android坑——EditText获取不到值移动开发weixin44735933的博客-

android中通过
studentTextName = (EditText)findViewById(R.id.editaddusername1);
获取到的EditText中输入的值为空

逻辑上感觉似乎没有问题 那么到底是什么问题呢？

将取EditText的值放入对象中的语句放到单击事件函数中就可以获取到EditText中输入的值了
要在点击按钮的同时触发取值的操作

错误代码

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();     } } 

正确代码 将取EditText的值放入对象中的语句放到单击事件函数中

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(); //    } }