Android硬件加速以及WebView的onPause,onResume,OnDestroy

MainActivity如下:

package cn.testwebview;
import java.util.Timer;
import java.util.TimerTask;
import android.os.Bundle;
import android.view.View;
import android.view.ViewConfiguration;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.webkit.WebSettings.PluginState;
import android.app.Activity;
import android.graphics.Bitmap;
/**
 * Demo描述:
 * 1 硬件加速的实现
 * 2 WebView的暂停/回复、销毁
 *
 * 参考资料:
 * 1 http://stackoverflow.com/questions/5267639/how-to-safely-turn-webview-zooming-on-and-off-as-needed
 * 2 http://qianxuechao.blog.163.com/blog/static/91813499201292541451358/
 *   Thank you very much
 */
public class MainActivity extends Activity {
    private WebView mWebView;
    private boolean isOnPause = false;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		hardwareAccelerate();
		initWebView();
	}

	//硬件加速
	private void hardwareAccelerate(){
		if (this.getPhoneSDKInt() >= 14) {
			getWindow().setFlags(0x1000000, 0x1000000);
		}
	}

	//设置WebView
	private void initWebView() {
		mWebView = (WebView) findViewById(R.id.webView);
		mWebView.setVerticalScrollBarEnabled(false);
		mWebView.setHorizontalScrollBarEnabled(false);
		mWebView.getSettings().setSupportZoom(true);
		mWebView.getSettings().setBuiltInZoomControls(true);
		mWebView.getSettings().setJavaScriptEnabled(true);

		mWebView.getSettings().setDomStorageEnabled(true);
		mWebView.getSettings().setPluginsEnabled(true);
		mWebView.requestFocus();

		//以下两句和硬件加速有关
		mWebView.getSettings().setPluginState(PluginState.ON);
		mWebView.getSettings().setAllowFileAccess(true); 

		mWebView.getSettings().setUseWideViewPort(true);
		mWebView.getSettings().setLoadWithOverviewMode(true);
		mWebView.getSettings().setCacheMode(WebSettings.LOAD_NO_CACHE);

		mWebView.loadUrl("http://www.cdmetro.cn/");
		mWebView.setWebViewClient(new TestWebViewClient());
	}

	/**
	 * 当Activity执行onPause()时让WebView执行pause
	 */
	@Override
	protected void onPause() {
		super.onPause();
		try {
			if (mWebView != null) {
				mWebView.getClass().getMethod("onPause").invoke(mWebView, (Object[]) null);
				isOnPause = true;
			}

		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	/**
	 * 当Activity执行onResume()时让WebView执行resume
	 */
	@Override
	protected void onResume() {
		super.onResume();
		try {
			if (isOnPause) {
				if (mWebView != null) {
					mWebView.getClass().getMethod("onResume").invoke(mWebView, (Object[]) null);
				}
				isOnPause = false;
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	/**
	 * 该处的处理尤为重要:
	 * 应该在内置缩放控件消失以后,再执行mWebView.destroy()
	 * 否则报错WindowLeaked
	 */
	@Override
	protected void onDestroy() {
		super.onDestroy();
		if (mWebView != null) {
			mWebView.getSettings().setBuiltInZoomControls(true);
			mWebView.setVisibility(View.GONE);
			long delayTime = ViewConfiguration.getZoomControlsTimeout();
			new Timer().schedule(new TimerTask() {
				@Override
				public void run() {
					mWebView.destroy();
					mWebView = null;
				}
			}, delayTime);

		}
		isOnPause = false;
	}

	private class TestWebViewClient extends WebViewClient{
		@Override
		public void onPageStarted(WebView view, String url, Bitmap favicon) {
			super.onPageStarted(view, url, favicon);
		}
		@Override
		public boolean shouldOverrideUrlLoading(WebView view, String url) {
			view.loadUrl(url);
			return true;
		}
		@Override
		public void onPageFinished(WebView view, String url) {
			super.onPageFinished(view, url);

		}
		@Override
		public void onReceivedError(WebView view, int errorCode,String description, String failingUrl) {
			super.onReceivedError(view, errorCode, description, failingUrl);
		}
	}

    public int getPhoneSDKInt() {
		int version = 0;
		try {
			version = Integer.valueOf(android.os.Build.VERSION.SDK);
		} catch (NumberFormatException e) {
			e.printStackTrace();
		}
		return version;
	}
}

main.xml如下:

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
  >

    <WebView
        android:id="@+id/webView"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:text="@string/hello_world"
        android:layout_centerInParent="true"
    />

</RelativeLayout>