Android判断网络是否可用并且开启网络

package com.pocketdigi.webview;




  

import android.app.Activity;

import android.app.AlertDialog;

import android.app.ProgressDialog;

import android.content.Context;

import android.content.DialogInterface;

import android.net.ConnectivityManager;

import android.os.Bundle;

import android.os.Handler;

import android.os.Message;

import android.view.KeyEvent;

import android.webkit.WebChromeClient;

import android.webkit.WebView;

import android.webkit.WebViewClient;

  

 

public class main extends Activity {

    /** Called when the activity is first created. */

    WebView wv;

    ProgressDialog pd;

    Handler handler;

     

    //检测url

    private boolean isOpenNetwork() {

        ConnectivityManager connManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);

        if (connManager.getActiveNetworkInfo() != null) {

        return connManager.getActiveNetworkInfo().isAvailable();

        }

 

 

        return false;

        }

 

    private void initMoreGames() {  

        String URL_MOREGAMES = "http://www.baidu.com";  

        WebView mWebView = (WebView) findViewById(R.id.view_gamesort);  

       

        if (mWebView != null) {  

            mWebView.requestFocus();  

            WebSettings webSettings = mWebView.getSettings();  

            if (webSettings != null) {  

                webSettings.setJavaScriptEnabled(true);  

                webSettings.setCacheMode(MODE_PRIVATE);  

                webSettings.setDefaultTextEncodingName("utf-8");  

            }  

       

            // 判断网络是否可用  

            if(isOpenNetwork() == true) {  

                mWebView.loadUrl(URL_MOREGAMES);  

            } else {  

                AlertDialog.Builder builder = new AlertDialog.Builder(MoreGamesActivity.this);  

                builder.setTitle("没有可用的网络").setMessage("是否对网络进行设置?");  

                   

                builder.setPositiveButton("是", new DialogInterface.OnClickListener() {  

                    @Override  

                    public void onClick(DialogInterface dialog, int which) {  

                        Intent intent = null;  

                           

                        try {  

                            String sdkVersion = android.os.Build.VERSION.SDK;  

                            if(Integer.valueOf(sdkVersion) > 10) {  

                                intent = new Intent(android.provider.Settings.ACTION_WIRELESS_SETTINGS);  

                            }else {  

                                intent = new Intent();  

                                ComponentName comp = new ComponentName("com.android.settings", "com.android.settings.WirelessSettings");  

                                intent.setComponent(comp);  

                                intent.setAction("android.intent.action.VIEW");  

                            }  

                            MoreGamesActivity.this.startActivity(intent);  

                        } catch (Exception e) {  

                            Log.w(TAG, "open network settings failed, please check...");  

                            e.printStackTrace();  

                        }  

                    }  

                }).setNegativeButton("否", new DialogInterface.OnClickListener() {  

                    @Override  

                    public void onClick(DialogInterface dialog, int which) {  

                        dialog.cancel();          

                        finish();  

                    }  

                }).show();  

            }  

        } else {  

            Log.w(TAG, "mWebView is null, please check...");  

        }  

    } 

    //检测url end

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        init();//执行初始化函数

        loadurl(wv,"http://baidu.com ");

    }

     

    public void init(){

        // Progress

        pd=new ProgressDialog(main.this);

        pd.setProgressStyle(ProgressDialog.STYLE_SPINNER);

        pd.setMessage("数据载入中，请稍候！");

        // Show/Hide message

        handler=new Handler(){

        public void handleMessage(Message msg)

        {

            //定义一个Handler，用于处理下载线程与UI间通讯

        if (!Thread.currentThread().isInterrupted())

        {

        switch (msg.what)

        {

        case 0:

        pd.show();//显示进度对话框

        break;

        case 1:

        pd.hide();//隐藏进度对话框，不可使用dismiss()、cancel(),否则再次调用show()时，显示的对话框小圆圈不会动。

        break;

        }

        }

        super.handleMessage(msg);

        }

        };

        // WebView

        wv=(WebView)findViewById(R.id.wv);

        wv.getSettings().setJavaScriptEnabled(true);//可用JS

        wv.setScrollBarStyle(0);//滚动条风格，为0就是不给滚动条留空间，滚动条覆盖在网页上

        wv.setWebViewClient(new WebViewClient(){

        public boolean shouldOverrideUrlLoading(final WebView view, final String url) {

        loadurl(view,url);//载入网页

        return true;

        }//重写点击动作,用webview载入

 

        });

        wv.setWebChromeClient(new WebChromeClient(){

        public void onProgressChanged(WebView view,int progress){//载入进度改变而触发

        if(progress==100){

        handler.sendEmptyMessage(1);//如果全部载入,隐藏进度对话框

        }

        super.onProgressChanged(view, progress);

        }

        });

        }

     

     

    public boolean onKeyDown(int keyCode, KeyEvent event) {//捕捉返回键

        if ((keyCode == KeyEvent.KEYCODE_BACK) && wv.canGoBack()) {   

            wv.goBack();   

            return true;   

        }else if(keyCode == KeyEvent.KEYCODE_BACK){

            ConfirmExit();//按了返回键，但已经不能返回，则执行退出确认

            return true; 

        }   

        return super.onKeyDown(keyCode, event);   

    }

    public void ConfirmExit(){//退出确认

        AlertDialog.Builder ad=new AlertDialog.Builder(main.this);

        ad.setTitle("退出");

        ad.setMessage("是否退出商城?");

        ad.setPositiveButton("是", new DialogInterface.OnClickListener() {//退出按钮

            @Override

            public void onClick(DialogInterface dialog, int i) {

                // TODO Auto-generated method stub

                main.this.finish();//关闭activity

  

            }

        });

        ad.setNegativeButton("否",new DialogInterface.OnClickListener() {

            @Override

            public void onClick(DialogInterface dialog, int i) {

                //不退出不用执行任何操作

            }

        });

        ad.show();//显示对话框

    }

    public void loadurl(final WebView view,final String url){

        new Thread(){

            public void run(){

                handler.sendEmptyMessage(0);

                view.loadUrl(url);//载入网页

            }

        }.start();

    }

  }

本文是小崔从一位大师的评论转载过来的，如果有抄袭清告诫小崔删掉。

小崔最近在做关于这方面的工程，所以为了方便才自己弄下来的。

而且可能有点错误，如有发现请大家指点。