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;

}

}

//该代码片段来自于: http://www.sharejs.com/codes/java/7814

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>

//该代码片段来自于: http://www.sharejs.com/codes/java/7814