Web Sayfasında Önceki Sayfaya Dön

Question

Bir web görüntülem fragmanım var ve bir önceki sayfaya geri dönmek için dahili Android geri düğmesini kullanmak istiyorum. I) (bu yapıyor ve this.getActivity.onBackPressed arayarak()

@Override 
    public void onBackPressed() { 
     Fragment webview = getFragmentManager().findFragmentByTag("webview"); 
     if (webview instanceof MyKYFB) { 
      boolean goback = ((MyKYFB) webview).web.canGoBack(); 
      if (!goback) { 
       super.onBackPressed(); 
      } else { 
       ((MyKYFB) webview).web.goBack(); 
      } 
     } 
    } 

onBackPressed geçersiz kıldık bu fragman yüklenir benim ana aktivitede

package kyfb.android.kyfb.com.kyfb; 

import android.app.Fragment; 
import android.content.Context; 
import android.content.Intent; 
import android.content.SharedPreferences; 
import android.graphics.Bitmap; 
import android.net.Uri; 
import android.os.Bundle; 
import android.view.KeyEvent; 
import android.view.LayoutInflater; 
import android.view.Menu; 
import android.view.MenuInflater; 
import android.view.MenuItem; 
import android.view.View; 
import android.view.ViewGroup; 
import android.webkit.WebChromeClient; 
import android.webkit.WebSettings; 
import android.webkit.WebView; 
import android.webkit.WebViewClient; 
import android.widget.ProgressBar; 
import android.widget.Toast; 

/** 
* Created by Adam Rayborn on 8/25/14. 
*/ 
public class MyKYFB extends Fragment { 

    public WebView web; 
    private ProgressBar progressBar; 

    private String url; 

    private static final String SP_LAST_WEBVIEW_URL = "com.app.kyfb.LASTWEBVIEWURL"; 

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
     super.onCreateView(inflater, container, savedInstanceState); 
     View rootView = inflater.inflate(R.layout.fragment_my_kyfb, null); 

     url = "https://my.kyfb.com"; 

     web = (WebView)rootView.findViewById(R.id.kyfb_web); 
     progressBar = (ProgressBar)rootView.findViewById(R.id.prgPageLoading); 

     web.getSettings().setDomStorageEnabled(true); 
     web.getSettings().setJavaScriptEnabled(true); 
     web.getSettings().setSupportZoom(true); 
     web.getSettings().setBuiltInZoomControls(true); 
     web.getSettings().setRenderPriority(WebSettings.RenderPriority.HIGH); 
     web.getSettings().setCacheMode(WebSettings.LOAD_NO_CACHE); 
     web.getSettings().setDefaultZoom(WebSettings.ZoomDensity.FAR); 


     SharedPreferences sharedPrefs = getActivity().getPreferences(Context.MODE_PRIVATE); 
     String savedUrl = sharedPrefs.getString("URL", null); 
     if (savedUrl != null) { 
      web.loadUrl(savedUrl); 
     } 
     else { 
      web.loadUrl(url); 
     } 

     web.setWebChromeClient(new WebChromeClient() { 
      public void onProgressChanged(WebView webView, int progress) { 
       getActivity().setProgress(progress * 100); 
       progressBar.setProgress(progress); 
      } 
     }); 

     // this.getView().setFocusableInTouchMode(true); 
     rootView.setFocusableInTouchMode(true); 

     web.setWebViewClient(new WebViewClient() { 
      @Override 
      public void onPageStarted(WebView view, String url, Bitmap favicon) { 
       super.onPageStarted(web, url, favicon); 
       progressBar.setVisibility(View.VISIBLE); 
      } 

      @Override 
      public void onPageFinished(WebView view, String url) { 
       super.onPageFinished(web, url); 
       progressBar.setProgress(0); 
       progressBar.setVisibility(View.GONE); 

       SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE); 
       SharedPreferences.Editor editor = sharedPref.edit(); 
       editor.putString("URL", web.getUrl()); 
       editor.apply(); 
      } 

      public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) { 
       Toast.makeText(getActivity(), description, Toast.LENGTH_SHORT).show(); 
      } 



      public boolean shouldOverrideUrlLoading(WebView view, String url) 
      { 
       if(url.endsWith(".mp4") || url.endsWith(".3gp") || url.endsWith(".avi") || url.endsWith(".flv") || url.endsWith(".pdf")){ 
        Intent i = new Intent(Intent.ACTION_VIEW); 
        i.setData(Uri.parse(url)); 
        startActivity(i); //warning no error handling will cause force close if no media player on phone. 
        return true; 
       } 

       view.loadUrl(url); 
       return true; 
      } 
     }); 

     this.getActivity().onBackPressed(); 

     return rootView; 
    } 
} 

; Parçada, geri düğmesi hiçbir şey yapmaz, ancak bir tane varsa önceki sayfaya gitmez. Fragment

Etkinlik İçin

@Override 
public void onBackPressed() { 
     Fragment webview = getSupportFragmentManager().findFragmentByTag("webview"); 
     if (webview instanceof MyWebViewFragment) { 
       boolean goback = ((MyWebViewFragment)webview).canGoBack(); 
       if (!goback) 
       super.onBackPressed(); 
     } 
} 

, için

Answer 1

According to this link

sadece

imports ....; 

    public WebView myWebView; 

    public class MainActivity extends AppcompatActivity { 
    .. 
    protected void onCreate(Bundle savedInstanceState) { 
WebView myWebView = (WebView) findViewById(R.id.webview); 

    ..} 


    @Override 
    public boolean onKeyDown(int keyCode, KeyEvent event) { 
     // Check if the key event was the Back button and if there's history 
     if ((keyCode == KeyEvent.KEYCODE_BACK) && myWebView.canGoBack()) { 
      myWebView.goBack(); 
      return true; 
     } 
     // If it wasn't the Back key or there's no web page history, bubble up to the default 
     // system behavior (probably exit the activity) 
     return super.onKeyDown(keyCode, event); 
    } 
    }