我在片段容器中有一个 webview，我在其中嵌入了后退功能。它适用于使用设备后退按钮在 web 视图中进行导航。但是，当我单击设备返回按钮退出片段时说我打开包含新闻的片段 1，然后打开包含此 web 视图的片段 2，然后单击设备返回按钮返回新闻片段，它不起作用，它必须返回到应用程序的主页。这是我正在使用的代码类。我不知道该怎么做，我是否必须编辑一些 backpressed() 函数？如果是这样，我该怎么做，或者有一种方法可以创建 if(goingback)，返回 -1 以返回 1 步。有任何想法吗？
谢谢！贾斯汀
@SuppressLint("ValidFragment")
public class MoneyWebViewFragment extends Fragment implements OnClickListener , MainActivity.BackPressListener<Fragment> {
private static final String SEARCH_TERM = "search_term";
private static String mSearchTerm;
private WebView mWebview;
private static MoneyWebViewFragment sUserProfileManager;
public boolean mIsMoneyFragment;
public final static String SYMBOL = "symbol";
public static int PIC_WIDTH = 30;
private static final String SYMBOL_TYPE = "symbol_type";
public static final String CONTAINER_ID = "container_id";
public static final String TAG_Money_FRAGMENT_WEBVIEW = "MoneyWebViewFragment";
SharedPreferencesManager manager = SharedPreferencesManager.getInstance();
private static String URL;
private final String USERNAME = manager.getLoginUsername();
private final String PASSWORD = manager.getDecryptedLoginPassword();
LinearLayout progressBar;
private static MoneyWebViewFragment __newInstance(final MoneyWebViewFragment fragment, final FragmentManager manager,
final String searchTerm, final String symbolType, int containerViewId, final int inAnimation, final int outAnimation, final int popInAnimation, final int popOutAnimation) {
final Bundle bundle = new Bundle();
bundle.putString(SEARCH_TERM, searchTerm);
bundle.putString(MoneyWebViewFragment.SYMBOL_TYPE, symbolType);
bundle.putInt(MoneyWebViewFragment.CONTAINER_ID, containerViewId);
fragment.setArguments(bundle);
FragmentInfo fragmentInfo = new FragmentInfo(TransactionMethods.ADD, containerViewId);
fragmentInfo.setAnimation(inAnimation, outAnimation);
fragmentInfo.setPopAnimation(popInAnimation, popOutAnimation);
fragmentInfo.setFragmentTag(TAG_Money_FRAGMENT_WEBVIEW);
fragmentInfo.setActionBarTitle(Application.getAppResources().getString(R.string.title_search));
FragmentStackManager.getInstance().transitionFragment(manager, fragment, fragmentInfo);
URL = getUrl();
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Bundle bundle = this.getArguments();
URL = getUrl();
if(bundle != null)
mSearchTerm = getArguments().getString(SEARCH_TERM);
}
public void setSearchTerms(String sTerms){
mSearchTerm = sTerms;
}
public static void removeInstance(final FragmentManager manager) {
final MoneyWebViewFragment fragment = (MoneyWebViewFragment) manager.findFragmentByTag(TAG_Money_FRAGMENT_WEBVIEW);
if (fragment == null) {
return;
}
final FragmentStackManager stackManager = FragmentStackManager.getInstance();
if (stackManager.getTopFragment() instanceof MoneyWebViewFragment) {
stackManager.popTopFragment();
}
}
private boolean goingBack = false;
private boolean onBackPressClearStack = true;
public void setOnBackPressClearStack(boolean b){
onBackPressClearStack = b;
}
public boolean webViewSteppedBack() {
if (mWebview != null && mWebview.canGoBack()) {
WebBackForwardList mWebBackForwardList = mWebview.copyBackForwardList();
String historyUrl = mWebBackForwardList.getItemAtIndex(mWebBackForwardList.getCurrentIndex()-1).getUrl();
mWebview.goBack();
return true;
}
return false;
}
private MoneyWebViewFragment() {
mIsMoneyFragment = false;
}
public static synchronized void clearUserProfileManager() {
sUserProfileManager = new MoneyWebViewFragment();
}
public static MoneyWebViewFragment getInstance() {
if (sUserProfileManager == null) {
