android UI控件之webview控件使用实例：加载网页到webview中

package com.vincent.org.networkapp;

import android.app.Activity;
import android.app.ProgressDialog;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Button;
import android.widget.EditText;

public class WebViewActivity extends Activity implements OnClickListener {

    private EditText url;
    private Button loadurl;
    private Button loaddata;
    private WebView webView;
    private ProgressDialog dialog;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);// 开启进度条功能
        setContentView(R.layout.activity_web_view);

        setProgressBarIndeterminate(true);// 是的进度条可见
        url = (EditText) findViewById(R.id.webview_et);
        loaddata = (Button) findViewById(R.id.loaddata_btn);
        loadurl = (Button) findViewById(R.id.loadurl_btn);
        webView = (WebView) findViewById(R.id.webview_view);
        webView.getSettings().setJavaScriptEnabled(true);// 开启对javascript支持
        webView.getSettings().setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK);//开启缓存
        webView.setFocusable(true);
        webView.setWebViewClient(new WebViewClient() {

            @Override
            // 覆盖WebView默认使用第三方或系统默认浏览器打开网页的行为，使网页用WebView打开
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                // TODO Auto-generated method stub
                view.loadUrl(url);
// 返回值是true的时候控制去WebView打开，为false调用系统浏览器或第三方浏览器
                return true;
            }
        });
        webView.setWebChromeClient(new WebChromeClient() {
            // 当进度发送改变时候回调这个方法
            @Override
            public void onProgressChanged(WebView view, int newProgress) {
                 //当加载完毕时候，关闭对话框
                if (newProgress == 100) {

                    closeDialog();
                } else {
openDialog(newProgress);//实时提示下载进度
                }
                super.onProgressChanged(view, newProgress);

            }

        });
        loaddata.setOnClickListener(this);
        loadurl.setOnClickListener(this);
    }

    private void closeDialog() {
        // TODO Auto-generated method stub

        if (dialog != null && dialog.isShowing()) {
            dialog.dismiss();
            dialog = null;

        }
    }

    private void openDialog(int newProgress) {
        // TODO Auto-generated method stub

        if (dialog == null) {
            dialog = new ProgressDialog(this);
            dialog.setTitle("正在加载");
            dialog.setProgress(newProgress);
            dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
            dialog.show();
        } else {
            dialog.setProgress(newProgress);
        }
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        // TODO Auto-generated method stub
        // 如果这个事件是后退的返回事件
        if (keyCode == KeyEvent.KEYCODE_BACK) {

            if (webView.canGoBack()) {
                webView.goBack();
                return true;
            } else {
                System.exit(0);
            }

        }
        return super.onKeyDown(keyCode, event);
    }
    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        String urlString = url.getText().toString();
        switch (v.getId()) {
        //加载由data构造的数据构成的url
        case R.id.loaddata_btn:

            String data = "baidu";
            webView.loadData(data, "text/html", "utf-8");
            //
            break;

        case R.id.loadurl_btn:
            // 加载制定的url对于的网页
            webView.loadUrl(urlString);
            break;
        default:
            break;
        }
    }
}

webview布局文件

<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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.vincent.org.networkapp.WebViewActivity" >

   <LinearLayout
       android:layout_height="wrap_content"
       android:layout_width="match_parent"
       android:layout_alignParentTop="true"
       android:id="@+id/listview_tv" 
       android:orientation="vertical"
       >
        <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="20sp"
        android:text="@string/inpuinternetaddress" />
        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/webview_et"
            android:text="http://www.baidu.com" />
   LinearLayout>

    <LinearLayout
       android:layout_height="wrap_content"
       android:layout_width="match_parent"
       android:layout_below="@id/listview_tv"
       android:id="@+id/listview_btn"
       android:orientation="horizontal"
       >
       <Button android:layout_width="0dp"
           android:layout_height="wrap_content"
           android:layout_weight="1"
           android:id="@+id/loadurl_btn"
           android:text="@string/loadUrl"/>
        <Button android:layout_width="0dp"
           android:layout_height="wrap_content"
           android:layout_weight="1"
           android:id="@+id/loaddata_btn"
           android:text="@string/loadData"/>
   LinearLayout>
<WebView 
    android:layout_below="@id/listview_btn"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:id="@+id/webview_view"
    android:layout_width="match_parent"/>
RelativeLayout>

用到的字符串资源

 
    <string name="inpuinternetaddress">请输入网址string>
    <string name="loadUrl">loadUrlstring>
    <string name="loadData">loadDatastring>
    <string name="webview">webviewstring>

记得加网络访问权限

    <uses-permission android:name="android.permission.INTERNET" />