ConnectivityManager判断是否有网络

Java代码



/** 判断是否有网络 */

private boolean checkNetwork() {

boolean flag = false;

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

if (cwjManager.getActiveNetworkInfo() != null)

flag = cwjManager.getActiveNetworkInfo().isAvailable();

if (!flag) {

Builder b = new AlertDialog.Builder(this).setTitle("没有可用的网络").setMessage("请开启GPRS或WIFI网络连接");

b.setPositiveButton("确定", new DialogInterface.OnClickListener() {

public void onClick(DialogInterface dialog, int whichButton) {

Intent mIntent = new Intent("/");

ComponentName comp = new ComponentName("com.android.settings",

"com.android.settings.WirelessSettings");

mIntent.setComponent(comp);

mIntent.setAction("<span class=\"hilite\">android</span>.intent.action.VIEW");

startActivity(mIntent);

}

}).setNeutralButton("取消", new DialogInterface.OnClickListener() {

public void onClick(DialogInterface dialog, int whichButton) {

dialog.cancel();

}

}).create();

b.show();

}



return flag;

}

Android编程获取网络连接状态(3G/Wifi)及调用网络配置界面

http://www.cnblogs.com/mainroadlee/archive/2011/01/11/Android_Network_State_Checking_And_Setting.html

Java代码



/**

* 检测是否开启wify或gprs

* @param context

* @return

*/

public boolean checkNetwork(final Context context){

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



//mobile 3G Data Network

State mobile = manager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState();

//wifi

State wifi = manager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState();



//如果3G网络和wifi网络都未连接，且不是处于正在连接状态 则进入Network Setting界面 由用户配置网络连接

if(mobile==State.CONNECTED||mobile==State.CONNECTING)

return true;

if(wifi==State.CONNECTED||wifi==State.CONNECTING)

return true;





Builder b = new android.app.AlertDialog.Builder(context).setTitle("没有可用的网络").setMessage("请开启GPRS或WIFI网络连接");

b.setPositiveButton("设置网络", new DialogInterface.OnClickListener() {

public void onClick(DialogInterface dialog, int whichButton) {

context.startActivity(new Intent(Settings.ACTION_WIRELESS_SETTINGS));//进入无线网络配置界面

// context.startActivity(new Intent(Settings.ACTION_WIFI_SETTINGS)); //进入手机中的wifi网络设置界面

}

}).setNeutralButton("取消", new DialogInterface.OnClickListener() {

public void onClick(DialogInterface dialog, int whichButton) {

dialog.cancel();

}

}).create();

b.show();

return false;



}

public static boolean checkNet(Context context)
	{
		try
		{
		// 获取手机所有连接管理对象（包括对wi-fi,net等连接的管理） 
		 ConnectivityManager connectivity = (ConnectivityManager) context 
	                .getSystemService(Context.CONNECTIVITY_SERVICE); 
		 
		 if( connectivity!= null )
		 {

			 NetworkInfo info = connectivity.getActiveNetworkInfo();
			 
			 if( info != null && info.isConnected())
			 {
				 // 判断当前网络是否已经连接 
	                if (info.getState() == NetworkInfo.State.CONNECTED) { 
	                    return true; 
	                }
			 }
		 }
		}catch(Exception e)
		{
			return false;
		}
		
		return false;
	}

App自动更新之通知栏下载

http://www.cnblogs.com/qianxudetianxia/archive/2011/04/12/2010919.html