Android - Media Player is null on Webview Pause/Resume Sound ครับ

	private String _rootUrl;
	private String _url;
	WebView _webView;
	MediaPlayer _mediaPlayer;
	MediaPlayerControl mediaPlayerController;
	Context _context;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		_url = "http://tkapp.tkpark.or.th/stocks/content/developer1/thaimusic/25_sorduang/mobile/";
		_webView = (WebView) findViewById(R.id.webView);
		_webView.setWebViewClient(new WebViewClient());
		_webView.getSettings().setAllowFileAccess(true);
		_webView.getSettings().setJavaScriptEnabled(true);
		_webView.loadUrl(_url);
		
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}

	@SuppressLint("NewApi")
	@Override
	protected void onPause() {
		Log.v("Test4 Log", "WEBVIEW : onBackPress Pause");
		super.onPause();
		{
			try {
				Class.forName("android.webkit.WebView").getMethod("onPause", (Class[]) null).invoke(_webView, (Object[]) null);
			} catch (Exception e) {
				Log.v("Test4 Log", "WEBVIEW Error on Puase");
			}
		}
	}

	@Override
	protected void onResume() {
		Log.v("Test4 Log", "WEBVIEW : onBackPress Resume");
		super.onResume();
		{
			try {
				Class.forName("android.webkit.WebView").getMethod("onResume", (Class[]) null).invoke(_webView, (Object[]) null);
			} catch (Exception e) {
				Log.v("Test4 Log", "WEBVIEW Error on Resume");
			}
		}
	}