在片段中调用意图 WebView

Question

嗨，我正在尝试在单击 recyclerview 项目时调用 webview 片段，我用它的 webview 布局制作了一个片段，我有一个适配器来调用该片段，但它关闭了 APP：

public class WebViewFragment extends Fragment {

    public WebView mWebView;


    public WebViewFragment() {
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment

        mWebView = (WebView) mWebView.findViewById(R.id.webview);
        mWebView.loadUrl("google.com");

        // Enable Javascript
        WebSettings webSettings = mWebView.getSettings();
        webSettings.setJavaScriptEnabled(true);

        // Force links and redirects to open in the WebView instead of in a browser
        mWebView.setWebViewClient(new WebViewClient());

        return inflater.inflate(R.layout.fragment_web_view, container, false);
    }

}

还有适配器：

@Override
    public void onClick(View view) {
        int position = (int) view.getTag();
        News news =newsItems.get(position);
        Uri uri = Uri.parse(news.getLink());
        Intent intent = new Intent(mACtivity, WebViewFragment.class);
        mACtivity.startActivity(intent);

    }

布局：

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="tech.amro.amro.WebViewFragment">

    <!-- TODO: Update blank fragment layout -->

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

</FrameLayout>

我知道我还没有将 url 发送到 webview，但我只是在测试先加载视图然后发送 url。但是当单击该项目时，它会关闭 APP。并给出这个错误：

D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: tech.amro.amro, PID: 18958
                  android.content.ActivityNotFoundException: Unable to find explicit activity class {tech.amro.amro/tech.amro.amro.WebViewFragment}; have you declared this activity in your AndroidManifest.xml?
                      at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1932)
                      at android.app.Instrumentation.execStartActivity(Instrumentation.java:1615)
                      at android.app.Activity.startActivityForResult(Activity.java:4472)
                      at android.support.v4.app.BaseFragmentActivityApi16.startActivityForResult(BaseFragmentActivityApi16.java:54)
                      at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:67)
                      at android.app.Activity.startActivityForResult(Activity.java:4430)
                      at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:720)
                      at android.app.Activity.startActivity(Activity.java:4791)
                      at android.app.Activity.startActivity(Activity.java:4759)
                      at tech.amro.amro.adapters.NewsAdapter.onClick(NewsAdapter.java:73)
                      at android.view.View.performClick(View.java:6256)
                      at android.view.View$PerformClick.run(View.java:24701)
                      at android.os.Handler.handleCallback(Handler.java:789)
                      at android.os.Handler.dispatchMessage(Handler.java:98)
                      at android.os.Looper.loop(Looper.java:164)
                      at android.app.ActivityThread.main(ActivityThread.java:6541)
                      at java.lang.reflect.Method.invoke(Native Method)
                      at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
Application terminated.

Answer 1

如果您没有使用 WebView 的特定原因，您可以使用 Intent 来启动 Web 浏览器，如下所示。

@Override
public void onClick(View view) {
    int position = (int) view.getTag();
    News news = newsItems.get(position);
    Intent i = new Intent(Intent.ACTION_VIEW);
    i.setData(Uri.parse(news.getLink()));
    startActivity(i);
}

请注意，您可能需要检查设备是否可以处理 URI - 有些人可能没有安装浏览器，这会导致 ActivityNotFoundException。

如果您确实需要使用 WebView，您会遇到几个问题：

Fragment 不能以启动 Activity 的方式启动，要显示 Fragment，您需要使用 FragmentManager 将其添加到 Activity 中。

关于您的片段，onCreateView 代码将不起作用。您需要先膨胀包含您的 webview 的 xml，然后从该布局中找到 webview。 目前您正试图从 webView 中找到 webView，这将导致 NullPointerException。 您还应该更喜欢 onViewCreated 来查找和加载 WebView url。

您的片段应该如下所示

public class WebViewFragment extends Fragment {

    private static final String NEWS_LINK_KEY = "NEWS_LINK";
    private String newsLink;

    public static WebViewFragment newInstance(String uri) {
        Bundle args = new Bundle();
        args.putString(NEWS_LINK_KEY, uri);
        WebViewFragment webViewFragment = new WebViewFragment();
        webViewFragment.setArguments(args);
        return webViewFragment;
    }

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        newsLink = this.getArguments().getString(NEWS_LINK_KEY);
    }

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.web_view, container, false)
    }

    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        WebView webView = (WebView) view.findViewById(R.id.webview);

        // Enable Javascript
        WebSettings webSettings = webView.getSettings();
        webSettings.setJavaScriptEnabled(true);

        // Force links and redirects to open in the WebView instead of in a browser
        webView.setWebViewClient(new WebViewClient());

        webView.loadUrl(newsLink);
    }
}

这可以从 onClick 方法开始，如下所示：

@Override
public void onClick(View view) {
    int position = (int) view.getTag();
    News news = newsItems.get(position);
    getSupportFragmentManager().beginTransaction()
            .add(android.R.id.content, WebViewFragment.newInstance(news.getLink()))
            .commit();
}