为什么我不能注入这个JavaScript在Android上的web视图？ [英] Why can't I inject this javascript in the webview on android?

问题描述

在我的应用我加载网页视图。该网站我加载在这个WebView中，有一个菜单按钮，但我不想显示此。所以我写了下面的code。然而，这不是工作，我不知道为什么...

In my app I'm loading a webview. The website I'm loading in this webview, has a menu button, but I don't want to display this. So I wrote the code below. However, this isn't working and I don't know why...

{

        @Override
        public void onPageFinished(WebView view, String url)
        {
            // when a page has finished loading dismiss any progress dialog
            if (progressDialog != null && progressDialog.isShowing())
            {
                progressDialog.dismiss();
                String javascript="javascript: document.getElementById('menu-toggle').css('display','none');";
                myWebView.loadUrl(javascript);
            }
        }
    });

更新：这是仍然不工作，我似乎无法找到什么错完整的Java文件：

UPDATE: Here's the complete java file that still isn't working, I just can't seem to find what's going wrong:

package test.firstapp;

import android.app.Activity;
import android.app.ProgressDialog;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;


public class login
    extends ActionBarActivity
    implements NavigationDrawerFragment.NavigationDrawerCallbacks
{

/**
 * Fragment managing the behaviors, interactions and presentation of the
 * navigation drawer.
 */
private NavigationDrawerFragment mNavigationDrawerFragment;

/**
 * Used to store the last screen title. For use in
 * {@link #restoreActionBar()}.
 */
private CharSequence mTitle;

// we need a class level references to some objects to be able to modify the
//   target address outside of onCreate()
private WebView myWebView;
private ActionBar actionBar;
private ProgressDialog progressDialog;

// keep the pair of String arrays of site names and addresses
private String[] siteNames;
private String[] siteAddresses;

private static final String TAG = "MainActivity";

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

    // grab the needed website arrays
    siteNames = getResources().getStringArray(R.array.site_names);
    siteAddresses = getResources().getStringArray(R.array.site_addresses);

    // set up WebView. initial page load comes from NavDrawerFragment attach
    myWebView = (WebView) findViewById(R.id.main_webview);
    myWebView.getSettings().setJavaScriptEnabled(true);
    myWebView.setWebChromeClient(new WebChromeClient());
    myWebView.setWebViewClient(new WebViewClient()
    {

        @Override
        public void onPageFinished(WebView view, String url)
        {
            // when a page has finished loading dismiss any progress dialog
            if (progressDialog != null && progressDialog.isShowing())
            {
                progressDialog.dismiss();
            }
            String javascript="javascript:"+
                                        "document.getElementById('menu-toggle').css('display','none');";
            myWebView.evaluateJavascript(javascript, null);
        }
    });

    // Set up the drawer.
    mNavigationDrawerFragment = (NavigationDrawerFragment) getSupportFragmentManager()
            .findFragmentById(R.id.navigation_drawer);
    mNavigationDrawerFragment.setUp(R.id.navigation_drawer,
            (DrawerLayout) findViewById(R.id.drawer_layout));
}

@Override
public void onNavigationDrawerItemSelected(int siteIndex)
{
    // user selected page load
    Log.d(TAG, "(onNavSelect) received index: " + siteIndex);
    loadWebPage(siteIndex);
}

public void onSectionAttached(int siteIndex)
{
    // initial page load. not user selected.
    loadWebPage(siteIndex);
}

public void restoreActionBar()
{
    actionBar = getSupportActionBar();
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
    actionBar.setDisplayShowTitleEnabled(true);
    actionBar.setTitle(mTitle);
}

private void loadWebPage(int siteIndex)
{
    // lets show a progress indicator instead of a blank screen
    if (progressDialog == null)
    {
        initProgressDialog();
    }
    progressDialog.show();

    // load the page
    Log.d(TAG, "(loadWebPage) Loading page: " + siteNames[siteIndex] + "("
            + siteAddresses[siteIndex] + ")");
    mTitle = siteNames[siteIndex];
    if (actionBar == null)
    {
        restoreActionBar();
    }
    else
    {
        actionBar.setTitle(mTitle);
    }
    myWebView.getSettings().setJavaScriptEnabled(true);
    myWebView.loadUrl(siteAddresses[siteIndex]);
    myWebView.loadUrl(siteAddresses[siteIndex]);

    // progressDialog gets dismissed above in WebViewclient declaration
}

private void initProgressDialog()
{
    progressDialog = new ProgressDialog(this, ProgressDialog.STYLE_SPINNER);
    progressDialog.setIndeterminate(true);
    progressDialog.setMessage(getString(R.string.page_load_progress_message));
}


@Override
public boolean onCreateOptionsMenu(Menu menu)
{
    if (!mNavigationDrawerFragment.isDrawerOpen())
    {
        // Only show items in the action bar relevant to this screen
        // if the drawer is not showing. Otherwise, let the drawer
        // decide what to show in the action bar.
        getMenuInflater().inflate(R.menu.global, menu);
        restoreActionBar();
        return true;
    }
    return super.onCreateOptionsMenu(menu);
}

@Override
public boolean onOptionsItemSelected(MenuItem item)
{
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    if (actionBar == null)
    {
        restoreActionBar();
    }
    else
    {

    }
    int id = item.getItemId();
    if (id == R.id.action_settings)
    {
        myWebView.loadUrl("settings");
        myWebView.loadUrl("settings");
        actionBar.setTitle("Settings");
        return true;
    }
    return super.onOptionsItemSelected(item);
}

/**
 * A placeholder fragment containing a simple view.
 */
public static class PlaceholderFragment
        extends Fragment
{

    /**
     * The fragment argument representing the section number for this
     * fragment.
     */
    private static final String ARG_SELECTED_SITE_INDEX = "selected_site_index";

    /**
     * Returns a new instance of this fragment for the given section
     * number.
     */
    public static PlaceholderFragment newInstance(int siteIndex)
    {
        PlaceholderFragment fragment = new PlaceholderFragment();
        Bundle args = new Bundle();
        args.putInt(ARG_SELECTED_SITE_INDEX, siteIndex);
        fragment.setArguments(args);
        return fragment;
    }

    public PlaceholderFragment()
    {}

    @Override
    public View onCreateView(LayoutInflater inflater,
                             ViewGroup container,
                             Bundle savedInstanceState)
    {
        View rootView = inflater.inflate(R.layout.fragment_login, container, false);
        return rootView;
    }

    @Override
    public void onAttach(Activity activity)
    {
        super.onAttach(activity);
        // Here is where you can define the default page you want loaded
        //  or if you want to save/restore the last page viewed etc.
        ((login) activity)
                .onSectionAttached(getArguments().getInt(ARG_SELECTED_SITE_INDEX));
    }
}

}

推荐答案

在Android 4.4或以上版本，你需要<一个href=\"http://developer.android.com/reference/android/webkit/WebView.html#evaluateJavascript%28java.lang.String,%20android.webkit.ValueCallback%3Cjava.lang.String%3E%29\"相对=nofollow>使用 evaluateJavascript（） ，而不是使用loadURL（JavaScript的：...），作为您在的WebView执行JavaScript的方式。

On Android 4.4+, you need to use evaluateJavascript(), not loadUrl("javascript:..."), as your way of executing JavaScript in a WebView.

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