无网络连接 弹出框

//

//获取手机连接

ConnectivityManager manager = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE);

//获取网络信息

NetworkInfo info = manager.getActiveNetworkInfo();

//判断

if(info ==null){

AlertDialog.Builder builder =newAlertDialog.Builder(MainActivity.this);

builder.setTitle("提示？");

builder.setMessage("是否跳转到设置");

builder.setPositiveButton("确定",newAlertDialog.OnClickListener() {

@Override

public voidonClick(DialogInterface dialogInterface,inti) {

startActivity(newIntent(android.provider.Settings.ACTION_WIFI_SETTINGS));

}

});

builder.setNegativeButton("取消",null);

AlertDialog dialog = builder.create();

dialog.show();

}else{

Toast.makeText(MainActivity.this,"连接成功？",Toast.LENGTH_SHORT).show();

}

}