这似乎已经在堆栈溢出上被问了很多,但是对于SDK的更改似乎不再可以实现的答案(我可能错了!)。
我一直在尝试允许MainActivity中的片段使用硬件按钮返回片段中webview内的上一页。
我尝试过使用return super.onKeyDown(keyCode,event); 作为函数的一部分,但onKeyDown在我的项目中不会有效。
这是包含webview的BlogFragment:
public class BlogFragment extends Fragment {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
WebView wv;
private OnFragmentInteractionListener mListener;
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* @param param1 Parameter 1.
* @param param2 Parameter 2.
* @return A new instance of fragment blog.
*/
// TODO: Rename and change types and number of parameters
public static BlogFragment newInstance(String param1, String param2) {
BlogFragment fragment = new BlogFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
public static boolean canGoBack(){
return wv.canGoBack();
}
public static void goBack(){
wv.goBack();
}
public BlogFragment() {
// Required empty public constructor
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view=inflater.inflate(R.layout.fragment_blog, null);
wv = (WebView) view.findViewById(R.id.webview);
WebSettings settings = wv.getSettings();
wv.setWebChromeClient(new WebChromeClient() {
});
final String mimeType = "text/html";
final String encoding = "UTF-8";
String html = getHTML();
settings.setJavaScriptEnabled(true);
wv.loadDataWithBaseURL("http://www.bbc.co.uk", html, mimeType, encoding, "");
return view;
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
public String getHTML() {
String html = "<iframe width=\"100%\" height=\"100%\" src=\"http://blog.mrgyro.co.uk\" frameborder=\"0\" allowfullscreen></iframe>";
return html;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p/>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
public void onFragmentInteraction(Uri uri);
}
}
的活动:
public class MainActivity extends ActionBarActivity
implements NavigationDrawerFragment.NavigationDrawerCallbacks, BlogFragment.OnFragmentInteractionListener, HomeFragment.OnFragmentInteractionListener {
/**
* 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;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mNavigationDrawerFragment = (NavigationDrawerFragment)
getSupportFragmentManager().findFragmentById(R.id.navigation_drawer);
mTitle = getTitle();
// Set up the drawer.
mNavigationDrawerFragment.setUp(
R.id.navigation_drawer,
(DrawerLayout) findViewById(R.id.drawer_layout));
}
@Override
public void onBackPressed() {
if(BlogFragment.canGoBack()){
BlogFragment.goBack();
}else{
super.onBackPressed();
}
}
@Override
public void onNavigationDrawerItemSelected(int position) {
android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
android.support.v4.app.FragmentTransaction transaction = fragmentManager.beginTransaction();
switch (position) {
case 0:
HomeFragment homeFragment = new HomeFragment();
transaction.replace(R.id.container, homeFragment);
break;
case 1:
BlogFragment blogFragment = new BlogFragment();
transaction.replace(R.id.container, blogFragment);
break;
}
transaction.commit();
}
public void onSectionAttached(int number) {
switch (number) {
case 1:
mTitle = getString(R.string.title_section1);
break;
case 2:
mTitle = getString(R.string.title_section2);
break;
case 3:
mTitle = getString(R.string.title_section3);
break;
case 4:
mTitle = getString(R.string.title_section4);
break;
}
}
public void restoreActionBar() {
ActionBar actionBar = getSupportActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
actionBar.setDisplayShowTitleEnabled(true);
actionBar.setTitle(mTitle);
}
@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.main, 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.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
//if (id == R.id.action_settings) {
// return true;
// }
return super.onOptionsItemSelected(item);
}
@Override
public void onFragmentInteraction(Uri uri) {
}
/**
* 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_SECTION_NUMBER = "section_number";
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = null;
rootView = inflater.inflate(R.layout.fragment_home, container, false);
switch(getArguments().getInt(ARG_SECTION_NUMBER)) {
case 1:
rootView = inflater.inflate(R.layout.fragment_home, container, false);
break;
case 2:
rootView = inflater.inflate(R.layout.fragment_blog, container, false);
break;
case 3:
// rootView = inflater.inflate(R.layout.fragment_test, container, false);
break;
case 4:
//rootView = inflater.inflate(R.layout.fragment_info, container, false);
break;
default:
Log.e("TAG", "Unrecognized section: " + getArguments().getInt(ARG_SECTION_NUMBER));
}
return rootView;
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
((MainActivity) activity).onSectionAttached(
getArguments().getInt(ARG_SECTION_NUMBER));
}
}
}
提前致谢。
编辑:我已经用我最近的尝试更新了博客片段,但是当尝试静态wv.canGoBack()和wv.goBack()时都返回错误“非静态字段'wv'无法引用静态上下文答案 0 :(得分:1)
尝试覆盖Activity
中的onBackPressed(),然后点击WebView
。
BTW - 您也可以发布包含Activity
方法的onKeyDown
段。
编辑:不是按照你现在的方式(static
)制作方法BlogFragment.canGoBack()
,而是首先实例化片段:
BlogFragment blogFragment = new BlogFragment();
blogFragment.canGoBack();
然后从您的方法中删除static
。 :)
OPs实施(感谢Klotor) 在MainActivity的负责人实施:
BlogFragment blogFragment = new BlogFragment();
然后执行:
public void onBackPressed() {
blogFragment.canGoBack();
if(blogFragment.canGoBack()){
blogFragment.goBack();
}else{
super.onBackPressed();
}
}
片段在onBackPressed之外实例化,以防止在使用方法在片段之间导航时崩溃。 在这种情况下,您需要实例化片段的新实例,而不是一个全新的片段。
答案 1 :(得分:0)
**在OnCreateView内部的Fragment类中,将以下代码****
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
view = inflater.inflate(R.layout.your_layout, container, false);
mWebView = (WebView) view.findViewById(R.id.webView);
mWebView.getSettings().setJavaScriptEnabled(true);
mWebView.setWebViewClient(new MyWebViewClient());
mWebView.loadUrl(expertsUrl);
return view;
}
private class MyWebViewClient extends WebViewClient {
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
}
**在MainActivity类中,放在代码下面**
@Override
public void onBackPressed() {
if (WebViewFragment.mWebView!=null) {
if (WebViewFragment.mWebView.canGoBack()) {
WebViewFragment.mWebView.goBack();
}
else {
super.onBackPressed();
}
}
}
用片段替换WebViewFragment-> mWebView->使用您的Webview
希望这对您有帮助!!!!