Android使用WebView浏览网页

webview.xml

<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#fff" >
<ProgressBar
android:layout_width="match_parent"
android:layout_height="5dp"
android:layout_gravity="center"
android:visibility="visible"
style="?android:attr/progressBarStyleHorizontal"
android:progressDrawable="@drawable/horizontal_progress"
android:id="@+id/progress_bar" />

<WebView
android:id="@+id/webview"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
</LinearLayout>WebViewActivity.java

import java.util.Timer;
import java.util.TimerTask;

import android.app.Activity;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.KeyEvent;
import android.view.View;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.ProgressBar;

public class WebViewActivity extends Activity {
WebView webView;
String urlPath = "http://www.baidu.com";
private long timeout = 12000;
private Timer timer;

ProgressBar progressBar;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.webview);
progressBar = (ProgressBar)findViewById(R.id.progress_bar);

webView =(WebView) findViewById(R.id.webview);
webView.getSettings().setAllowFileAccess(true);
webView.getSettings().setJavaScriptEnabled(true);
webView.getSettings().setDefaultTextEncodingName("UTF-8") ;
//设置加载进来的页面自适应手机屏幕
//		webView.getSettings().setUseWideViewPort(true);
//		webView.getSettings().setLoadWithOverviewMode(true);

webView.requestFocus();
webView.loadUrl(urlPath);

WebSettings mWebSettings = webView.getSettings();
mWebSettings.setBuiltInZoomControls(true);
mWebSettings.setSupportZoom(true);

webView.setWebViewClient(new MyWebViewClient());
webView.setWebChromeClient(new MyWebChromeClient());
}

@Override
protected void onDestroy() {
super.onDestroy();
if(timer != null){
timer.cancel();
}

}

class MyWebViewClient extends WebViewClient{
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
super.onPageStarted(view, url, favicon);
TimerTask timerTask = new TimerTask() {
@Override
public void run() {
//超时后,首先判断页面加载进度,超时并且进度小于100,就执行超时后的动作
if (WebViewActivity.this.webView.getProgress() < 100) {
Message msg = new Message();
msg.what = 1;
mHandler.sendMessage(msg);
timer.cancel();
timer.purge();
}
}
};
if(timer == null){
timer = new Timer();
timer.schedule(timerTask, timeout, 1);
}
}

@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
if(url.indexOf("tel:")<0){
view.loadUrl(url);
}
return super.shouldOverrideUrlLoading(view, url);
}
@Override
public void onReceivedError(WebView view, int errorCode,
String description, String failingUrl) {
super.onReceivedError(view, errorCode, description, failingUrl);
webView.loadDataWithBaseURL(null, "<br><br><br><br><center><h1>未能打开网页,请稍后重试!</h1></center>", "text/html", "UTF-8", null);
}

@Override
public void onPageFinished(WebView view, String url) {
super.onPageFinished(view, url);
/**
* onPageFinished指页面加载完成,完成后取消计时器
*/
if(timer != null){
timer.cancel();
timer.purge();
}
}
}

private Handler mHandler = new Handler(){
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
if(msg.what == 1){
progressBar.setVisibility(View.GONE);
webView.loadDataWithBaseURL(null, "<br><br><br><br><center><h3>未能打开网页,请稍后重试!</h3></center>", "text/html", "UTF-8", null);
}
}
};

public class MyWebChromeClient extends android.webkit.WebChromeClient {
@Override
public void onProgressChanged(WebView view, int newProgress) {
try {
if (newProgress == 100) {
progressBar.setVisibility(View.GONE);
} else {
if (progressBar.getVisibility() == View.GONE){
progressBar.setVisibility(View.VISIBLE);
}
progressBar.setProgress(newProgress);
}

} catch (Exception e) {
}
super.onProgressChanged(view, newProgress);
}
}

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if ((keyCode == KeyEvent.KEYCODE_BACK) && webView.canGoBack()){
//返回键退回
webView.goBack();
return true;
}
return super.onKeyDown(keyCode, event);
}
}