How to make to webview returns to the previous page and does not show about: blank?

P.S my English very bad and I have mistakes in text))) please sorry!

How to make to webview returns to the previous page and does not show about: blank? here is my code:

@Override
    public void onBackPressed() {
        if (mWebView.canGoBack()) {
            mWebView.goBack();
            return;
        }
        else {
            finish();
        }

        super.onBackPressed();
    }
 @Override
        public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
            mbErrorOccured = true;
            showErrorLayout();
            super.onReceivedError(view, errorCode, description, failingUrl);
            loadErrorPage();
        }
    }

    private void showErrorLayout() {
        mlLayoutRequestError.setVisibility(View.VISIBLE);
    }

    private void loadErrorPage() {
        if(mWebView!=null){
            String htmlData ="<html><body><div align= center >Check your internet!</div></body>" ;
            mWebView.loadUrl("about:blank");
            mWebView.loadDataWithBaseURL(null,htmlData, "text", "utf-8",null);
            mWebView.invalidate();
        }
    }

For example, the Google page loaded, then an error occurred and about: blank was loaded, and when the page is reloaded, the WebView reloads about: blank and not the Google page. How to make the Google page load on reload?

Solution

If about:blank page is already loaded and then you are reloading webview by calling webView.reload(), it will just reload the current page i.e. about:blank.

If you want to load previous page, just call webView.goBack() or you can directly load the url like this -> webView.loadUrl("<your.web.url>")

Use WebViewClient and WebChromeClient if you want to have a better control on webview.

See the code below

First create WebViewClient and assign it to webview.

var currentUrl : String = "https://www.google.com";
webview.webViewClient = MyWebViewClient()

In WebViewClient's shouldOverrideUrlLoading method, you can have you own logic to decide which web page you want's to load.

 class MyWebViewClient : WebViewClient(){
        override fun onReceivedError(
            view: WebView?,
            request: WebResourceRequest?,
            error: WebResourceError?
        ) {
            super.onReceivedError(view, request, error)
            // here display your custom error message with retry feature
            displayErrorDialog()
        }
        override fun shouldOverrideUrlLoading(view: WebView?, url: String?): Boolean {

            // update current url

            if (url != null) {
                currentUrl = url
            }

            return super.shouldOverrideUrlLoading(view, url)
        }
    }