sUserProfileManager = new MoneyWebViewFragment();
}
return sUserProfileManager;
}
public boolean isMoneyWebViewFragment() {
return mIsMoneyFragment;
}
@Override
public boolean backPressed(final MainActivity mainActivity) {
if (webViewSteppedBack()) {
return true;
}
if (onBackPressClearStack) {
goingBack = true;
FragmentUtils.onBackPressedKnockFragsOffStack(mainActivity, this);
}
return false;
}
private static String getUrl(){
String url = "";
final String environmentApi = SharedPreferencesManager.getInstance().getEnvironmentApi();
if (environmentApi.equalsIgnoreCase(NetworkUtils.Apis.ALPHA)) {
url = "https://abc.com?q="+mSearchTerm+"userAgent=android";
}
return url;
}
private static MoneyWebViewFragment __newInstance(final MoneyWebViewFragment fragment, final FragmentManager manager,
final String searchTerm, final String symbolType, int containerViewId) {
return __newInstance(fragment, manager,searchTerm, symbolType, containerViewId, R.anim.slide_in_from_right, R.anim.slide_out_to_left, R.anim.slide_in_from_left, R.anim.slide_out_to_right);
}
private static void clearWebView(final FragmentManager manager) {
final MoneyWebViewFragment fragment = (MoneyWebViewFragment) manager.findFragmentByTag(TAG_Money_FRAGMENT_WEBVIEW);
if (fragment != null && fragment instanceof MoneyWebViewFragment) {
((MoneyWebViewFragment)fragment).clearWebView();
}
}
public static MoneyWebViewFragment newInstance(final FragmentManager manager, final String searchTerm, String symbolType) {
clearWebView(manager);
return __newInstance(new MoneyWebViewFragment(), manager, searchTerm, symbolType, R.id.fragment_container);
}
public static MoneyWebViewFragment newInstance(final FragmentManager manager, final String searchTerm, String symbolType, int containerViewId) {
clearWebView(manager);
return __newInstance(new MoneyWebViewFragment(), manager, searchTerm, symbolType, containerViewId);
}
public static MoneyWebViewFragment newInstanceNoBackPressed(final FragmentManager manager, final String searchTerm, final String symbolType, int containerViewId) {
MoneyWebViewFragment fragment = __newInstance(new MoneyWebViewFragment(), manager, searchTerm, symbolType, containerViewId);
fragment.setOnBackPressClearStack(false);
return fragment;
}
public static MoneyWebViewFragment newInstanceNoBackPressed(final MoneyWebViewFragment fragment, final FragmentManager manager, final String searchTerm, final String symbolType, int containerViewId) {
fragment.setOnBackPressClearStack(false);
return __newInstance(fragment, manager, searchTerm, symbolType, containerViewId);
}
public static MoneyWebViewFragment newInstanceForSearch(final FragmentManager manager, final String searchTerm, String symbolType) {
MoneyWebViewFragment fragment = __newInstance(new MoneyWebViewFragment(), manager, searchTerm, symbolType, R.id.fragment_container, R.anim.no_animation, R.anim.slide_out_to_right, R.anim.slide_in_from_right, R.anim.slide_out_to_right);
return fragment;
}
@Override
public void onResume() {
super.onResume();
final MainActivity activity = (MainActivity) getActivity();
activity.updateActionBarTitle();
activity.setBackPressListener(this);
}
public void clearWebView() {
if (mWebview != null) {
mWebview.removeAllViews();
mWebview.destroy();
mWebview = null;
}
}
@Override
public void onClick(View v) {
}
@SuppressWarnings("deprecation")
@SuppressLint({
"SetJavaScriptEnabled", "NewApi"
})
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
if (goingBack) {
return null;
}
final MainActivity activity = (MainActivity) getActivity();
