从Firebase数据库加载数据时显示进度

Question

I want show progress while data is loaded. It works well. But only once. If I press back and again, error occurs. Searched everywhere, tried everything. Please help.

Working code.

 a.showProgressDialog();

        mUsersDatabaseReference.addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                        a.hideProgressDialog();
            }

            @Override
            public void onCancelled(DatabaseError databaseError) {
            }

        });

update . here is error code I got.

Unable to add window -- token android.os.BinderProxy@41ea89e0 is not valid; is your activity running?

Tried. Count pairs show -- dissmiss. Equal. Not helped. Tried. Make showProgress not static. Not helped. ll try put dissmiss on ui thread? Should help. Update later.

Answer 1

showProgressDialog method was like this.

  public void showProgressDialog() {
    if (mProgressDialog == null) {
        mProgressDialog = new ProgressDialog(a);
        mProgressDialog.setMessage("Loading...");
        mProgressDialog.setIndeterminate(true);
    }

    if (!a.isFinishing()) {
        mProgressDialog.show();
    }

}

After testing and going deep into it I found the problem. As it was in preference activity and fragments was static, this method added was also static. Later I decided this might be bad, and moved it to not static.

It does not helped at a glance, but after a break I looked again and found that mProgressDialog variable was still static. Changed it to none-static and that solved my crash.

Thanks all for help.