WebView 内视频的全屏按钮不起作用

Question

我正在尝试实现 WebChromeClient 的子类，以便在 youtube 上拥有一个工作全屏按钮，在 WebView 内嵌入视频链接（例如：https://www.youtube.com/embed/dQw4w9WgXcQ）。

我基本上简化了this repo，这里有一些sn-ps：

VideoWebChromeClient：

public class VideoWebChromeClient extends WebChromeClient {
    private boolean isVideoFullscreen = false;
    private View activityNonVideoView;
    private ViewGroup activityVideoView;
    private View videoViewContainer;
    private CustomViewCallback videoCallback;
    private Window videoWindow;

    public VideoWebChromeClient(View activityNonVideoView, ViewGroup activityVideoView, Window window) {
        this.activityNonVideoView = activityNonVideoView;
        this.activityVideoView =  activityVideoView;
        this.videoWindow = window;
    }

    @Override
    public void onShowCustomView(View view, CustomViewCallback callback) {
        Log.w("ENTER FULLSCREEN");
        videoCallback = callback;
        videoViewContainer = view;
        videoWindow.addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN | WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
        activityNonVideoView.setVisibility(View.GONE);
        activityVideoView.addView(videoViewContainer, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
        activityVideoView.setVisibility(View.VISIBLE);
        isVideoFullscreen = true;
    }

    @Override
    public void onHideCustomView() {
        if (!isVideoFullscreen) {
            return;
        }
        Log.w("EXIT FULLSCREEN");
        activityVideoView.setVisibility(View.GONE);
        activityVideoView.removeView(videoViewContainer);
        activityNonVideoView.setVisibility(View.VISIBLE);
        videoWindow.clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN | WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
        videoViewContainer = null;
        videoCallback.onCustomViewHidden();
        isVideoFullscreen = false;
    }

    public boolean onBackPressed() {
        onHideCustomView();
        return isVideoFullscreen;
    }
  }

WebViewActivity

public class WebViewActivity extends BaseActivity {

    public static final String WEB_VIEW_URL_EXTRA = "URL";
    private boolean loadedFirstURL = true;
    private VideoWebChromeClient mWebChromeClient;

    @Bind(webview)
    WebView mWebView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(provideLayoutId());
        String url = (String) getIntent().getSerializableExtra(WEB_VIEW_URL_EXTRA);

        // Check if URL is YouTube / Vimeo
        if (RegexHelper.isVideoURL(url)){
            // Allow Fullscreen
            final View defaultLayout = findViewById(R.id.defaultLayout);
            final View fullscreenLayout = findViewById(R.id.fullscreenLayout);
            mWebChromeClient = new VideoWebChromeClient(defaultLayout, (ViewGroup) fullscreenLayout, getWindow());
            mWebView.setWebChromeClient(mWebChromeClient);

            // Block external links
            mWebView.setWebViewClient(new WebViewClient() {
                @Override
                public boolean shouldOverrideUrlLoading(WebView view, String url) {
                    if (loadedFirstURL) {
                        loadedFirstURL = false;
                        return false;
                    }
                    return true;
                }
            });
        }
        mWebView.getSettings().setJavaScriptEnabled(true);
        mWebView.loadUrl(url);
    }

        @Override
        public void onBackPressed() {
            if (!mWebChromeClient.onBackPressed())
            {
                if (mWebView.canGoBack()) {
                    mWebView.goBack();
                }
                else {
                    super.onBackPressed();
                }
            }
        }
    }

它在 KitKat 上正常工作，但在 Nougat 上不能正常工作（我只有这两个设备要测试）：当我点击全屏按钮时，它有时会进入全屏，但大多数时候它会“闪烁”并保持非全屏状态。

然后，当它实际上处于全屏模式时，退出全屏的按钮不起作用（根本不调用onHideCustomView）

你可以看到我放了日志，注意到当“flash”发生时，onHideCustomView实际上是在onShowCustomView之后调用的（"ENTER FULLSCREEN"然后立即"EXIT FULLSCREEN"），我不明白为什么。

如果有人能指出我的解决方案，非常感谢

Answer 1

我也遇到了同样的问题，但我花了几个小时解决了这个问题。

您所要做的就是设置 KitKat 设备的 UserAgent 字符串。就是这样！

private String userAgent = "Mozilla/5.0 (Linux; Android 4.4; Nexus 5 Build/_BuildID_) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/30.0.0.0 Mobile Safari/537.36";
mWebView.getSettings().setUserAgentString(userAgent);

这将修复 onShowCustomView() 和 onHideCustomView() 在较新设备上的所有奇怪功能。 希望对您有所帮助。