在 onPageFinished 后等待几秒钟

Question

i have developed a Webview App. While loading WebView, an Splash Screen as "Progressbar" is shown. But I see the Splash Screen only 1 seconds because the Splashscreen are hidden after successful load of webview. The loading is very fast but i want to see the splash screen for 3 seconds. How can I implement it in a way that the splashscreen is shown for min 3 seconds?

MainActivity:

public class MainActivity extends AppCompatActivity {

    String ShowOrHideWebViewInitialUse = "show";
    private WebView webview ;
    private ImageView spinner;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getDelegate().setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO);
        setContentView(R.layout.activity_main);

        webview =(WebView)findViewById(R.id.webView);
        spinner = (ImageView)findViewById(R.id.logo_id3);
        webview.setWebViewClient(new CustomWebViewClient());

        webview.getSettings().setJavaScriptEnabled(true);
        webview.getSettings().setDomStorageEnabled(true);
        webview.setOverScrollMode(WebView.OVER_SCROLL_NEVER);
        webview.loadUrl("xxxxxxxxxx");

    }
    boolean doubleBackToExitPressedOnce = false;

    @Override
    public void onBackPressed() {
        if (webview.canGoBack()){
            webview.goBack();
            Toast.makeText( this, "Going back inside a WebView", Toast.LENGTH_SHORT).show();
        }else {
            this.doubleBackToExitPressedOnce = true;
            Toast.makeText(this, "Doppelt zurück um zu beenden", Toast.LENGTH_SHORT).show();
        }

            if (doubleBackToExitPressedOnce) {
            super.onBackPressed();
            return;
        }



        new Handler(Looper.getMainLooper()).postDelayed(new Runnable() {
            @Override
            public void run() {
                // Your Code
                doubleBackToExitPressedOnce=false;
            }
        }, 2000);
    }

    // This allows for a splash screen
    // (and hide elements once the page loads)
    private class CustomWebViewClient extends WebViewClient {

        @Override
        public void onPageStarted(WebView webview, String url, Bitmap favicon) {

            // only make it invisible the FIRST time the app is run
            if (ShowOrHideWebViewInitialUse.equals("show")) {
                webview.setVisibility(webview.INVISIBLE);
            }
        }

        @Override
        public void onPageFinished(WebView view, String url) {

            ShowOrHideWebViewInitialUse = "hide";
            spinner.setVisibility(View.GONE);

            view.setVisibility(webview.VISIBLE);
            super.onPageFinished(view, url);

        }
    }
}

Answer 1

mWebView.setWebViewClient(new WebViewClient() {

   public void onPageFinished(WebView view, String url) {
        // Hide the splash here 
    }
}); 

Answer 2

In your case, you can delay your code this way:

public void onPageFinished(WebView view, String url) {

    Thread.sleep(2000);

    ShowOrHideWebViewInitialUse = "hide";
    spinner.setVisibility(View.GONE);

    view.setVisibility(webview.VISIBLE);
    super.onPageFinished(view, url);

}

The unit for 2000 is milliseconds. So this will pause the thread for 2 seconds and then continue

Or use the handler class like so:

public void onPageFinished(WebView view, String url) {

    new Handler().postDelayed(new Runnable() {

        @Override
        public void run() {
            ShowOrHideWebViewInitialUse = "hide";
            spinner.setVisibility(View.GONE);

            view.setVisibility(webview.VISIBLE);
            super.onPageFinished(view, url);

        }
    }, 2000);
}

Answer 3

You can use a Handler with postDelayed

Here the code in postDelayed will execute after 3 seconds from calling onPageFinished

@Override
public void onPageFinished(WebView view, String url) {
    new Handler().postDelayed(new Runnable() {
        @Override
        public void run() {
            ShowOrHideWebViewInitialUse = "hide";
            spinner.setVisibility(View.GONE);

            view.setVisibility(webview.VISIBLE);
            super.onPageFinished(view, url);

        }
    }, 3000); // 3 seconds (3000 millisec)
}