Develop Reference

WebView goback() method does not work

I have a requirement in my app where I need to render the multiple web pages in webview and provide the goback() method.
But unfortunately goback() method does not work in the case when we load the url(one of the url from multiple pages) which does not exit(Web page not available)and then we try to call the goBack()

it seems you complicate your code you just try simple code below
#Override
public void onBackPressed() {
if (webView.canGoBack()) {
webView.goBack();
} else {
super.onBackPressed();
}
}
this is simple code work fine for you,i dont know if you are using flag for other reasons.

You can do like this.
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK && webView.canGoBack()) {
webView.goBack();
return true;
}
return super.onKeyDown(keyCode, event);
}
And you Web page not available,you can use onReceivedError method.
webView.setWebViewClient(new WebViewClient() {
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
#TargetApi(Build.VERSION_CODES.M)
#Override
public void onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) {
super.onReceivedError(view, request, error);
if (request.isForMainFrame()) {
// you can do something when you Web page not available
// webView.goBack();
}
}
});

Android web-view not working properly on device back press

Hi I am developing android in which I am using web-view. My web-view has more than one pages inside that. So my intended functionality is like that when I press device back button it should return to previous web url and when it on last web page it should close that activity and come to previous activity. I tried it in following way which works fine on new devices but not working properly on older android versions.My code looks like:
webView = new WebView(this);
webView.setWebViewClient(new WebViewClient() {
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
if (url.contains(URLManager.URL_DICOM_BACK_PRESSED_URL)) {
processBackPressed();
return true;
} else {
return super.shouldOverrideUrlLoading(view, url);
}
}
#Override
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
if (failingUrl.contains(URLManager.URL_DICOM_BACK_PRESSED_URL)) {
processBackPressed();
} else {
showError("Server unreachable");
}
}
#Override
public void onPageFinished(WebView view, String url) {
super.onPageFinished(view, url);
runOnUiThread(new Thread() {
#Override
public void run() {
super.run();
if(!webviewLoaded) {
webviewLoaded = true;
content.removeAllViews();
content.setOrientation(LinearLayout.VERTICAL);
// LLM.addInParent(content, textView, -1001, -999, 0);
LLM.addInParent(content, webView, -1001, 0, 1);
}
}
});
}
});
webView.getSettings().setJavaScriptEnabled(true);
webView.loadUrl(url);
#Override
public void onBackPressed() {
if (webView != null && webView.canGoBack()) {
webView.goBack();
} else {
processBackPressed();
}
}
public void processBackPressed() {
super.onBackPressed();
finish();
}
Above code works fine one new android versions but not working on older versions.
What I observe shouldOverrideUrlLoading not works on older versions.
Am I doing anything wrong? Need some help. Thank you.

stop page to redirect when user press back key in webview android

public void onBackPressed (){
WebView webview = (WebView) findViewById(R.id.mainWebView);
if (webview.isFocused() && webview.canGoBack()) {
webview.goBack();
}
else {
super.onBackPressed();
finish();
}
}
private class MyCustomWebViewClient extends WebViewClient {
ProgressDialog progressDialog = new ProgressDialog(AndroidMobileAppSampleActivity.this);
#Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
super.onPageStarted(view, url, favicon);
progressDialog.setMessage("Processing");
progressDialog.setCancelable(false);
progressDialog.setOnKeyListener(new OnKeyListener(){
#Override
public boolean onKey(DialogInterface dialog, int keyCode,
KeyEvent event) {
if(keyCode == KeyEvent.KEYCODE_SEARCH) {
return true;
}
else
return false;
}});
progressDialog.show();
}
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
progressDialog.setMessage("Processing");
progressDialog.setCancelable(false);
progressDialog.setOnKeyListener(new OnKeyListener(){
#Override
public boolean onKey(DialogInterface dialog, int keyCode,
KeyEvent event) {
if(keyCode == KeyEvent.KEYCODE_SEARCH) {
return true;
}
else
return false;
}});
progressDialog.show();
view.loadUrl(url);
return true;
}
public void onPageFinished(WebView view, String url) {
if (progressDialog.isShowing()) {
progressDialog.dismiss();
}
}
}
This is my code, i am loading a url in webview and showing a processing dialog when user redirect to another page, Now i want to stop my page to redirect and also hide processing dialog when user press the back key. I tried but not successful, Please help. Thanks in advance

Clear history on finished page load.
No back history.
mWebView.setWebViewClient(new WebViewClient(){
#Override
public void onPageFinished(WebView view, String url)
{
mWebView.clearHistory();
super.onPageFinished(view, url);
}
});

Webview cannot go back with local html

I have a webview that load up a URL from internet, but when there is no connectivity (onReceiedError) it loads up a locally saved html document in assets folder.
but when I press back button on that particular activity (which loads up the local HTML) it doesn't go back to the previous activity instead tries to refresh the page.. It is only after 4-5 Back presses it goes back.
here is my code.
private class HelloWebViewClient extends WebViewClient{
#Override
public void onReceivedError(WebView view, int errorCode,
String description, String failingUrl) {
mWebView.getSettings().setBuiltInZoomControls(false);
mWebView.getSettings().setLoadWithOverviewMode(false);
mWebView.getSettings().setUseWideViewPort(false);
mWebView.loadUrl("file:///android_asset/offline.html");
}
public boolean shouldOverrideUrlLoading(WebView webview, String url)
{
webview.loadUrl(url);
return true;
}
}
#Override
public boolean onKeyDown(int KeyCode, KeyEvent event)
{
if ((KeyCode)== KeyEvent.KEYCODE_BACK && mWebView.canGoBack())
{
mWebView.goBack();
return true;
}
return super.onKeyDown(KeyCode, event);
}
#Override
public void onBackPressed()
{
this.finish();
overridePendingTransition (0, R.anim.right_slide_out);
return;
}
}
Works fine with the normal webpage to load from Internet.

coz in onReceivedError you change the url . so there will be no goback event
you have to just show toast message and delete mWebView.loadUrl("file:///android_asset/offline.html");

How to control the Android WebView history/back stack?

