Android pit-EditText can't get value

FindTextById (R.id.editaddusername1); the
input value in the EditText obtained by studentTextName = (EditText) in Android is empty

It seems logically that there is no problem. So what is the problem?

Put the statement that takes the value of EditText into the object and put it in the click event function to get the value entered in the EditText.
To trigger the value operation when the button is clicked

error code

package com.example.databack;

import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.EditText;

import androidx.appcompat.app.AppCompatActivity;

import com.example.databack.entity.FamilyNumber;
import com.example.databack.entity.StudentNumber;
import com.example.databack.entity.TeacherNumber;

public class AddActivity extends AppCompatActivity {
    private EditText studentTextName , studentTextPhon;
    private EditText teacherTextName , teacherTextPhon;
    private EditText fimallyTextName , fimallyTextPhon;
    private TeacherNumber teachers;
    private StudentNumber students;
    private FamilyNumber famillys;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_add);

        studentTextName = (EditText)findViewById(R.id.editaddusername1);
        studentTextPhon = (EditText)findViewById(R.id.editaddphon1);

        fimallyTextName  = (EditText) findViewById(R.id.editaddusername2);
        fimallyTextPhon = (EditText) findViewById(R.id.editaddphon2);

        teacherTextName = (EditText) findViewById(R.id.editaddusername3);
        teacherTextPhon = (EditText) findViewById(R.id.editaddphon3);

//将EditText中写入的值获取到同时放入对象中
        teachers = new TeacherNumber(teacherTextName.getText().toString() ,  teacherTextPhon.getText().toString());

        students = new StudentNumber(studentTextName.getText().toString() , studentTextPhon.getText().toString());

        famillys = new FamilyNumber(fimallyTextName.getText().toString() , fimallyTextPhon.getText().toString());
    }

//点击事件实现函数
    public void addTeacher(View view) {

        Intent intent = new Intent();
        intent.putExtra("teacher" , teachers);
        setResult(1 , intent);
        finish();
    }
}

The correct code will put the value of EditText into the object into the click event function

package com.example.databack;

import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.EditText;

import androidx.appcompat.app.AppCompatActivity;

import com.example.databack.entity.FamilyNumber;
import com.example.databack.entity.StudentNumber;
import com.example.databack.entity.TeacherNumber;

public class AddActivity extends AppCompatActivity {
    private EditText studentTextName , studentTextPhon;
    private EditText teacherTextName , teacherTextPhon;
    private EditText fimallyTextName , fimallyTextPhon;
    private TeacherNumber teachers;
    private StudentNumber students;
    private FamilyNumber famillys;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_add);

        studentTextName = (EditText)findViewById(R.id.editaddusername1);
        studentTextPhon = (EditText)findViewById(R.id.editaddphon1);

        fimallyTextName  = (EditText) findViewById(R.id.editaddusername2);
        fimallyTextPhon = (EditText) findViewById(R.id.editaddphon2);

        teacherTextName = (EditText) findViewById(R.id.editaddusername3);
        teacherTextPhon = (EditText) findViewById(R.id.editaddphon3);


    }

    public void addTeacher(View view) {

//取值存入对象中的语句移到了这里
        teachers = new TeacherNumber(teacherTextName.getText().toString() ,  teacherTextPhon.getText().toString());

        students = new StudentNumber(studentTextName.getText().toString() , studentTextPhon.getText().toString());

        famillys = new FamilyNumber(fimallyTextName.getText().toString() , fimallyTextPhon.getText().toString());
        //老师  1
        Intent intent = new Intent();
        intent.putExtra("teacher" , teachers);
        setResult(1 , intent);
        finish();
    }
//
//    public void addFamily(View view) {
//        //家人   2
//        intent.putExtra("student" , students);
//        setResult(2 , intent);
//        finish();
//    }
//
//    public void addStudent(View view) {
//        //学生   3
//        intent.putExtra("fimally" , famillys);
//        setResult(3 , intent);
//        finish();
//    }
}