Android中判断网络是否连接并提示设置

/**
	 * 判断网络是否连通
	 * @param context
	 * @return
	 */
	public static boolean isNetworkConnected(Context context){
		ConnectivityManager cm = (ConnectivityManager) context.getSystemService(context.CONNECTIVITY_SERVICE);
		NetworkInfo info = cm.getActiveNetworkInfo();
		return info != null && info.isConnected();	
	}

弹出对话框并设置

//如果网络连接
				if(Util.isNetworkConnected(context)){
					mMainFrameTask = new MainFrameTask();
					mMainFrameTask.execute();
				}else{
					AlertDialog.Builder builder = new Builder(context);
					builder.setTitle("设置网络");
					builder.setMessage("网络错误，请设置网络");
					
					builder.setPositiveButton("设置网络",new DialogInterface.OnClickListener() {
						
						@Override
						public void onClick(DialogInterface dialog, int which) {
							//获取系统版本号
							/* Build.VERSION_CODES
							    1 (0x00000001)           Android 1.0             BASE
							    2 (0x00000002)           Android 1.1             BASE_1_1
							    3 (0x00000003)           Android 1.5             CUPCAKE
							    4 (0x00000004)           Android 1.6             DONUT
							    5 (0x00000005)           Android 2.0             ECLAIR
							    6 (0x00000006)           Android 2.0.1          ECLAIR_0_1
							    7 (0x00000007)           Android 2.1             ECLAIR_MR1
							    8 (0x00000008)           Android 2.2             FROYO
							    9 (0x00000009)           Android 2.3             GINGERBREAD
							    10 (0x0000000a)         Android 2.3.3          GINGERBREAD_MR1
							    11 (0x0000000b)         Android 3.0             HONEYCOMB
							    12 (0x0000000c)         Android 3.1             HONEYCOMB_MR1
							    13 (0x0000000d)         Android 3.2             HONEYCOMB_MR2 */
							int currentapiVersion=android.os.Build.VERSION.SDK_INT;
							System.out.println("currentapiVersion = " + currentapiVersion);
							Intent intent;
							if(currentapiVersion < 11){
								intent = new Intent();
								intent.setClassName("com.android.settings", "com.android.settings.WirelessSettings");
							}else{
								//3.0以后
								//intent = new Intent( android.provider.Settings.ACTION_WIRELESS_SETTINGS);
								intent = new Intent( android.provider.Settings.ACTION_SETTINGS);
							}
							context.startActivity(intent);
						}
					});
					builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
						
						@Override
						public void onClick(DialogInterface dialog, int which) {
							
						}
					});
					builder.create().show();
				}
			}

注意：3.0以前和3.0以后的设置网络方法不同。