更新时间:2023-11-29 16:04:58
首先创建一个如下的界面: b
$ b
public interface IsAvailableCallback {
void onAvailableCallback(boolean isAvailable);
$ b 假设你的上面的代码是在这个方法中,接口对象触发回调:
public void isAvailable(IsAvailableCallback callback){
boolean isAvailable = false;
usernameReference.addListenerForSingleValueEvent(new ValueEventListener(){
@Override $ b $ public void onDataChange(DataSnapshot dataSnapshot){
isAvailable = true;
//这将触发true
callback.onAvailableCallback(isAvailable);
}
$ b $ @Override
public void onCancelled(DatabaseError databaseError){
progressBar.setVisibility(View.GONE);
//这将触发false
callback.onAvailableCallback(isAvailable);
}
});
$ / code>