这就是问题所在：
x1c 0d1x的数据
以下是我在Firebase中设置的规则：

的
Firebase中的当前用户：

的
当我创建一个新用户时，它应该在Firebase Realtime DB中更新。但在这种情况下，这并没有帮助。我甚至将读、写规则改为true，但它没有帮助&一直显示null。

//下面的代码//

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_sign_up)
    supportActionBar?.hide()

    mAuth = FirebaseAuth.getInstance()
    edtName =findViewById(R.id.edt_name)
    edtEmail =findViewById(R.id.edt_email)
    edtPassword =findViewById(R.id.edt_password)
    btnSignUp =findViewById(R.id.btn_signup)

    btnSignUp.setOnClickListener{
        val name = edtName.text.toString()
        val email = edtEmail.text.toString()
        val password = edtPassword.text.toString()

        signUp(name, email,password)

    }
}
private fun signUp(name:String, email: String,password: String){
    //logic for signup

    mAuth.createUserWithEmailAndPassword(email, password)
        .addOnCompleteListener(this) { task ->
            if (task.isSuccessful) {
                //going homE
                addUserToDatabase(name, email, mAuth.currentUser?.uid!!)

                val intent= Intent(this@SignUp, MainActivity::class.java)
                startActivity(intent)

            } else {
                Toast.makeText(this@SignUp, "Some Error occurred", Toast.LENGTH_SHORT).show()

            }
        }

}
private fun addUserToDatabase(name:String, email:String, uid:String){
    mDbRef=FirebaseDatabase.getInstance().getReference()

    mDbRef.child("user").child(uid).setValue(User(name, email, uid))

}

}

字符串
//用户类编码//

package com.example.mychat

class User {
   var name : String? = null
   var email : String? = null
   var uid : String? = null

   constructor(){}

   constructor(name:String?, email:String?, uid:String?){
     this.name= name
     this.email=email
     this.uid=uid
   }

 }

型