if (isConnect(this)==false) {
			final AlertDialog dlg = new AlertDialog.Builder(this).create();
			dlg.show();
			Window window = dlg.getWindow();
			window.setContentView(R.layout.shrew_exit_dialog);
			TextView title = (TextView) window.findViewById(R.id.title);
			title.setText("请开启网络连接！");

			Button ok = (Button) window.findViewById(R.id.btn_ok);
			ok.setOnClickListener(new View.OnClickListener() {
				public void onClick(View v) {
					Intent intent = new Intent("android.settings.WIRELESS_SETTINGS");
					startActivityForResult(intent, 0); // 此为设置完成后返回到获取界面
					dlg.cancel();
				}
			});

			Button cancel = (Button) window.findViewById(R.id.btn_cancel);
			cancel.setOnClickListener(new View.OnClickListener() {
				public void onClick(View v) {
					finish();
				}
			});
		}

	public static boolean isConnect(Context context) { 
		// 获取手机所有连接管理对象（包括对wi-fi,net等连接的管理） 
		try { 
			ConnectivityManager connectivity = (ConnectivityManager) context 
					.getSystemService(Context.CONNECTIVITY_SERVICE); 
			if (connectivity != null) { 
				// 获取网络连接管理的对象 
				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) { 
			//TODO: handle exception 
			Log.v("error",e.toString()); 
		} 
		return false; 
	} 

判断网络连接并跳到设置界面