如何在动画结束时隐藏进度条

Question

I have an activity containing a WebView and ProgressBar . During the loading of a web page, the progress bar appears and gradually horizontally fills. How can the visibility of the progress bar be set to View.GONE after the animation has finished?

public class WebviewActivity extends AppCompatActivity {
    WebView myWebView;
    ProgressBar pBar;
    ProgressBar myProgressBar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.fragment_webview);
    }

    @Override
    protected void onStart() {
        super.onStart();

        setContentView(R.layout.fragment_webview);

        myProgressBar = findViewById(R.id.mProgressBar);
        myProgressBar.setMax(100);

        String url = getIntent().getStringExtra("url");
        myWebView = findViewById(R.id.webview01);
        myWebView.setWebViewClient(new WebViewClient());
        WebSettings webSettings = myWebView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        myWebView.loadUrl(url);

        myWebView.setWebChromeClient(new WebChromeClient() {
            @Override
            public void onProgressChanged(WebView view, int newProgress) {
                super.onProgressChanged(view, newProgress);
                myProgressBar.setProgress(newProgress);

                if (newProgress == 100) {
                    AlphaAnimation fadeOut;
                    fadeOut = new AlphaAnimation(1,0);
                    fadeOut.setDuration(500);
                    fadeOut.setFillAfter(true);
                    myProgressBar.startAnimation(fadeOut);
//                    myProgressBar.setVisibility(View.GONE);
                } else {
                    myProgressBar.setVisibility(View.VISIBLE);
                }
            }
        });

    }

    private class WebViewClient extends android.webkit.WebViewClient {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request){
            String url=request.getUrl().toString();

            view.loadUrl(url);
            return true;
        }

        @Override
        public void onPageFinished(WebView view, String url) {
            super.onPageFinished(view, url);
//            myProgressBar.setVisibility(View.GONE);
        }
    }
}

Answer 1

Use a listener:

fadeOut.setAnimationListener(new Animation.AnimationListener() {
    @Override
    public void onAnimationStart(Animation animation) {}

    @Override
    public void onAnimationRepeat(Animation animation) {}

    @Override
    public void onAnimantionEnd(Animation animation) {
        myProgressBar.setVisibility(View.GONE);
    }
});

Answer 2

Try setting an animation listener to the animation object (fadeOut):

myWebView.setWebChromeClient(new WebChromeClient() {
            @Override
            public void onProgressChanged(WebView view, int newProgress) {
                super.onProgressChanged(view, newProgress);
                myProgressBar.setProgress(newProgress);

                if (newProgress == 100) {
                    AlphaAnimation fadeOut;
                    fadeOut = new AlphaAnimation(1, 0);
                    fadeOut.setDuration(500);
                    fadeOut.setFillAfter(true);
                    fadeOut.setAnimationListener(new Animation.AnimationListener() {
                        @Override
                        public void onAnimationStart(Animation animation) {
                            // whatever you want to happen when the fadeOut animation starts
                        }

                        @Override
                        public void onAnimationEnd(Animation animation) {
                            // whatever you want to happen when the fadeOut animation ends
                            myProgressBar.setVisibility(View.GONE);
                        }

                        @Override
                        public void onAnimationRepeat(Animation animation) {
                            // whatever you want to happen when the fadeOut animation repeats itself
                        }
                    });
                    myProgressBar.startAnimation(fadeOut);
                } else {
                    myProgressBar.setVisibility(View.VISIBLE);
                }
            }
        });

With the callbacks above, you can hook into AnimationStart , AnimationEnd and AnimationRepeat .