当Webview应用到达特定页面时，如何用Java编写代码，应该使用android后退按钮退出该应用？

Question

I'm trying to write code in java when the webview reaches a specific page for example index it should exit the app but I failed till now.

here is my code:-

 @Override
public void onBackPressed() {
    if (mWebView.canGoBack()) {
        mWebView.goBack();
    } else {
        String url = "file:///android_asset/www/index.html" ;
        if (url.startsWith("file:///android_asset/www/index.html")) {
            new AlertDialog.Builder(this)
                    .setIcon(android.R.drawable.ic_dialog_alert)
                    .setTitle("Exit!")
                    .setMessage("Are you sure you want to close?")
                    .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            finish();
                        }

                    })
                    .setNegativeButton("No", null)
                    .show();

        }


    }
}

Update:- Problem has been solved

here is what I did:-

    @Override
public void onBackPressed() {
        String url = mWebView.getUrl();;
        if (url.equals("file:///android_asset/www/index.html")) {
            new AlertDialog.Builder(this)
                    .setIcon(android.R.drawable.ic_dialog_alert)
                    .setTitle("Exit!")
                    .setMessage("Are you sure you want to close?")
                    .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            finish();
                        }

                    })
                    .setNegativeButton("No", null)
                    .show();

        }
    else {
            mWebView.goBack();
    }
}

hope it will help someone in future

Answer 1

You have used finish. finish() only finishes the current activity, and not all the activity.

So u either have to finish all the previous activities of the application, as when u finish from this activity it exits from application.

Otherwise , u don't have a process to exit from the application. Remember, exit() doesn't work in android.