Question

输出未在文本视图和图像中显示我输入toast来查看是否正在showdata中获取数据，但显示为null。

  FirebaseUser user = mAuth.getCurrentUser();
    userid = user.getUid();
    myRef= FirebaseDatabase.getInstance().getReference().child("User").child(userid);
    Toast.makeText(Account.this, myRef.toString(), Toast.LENGTH_SHORT).show();



    myRef.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {


            Showdata(dataSnapshot);
        }

        @Override
        public void onCancelled(@NonNull DatabaseError databaseError) {
            Toast.makeText(Account.this, "Error", Toast.LENGTH_SHORT).show();
        }
    });


 private void Showdata(DataSnapshot dataSnapshot) {


    for(DataSnapshot ds:dataSnapshot.getChildren()) {
        String name = ds.child("name").getValue(String.class);
        String address= ds.child("address").getValue(String.class);
        String contact = ds.child("contact").getValue(String.class);
        String profilepic = ds.child("profilepic").getValue(String.class);

        Toast.makeText(Account.this, name, Toast.LENGTH_SHORT).show();
        //display
        P_name.setText(name);
        P_number.setText(contact);
        P_address.setText(address);
        url = profilepic;
    }


    Glide.with(Account.this /* context */)
            .load(url)
            .into(P_pic);

    progressdialog.dismiss();


}

Firebase数据库

提前谢谢你，天哪！

Answer 1

尝试一下。

myRef.addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
        // You can access the values here, no need to loop. Store it on your custom object, in this case User

        User user = dataSnapshot.getValue(User.class);
        Toast.makeText(Account.this, user.getName(), Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onCancelled(@NonNull DatabaseError databaseError) {
        Toast.makeText(Account.this, "Error", Toast.LENGTH_SHORT).show();
    }
});

Answer 2

从showData方法中删除for循环。由于您已经在用户ID节点中。只需从datasnapshot获取数据即可。

private void Showdata(DataSnapshot dataSnapshot) {

    String name = dataSnapshot.child("name").getValue(String.class);
    String address= dataSnapshot.child("address").getValue(String.class);
    String contact = dataSnapshot.child("contact").getValue(String.class);
    String profilepic = dataSnapshot.child("profilepic").getValue(String.class);

    Toast.makeText(Account.this, name, Toast.LENGTH_SHORT).show();
    //display
    P_name.setText(name);
    P_number.setText(contact);
    P_address.setText(address);
    url = profilepic;
}

使用UID将数据从Firebase存储获取到android studio

2 个答案: