You can check the docs . You'll have to signal the Context (probably your Activity ) to execute those lines of code instead. There are many possible approaches including adding listeners or simply calling an abstract method which you implement in an anonymous instance of this class when setting the WebViewClient of your WebView in your Activity.

For example:

public abstract class MyWebViewClient extends WebViewClient {
    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        if (Uri.parse(url).getHost().equals("www.mysite.com")) {
            // This is my web site, so do not override; let my WebView load the page
            return false;
        }

        launchExternalBrowser(url);            
        return true;
    }

    public abstract void launchExternalBrowser(String url);
}

And then in your activity:

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

Although I'm not sure why you want this behavior exactly, but it should work more or less.

Answer 2

I don't know if there's much point answering your edit now, 18 months on, but it seems like this question gets a bit of traffic so I'll post this here for posterity.

From your errors, it sounds like you haven't provided an argument to the abstract method in the abstract class definition of MyWebViewClient. That is, you have this:

public abstract void launchExternalBrowser();

when you should have this:

public abstract void launchExternalBrowser(String url);

The cause of the error is that Java treats two methods with the same name but different arguments as two distinct methods. So launchExternalBrowser(String) is a different method to launchExternalBrowser() .

Hope this helps someone!

Answer 3

To answer original question before your edit..

Had the same problem, and figured out that the MyWebViewClient is meant to be an inner class inside the activity.

    package com.myapp;

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

    public class MyApp extends Activity {
        /** Called when the activity is first created. */
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);

            //init webview
            WebView DCWebView = (WebView) findViewById(R.id.webview);
            WebSettings webViewSettings = DCWebView.getSettings();

            //when a link is clicked, use the WebView instead of opening a new browser
            DCWebView.setWebViewClient(new MyWebViewClient());

            //enable javascript
            webViewSettings.setJavaScriptEnabled(true);

        }

        private class MyWebViewClient extends WebViewClient {
            @Override
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                if (Uri.parse(url).getHost().equals("www.mysite.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;
            }
        }
    }