应用的Activity中有一个布局文件和ProgressBar:
public class Saldo_Menu extends Activity implements OnClickListener, OnLongClickListener {
static InternetHelper IH;
ProgressBar pleasewait;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
pleasewait=(ProgressBar)findViewById(R.id.pleasewait);
IH=new InternetHelper(this);
pleasewait.setVisibility(View.INVISIBLE);
}
我想从这个辅助类InternetHelper
中激活progressbar
,不知道怎么做? 现在的出现空指针,我知道不能从这里访问UI:
public InternetHelper (Context context) {
myContext = context;
}
public void ShowProgressBar(boolean show){
if (show){pleasewait.setVisibility(View.VISIBLE);}else{pleasewait.setVisibility(View.INVISIBLE);}
}