Android- Webview onPageFinished 调用了两次

Question

我有一个 Activity 通过拦截重定向 url 一旦它显示在 web View 中来进行 OAuth 身份验证。但是，由于某种原因，onPageFinished 函数被调用了两次，这真的弄乱了我的应用程序。代码如下:

public class WebViewActivity extends Activity {
private WebView gWebView;
final String REDIRECT_URI = "https://localhost:5000/receive_code";
final String CLIENT_ID = "can't post it here";
final String CLIENT_SECRET = "can't post it here";
final String SCOPE = "basic names genomes analyses";
Hashtable<String, String> riskPairs;

public void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);
    setContentView(R.layout.webview);

    gWebView = (WebView) findViewById(R.id.webView1);

    gWebView.loadUrl("https://api.23andme.com/authorize/?redirect_uri="
            + REDIRECT_URI + "&response_type=code&client_id=" + CLIENT_ID
            + "&scope=" + SCOPE);

    Log.d("WEBVIEW", "got to webpage");

    gWebView.setWebViewClient(new WebViewClient() {

        @Override
        public void onPageFinished(WebView view, String url) {
            super.onPageFinished(view, url);
            if (url.startsWith(REDIRECT_URI)) {
                Log.d("WEBVIEW", "onpagefinished is called");
                System.out.println("got to override");
                if (url.indexOf("code=") != -1) {
                    //if the query contains code
                    String queryString = null;
                    try {
                        queryString = new URL(url).getQuery();
                    } catch (MalformedURLException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    System.out.println(queryString);
                    String[] params = queryString.split("&");
                    String code = null;
                    for (String param : params) {
                        if (param.startsWith("code=")) {
                            code = param.substring(param.indexOf('=') + 1);
                        }
                    }
                    gWebView.setVisibility(View.GONE);
                    new PostRequest().execute(code);
                    // don't go to redirectUri
                }
            }
        }
    });


}
class PostRequest extends AsyncTask<String,Void,String>{ code getting client data...}

附:请不要将此标记为重复...我在 StackOverflow 上阅读了一个类似的问题，并且调用 ShouldOverrideUrlLoading 对我不起作用(这就是我首先使用 onPageFinished() 的原因)。

Answer 1

如果onPageStarted方法启动onPageFinished后url是OK的，但是如果url之后重定向onPageStarted 开始 shouldOverrideUrlLoading 然后 onPageFinished。您应该只检查加载 URL 是否被重定向

private boolean isRedirected;

@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {   

  if (!isRedirected) {      
    //Do something you want when starts loading
  }

  isRedirected = false;
}

如果 URL 被重定向，回调将启动此函数

@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {

  view.loadUrl(url);
  isRedirected = true;
  return true;
}

在 onPageFinished 做某事之前检查回调是否进入了 shouldOverrideUrlLoading 方法

@Override
public void onPageFinished(WebView view, String url) {

  if (!isRedirected) {
    //Do something you want when finished loading 
  }
}