java - 从静态 fragment 调用 webview 中的 JS 函数

Question

我正在尝试有一个表格 Activity ，当我通过选择“固定选项卡 + swype”的导航类型来创建我的项目时，它会自动为我设置。在每个选项卡中，我加载一个基于选项卡更改 URL 的 webview。在一个选项卡中，虽然我想调用一个 JS 函数，该函数存在于 webview 将要访问的页面上。我尝试了各种各样的事情但没有成功，JS 函数有效但由于某种原因它没有被调用。

下面代码中的url不是我实际使用的url，这里也是引用JS函数

function callFromActivity(msg){
    document.getElementById("mytext").innerHTML = msg;
}

public class MainActivity extends FragmentActivity implements ActionBar.TabListener {

/**
 * The {@link android.support.v4.view.PagerAdapter} that will provide
 * fragments for each of the sections. We use a
 * {@link android.support.v4.app.FragmentPagerAdapter} derivative, which
 * will keep every loaded fragment in memory. If this becomes too memory
 * intensive, it may be best to switch to a
 * {@link android.support.v4.app.FragmentStatePagerAdapter}.
 */
SectionsPagerAdapter mSectionsPagerAdapter;

/**
 * The {@link ViewPager} that will host the section contents.
 */
ViewPager mViewPager;

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

    // Set up the action bar.
    final ActionBar actionBar = getActionBar();
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

    // Create the adapter that will return a fragment for each of the three
    // primary sections of the app.
    mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());

    // Set up the ViewPager with the sections adapter.
    mViewPager = (ViewPager) findViewById(R.id.pager);
    mViewPager.setAdapter(mSectionsPagerAdapter);

    // When swiping between different sections, select the corresponding
    // tab. We can also use ActionBar.Tab#select() to do this if we have
    // a reference to the Tab.
    mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
        @Override
        public void onPageSelected(int position) {
            actionBar.setSelectedNavigationItem(position);
        }
    });

    // For each of the sections in the app, add a tab to the action bar.
    for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
        // Create a tab with text corresponding to the page title defined by
        // the adapter. Also specify this Activity object, which implements
        // the TabListener interface, as the callback (listener) for when
        // this tab is selected.
        actionBar.addTab(
                actionBar.newTab()
                        .setText(mSectionsPagerAdapter.getPageTitle(i))
                        .setTabListener(this));
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
    // When the given tab is selected, switch to the corresponding page in
    // the ViewPager.
    mViewPager.setCurrentItem(tab.getPosition());
}

@Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}

@Override
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}

/**
 * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
 * one of the sections/tabs/pages.
 */
public class SectionsPagerAdapter extends FragmentPagerAdapter {

    public SectionsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        // getItem is called to instantiate the fragment for the given page.
        // Return a DummySectionFragment (defined as a static inner class
        // below) with the page number as its lone argument.
        Fragment fragment = new DummySectionFragment();
        Bundle args = new Bundle();
        args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public int getCount() {
        // Show 5 total pages.
        return 5;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        Locale l = Locale.getDefault();
        switch (position) {
            case 0:
                return getString(R.string.title_section1).toUpperCase(l);
            case 1:
                return getString(R.string.title_section2).toUpperCase(l);
            case 2:
                return getString(R.string.title_section3).toUpperCase(l);
            case 3:
                return getString(R.string.title_section4).toUpperCase(l);
            case 4:
                return getString(R.string.title_section5).toUpperCase(l);
        }
        return null;
    }
}

/**
 * A dummy fragment representing a section of the app, but that simply
 * displays dummy text.
 */
public static class DummySectionFragment extends Fragment {
    /**
     * The fragment argument representing the section number for this
     * fragment.
     */
    public static final String ARG_SECTION_NUMBER = "section_number";
    public DummySectionFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        View rootView = inflater.inflate(R.layout.fragment_main_dummy, container, false);
        View htmlView =inflater.inflate(R.layout.home_wvtc,container,false);
        WebView wc = (WebView) htmlView.findViewById(R.id.webView1);
        TextView dummyTextView = (TextView) rootView.findViewById(R.id.section_label);
        // dummyTextView.setText(Integer.toString(getArguments().getInt(ARG_SECTION_NUMBER)));
        if(getArguments().getInt(ARG_SECTION_NUMBER) == 1 )
        {

            wc.getSettings().setJavaScriptEnabled(true);
            wc.loadUrl("http://www.example.com/android/index.html");
            wc.loadUrl("javascript:callFromActivity('some msg')");

            wc.setWebViewClient(new WebViewClient(){
                public boolean shouldOverrideUrlLoading(WebView view, String url) {
                    return false;
                }
            });

            return htmlView;
        }
        if(getArguments().getInt(ARG_SECTION_NUMBER) == 2 )
        {

            wc.getSettings().setJavaScriptEnabled(true);
            wc.loadUrl("http://www.example.com/android/request.html");

            wc.setWebViewClient(new WebViewClient(){
                public boolean shouldOverrideUrlLoading(WebView view, String url) {
                    if (url != null ) {

                        return false;
                    } else {
                        return false;
                    }
                }
            });

            return htmlView;
        }
        if(getArguments().getInt(ARG_SECTION_NUMBER) == 3 )
        {

            wc.getSettings().setJavaScriptEnabled(true);
            wc.loadUrl("http://www.example.com/android/recent.html");
            wc.setWebViewClient(new WebViewClient(){
                public boolean shouldOverrideUrlLoading(WebView view, String url) {
                    if (url != null ) {

                        return false;
                    } else {
                        return false;
                    }
                }
            });
            return htmlView;
        }
        if(getArguments().getInt(ARG_SECTION_NUMBER) == 4 )
        {

            wc.getSettings().setJavaScriptEnabled(true);
            wc.loadUrl("http://www.example.com/android/queue.html");
            wc.setWebViewClient(new WebViewClient(){
                public boolean shouldOverrideUrlLoading(WebView view, String url) {
                    if (url != null ) {

                        return false;
                    } else {
                        return false;
                    }
                }
            });
            return htmlView;
        }
        if(getArguments().getInt(ARG_SECTION_NUMBER) == 5 )
        {

            wc.getSettings().setJavaScriptEnabled(true);
            wc.loadUrl("http://www.example.com/android/webcam.html");
            wc.setWebViewClient(new WebViewClient(){
                public boolean shouldOverrideUrlLoading(WebView view, String url) {
                    if (url != null ) {

                        return false;
                    } else {
                        return false;
                    }
                }
            });
            return htmlView;
        }
        else {
            return rootView;
        }
    }

 }

}

Answer 1

在执行 java 脚本之前，您应该等待文档加载完成。您可以使用 WebChromeClient 来观察加载进度。

private class MyWebChromeClient extends WebChromeClient {

    private WebView mWebView;
    public MyWebChromeClient(WebView webView)
    {
        mWebView = webView;
    }

    @Override
    public void onProgressChanged(WebView view, int newProgress) {
        super.onProgressChanged(view, newProgress);
        if (newProgress == 100) {
            mWebView.loadUrl("javascript:callFromActivity('some msg')");
        }
    }
}

将 MyWebChromeClient 设置为 WebView

wc.getSettings().setJavaScriptEnabled(true);
wc.loadUrl("http://www.example.com/android/index.html");
wc.setWebChromeClient(new MyWebChromeClient(wc));