CODEWITHSUNDEEP
javaandroideclipseubuntu
Snehal Parmar
Snehal Parmar

Reputation: 5823

Android and java

The Back button on android application doesn't work in android 2.3 and developing an application on eclipse and ubuntu system, My emulator also doesn't have an back button enabled, I can't figure out what is not working as even when create an apk and install my mobile it doesn't works ? please help me with this issue.

MainActivity.java:

import android.app.Activity;
import android.view.KeyEvent;
import android.view.Menu;
import android.webkit.WebSettings;
import android.webkit.WebSettings.LayoutAlgorithm;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class MainActivity extends Activity {

    private WebView myWebView;



    @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);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        WebView myWebView = (WebView) findViewById(R.id.webview);
        //myWebView.loadUrl("http://www.example.com");

        //WebView myWebView = (WebView) findViewById(R.id.webview);
        myWebView.setWebViewClient(new WebViewClient());

        //setting JS to work in html pages in app
        WebSettings webSettings = myWebView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        //myWebView.setInitialScale(50);
        myWebView.getSettings().setLayoutAlgorithm(LayoutAlgorithm.SINGLE_COLUMN);
        myWebView.loadUrl("file:///android_asset/www/testhtml5.html");
        //mWebView.loadUrl("http://beta.html5test.com/");
    }


    @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;
    }

}

Upvotes: 0

Views: 98

Answers (2)

learner
learner

Reputation: 3110

@Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if(event.getAction() == KeyEvent.ACTION_DOWN){
            switch(keyCode)
            {
            case KeyEvent.KEYCODE_BACK:
                if(mWebView.canGoBack() == true){
                    mWebView.goBack();
                }else{
                    finish();
                }
                return true;
            }

        }
        return super.onKeyDown(keyCode, event);
    }

Edit:

put this statement:

WebView myWebView;

inside of your Activity before the onCreate() method and you should be good to go.

Upvotes: 3

Tim Kranen
Tim Kranen

Reputation: 4222

In order to add custom functionality to the back button you need to override the OnBackPressed in your activity. Like this:

 @Override
 public void onBackPressed() {
   //your custom actions
 }

Upvotes: 1

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