activity.setBackPressListener(this);
View view = inflater.inflate(R.layout.fragment_search_Money, container, false);
mWebview = (WebView)view.findViewById(R.id.webview);
progressBar = (LinearLayout) view.findViewById(R.id.loading);
mWebview.setVisibility(View.VISIBLE);
progressBar.setVisibility(View.VISIBLE);
mWebview.setWebViewClient(new MyWebViewClient(this, mWebview));
mWebview.getSettings().setUseWideViewPort(true);
//mWebview.getSettings().setDefaultZoom(ZoomDensity.CLOSE);
//mWebview.getSettings().setBuiltInZoomControls(false);
//mWebview.getSettings().setSupportZoom(false);
mWebview.setBackgroundColor(0);
mWebview.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
mWebview.getSettings().setAllowFileAccess(true);
mWebview.getSettings().setDomStorageEnabled(true);
mWebview.getSettings().setJavaScriptEnabled(true);
mWebview.setScrollbarFadingEnabled(false);
mWebview.getSettings().getLoadsImagesAutomatically();
mWebview.setWebChromeClient(new WebChromeClient() {
@Override
public void onReceivedTitle(WebView view, String title) {
super.onReceivedTitle(view, title);
String serverError = "412";
if (title.contains(serverError)) {
view.stopLoading();
SearchResultsFragment.newInstance(getFragmentManager(), mSearchTerm);
}
}
});
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
mWebview.getSettings().setDisplayZoomControls(false);
SharedPreferencesManager mgr = SharedPreferencesManager.getInstance();
CookieStore cookieStore = mgr.getCookieStore();
Cookie cookie = cookieStore.getCookies().get(0);
String cookieString = cookie.getName() + "=" + cookie.getValue() + "; domain=" + cookie.getDomain();
CookieManager cookieMgr = CookieManager.getInstance();
cookieMgr.setCookie(URL, cookieString);
mWebview.loadUrl(URL);
return view;
}
public class MyWebViewClient extends WebViewClient {
//private String loginCookie;
private int rIdParent_id = -1;
public void setRIdParent_id (int id) {
rIdParent_id= id;
}
public MyWebViewClient(MoneyWebViewFragment MoneyWebViewFragment, WebView webview) {
super();
}
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
view.setVisibility(View.VISIBLE);
}
@Override
public void onPageFinished(WebView view, String url) {
view.setVisibility(View.VISIBLE);
final Animation fade = new AlphaAnimation(0.0f, 1.0f);
fade.setDuration(200);
view.startAnimation(fade);
progressBar.setVisibility(View.GONE);
}
@Override
public void onReceivedError( WebView view, int errorCode, String description, String failingUrl ) {
Toast.makeText(view.getContext(), "Authentication Error", Toast.LENGTH_LONG).show();
// CookieManager cookieManager = CookieManager.getInstance();
//cookieManager.setCookie(USERNAME, PASSWORD);
super.onReceivedError(view, errorCode, description, failingUrl);
}
@Override
public void onLoadResource( WebView view, String url ){
}
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
return super.shouldOverrideUrlLoading(view, url);
}
@Override
public void onReceivedHttpAuthRequest( WebView view, final HttpAuthHandler handler, final String host, final String realm ){
// CookieManager cookieManager = CookieManager.getInstance();
//cookieManager.setCookie(USERNAME, PASSWORD);
handler.proceed(USERNAME,PASSWORD);
}
@Override
public void onReceivedSslError( WebView view, SslErrorHandler handler, SslError error ) {
handler.proceed();
}
}
/* @Override
public void onDetach() {
super.onDetach();
// mView.removeView(mWebview);
// mWebview.removeAllViews();
QuotesFragmentWebView.newInstanceNoBackPressed(getFragmentManager(), mSearchTerm, "goog msft", -1);
// mWebview.destroy();
}*/
}