I am trying to figure out a way to handle the WebView back stack similar to how the Android web browser handles it when the back button is pressed from within my own app's WebView.
The problem has to do with Javascript redirects. The WebView back stack appears to contain URLs that simply redirect. Here is my relevant code:
private class ArticleWebViewClient extends WebViewClient {
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
}
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK)
{
WebView wv = (WebView)findViewById(R.id.web);
if (wv.canGoBack())
{
wv.goBack();
return true;
}
}
return super.onKeyDown(keyCode, event);
}
As you can see, pressing the back button selects the previous URL in the stack, which loads in the WebView itself after shouldOverrideUrlLoading() is called. I'm actually doing a lot more inside shouldOverrideUrlLoading() that isn't relevant for this particular question, so "remove my WebViewClient implementation" won't work for me. At any rate, when the previous URL is a Javascript redirect, that URL loads and then Javascript immediately redirects to the URL the WebView was just at. I can't disable Javascript because the website depends on it. I also can't change the website (third-party).
The result of this redirection issue is a vicious cycle for the end-user who is frantically pressing back just to be slightly faster than the Android webpage processing engine.
Now here is where it gets interesting: The Android web browser handles the back button just fine for Javascript redirects! It follows the redirects just fine but the back button does what a user expects it to do. That means it is possible to correctly handle this scenario. How does the Android web browser handle this problem?

Detect when url loading is triggered by the user, and add those to the backstack instead.
private List<String> previous = new ArrayList<String>();
private String mLastUrl;
webview.setWebViewClient(new WebViewClient() {
#Override
public void onPageFinished(WebView view, String url) {
Log.i("DebugDebug", "OnPageFinished " + url);
mLastUrl = url;
super.onPageFinished(view, url);
}
});
webview.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View view, MotionEvent motionEvent) {
WebView.HitTestResult hr = ((WebView)view).getHitTestResult();
if (hr != null && mLastUrl != null) {
if (previous.isEmpty() || !previous.get(previous.size() - 1).equals(mLastUrl)) {
previous.add(mLastUrl);
}
Log.i("DebugDebug", "getExtra = " + hr.getExtra() + "\t\t Type = " + hr.getType());
}
return false;
}
});
#Override
public void onBackPressed() {
Log.i("DebugDebug", "onBackPressed");
int size = previous.size();
if (size > 0){
webview.loadUrl(previous.get(size - 1));
previous.remove(size - 1);
} else {
super.onBackPressed();
}
}

your onKeyDown should look like these
#Override
public boolean onKeyDown(int keyCode, KeyEvent event)
{
if ((keyCode == KeyEvent.KEYCODE_BACK) && myWebView.canGoBack()) {
myWebView.goBack();
return true;
}
return super.onKeyDown(keyCode, event);
}
here myWebView is declared in the Activity's onCreate

I had a similar problem with yours and found how to figure it out. Here is my answer.
When I click the first link(www.new.a) it automatically redirects other link(mobile.new.a). Usually the links redirect two or three, and my solution have been worked on almost every redirect links. I hope this answer help you out with annyoing redirecting links.
I finally figured out that. You need a WebViewClient with four APIs. There are shouldOverrideUrlLoading(), onPageStarted(), onPageFinished(), and doUpdateVisitedHistory() in the WebViewClient. All the APIs you need is API 1 so don't worry about.
Here is my answer. Check out that! :)

The correct answer is to return false on shouldOverrideUrlLoading() as described in https://stackoverflow.com/a/8644978/5022858 and https://developer.android.com/reference/android/webkit/WebViewClient.html. This prevents redirects from being added to the history list.

private class ArticleWebViewClient extends WebViewClient {
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
return false;
}
}
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK)
{
WebView wv = (WebView)findViewById(R.id.web);
if (wv.canGoBack())
{
wv.goBack();
return true;
}
}
return super.onKeyDown(keyCode, event);
}
This shouldOverrideUrlLoading method should return false if you want to handle the link in your webview rather than system browser, and do not call view.loadUrl(url), your webview will load url automatically if you return false. The history will be not correct if you load url manually.

boolean isGoBack = false; //back key is pressed
private long goBackTime = 0; //
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if ((keyCode == KeyEvent.KEYCODE_BACK) && mWebView.canGoBack()) {
isGoBack = true;
goBackTime = System.currentTimeMillis();
mWebView.goBack();
return true;
}
return super.onKeyDown(keyCode, event);
}
Webview mWebView.
setWebViewClient(new WebViewClient() { //setWebViewClient
#Override
public boolean shouldOverrideUrlLoading (WebView view, String url){
if (!TextUtils.isEmpty(startUrl) && !startUrl.equals(url) && isGoBack && System.currentTimeMillis() - goBackTime < 600) {
isGoBack = false;
if (mWebView.canGoBack()) {
mWebView.goBack();
} else {
finish(); //activity finish
}
} else {
view.loadUrl(url);
isGoBack = false;
return true;
}
return false;
}
#Override
public void onPageStarted (WebView view, String url, Bitmap favicon){
super.onPageStarted(view, url, favicon);
startUrl = url;
}
}

this snippet work for me, try it:
#Override
public void onBackPressed() {
BlankFragment fragment = (BlankFragment)
getSupportFragmentManager().findFragmentByTag("webView");
if (fragment.canGoBack()) {
fragment.goBack();
} else {
super.onBackPressed();
}
}