기호 '바인딩'오류를 해결할 수 없습니다

Question

그래서 최근에 바인딩을 사용하기 시작했고 내 그라디언트에서 사용할 수있게했지만 시도 할 때 오류가 발생합니까? 나는 gradle 및 프로젝트를 동기화하고 모든 것이 잘되지만 바인딩을 사용하려고하면 "심볼을 바인딩 할 수 없습니다"라는 오류가 발생합니다. 도와주세요!

<?xml version="1.0" encoding="utf-8"?> 
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:app="http://schemas.android.com/apk/res-auto" 
xmlns:tools="http://schemas.android.com/tools" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
app:layout_behavior="@string/appbar_scrolling_view_behavior" 
tools:context="com.example.mike.myapplication.adminScreen" 
tools:showIn="@layout/activity_admin_screen"> 

<EditText 
    android:id="@+id/nameEditText" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:ems="10" 
    android:inputType="textPersonName" 
    android:text="Name" 
    tools:layout_constraintTop_creator="1" 
    android:layout_marginStart="37dp" 
    android:layout_marginTop="31dp" 
    tools:layout_constraintLeft_creator="1" 
    app:layout_constraintLeft_toLeftOf="parent" 
    app:layout_constraintTop_toTopOf="parent" /> 

<EditText 
    android:id="@+id/timeToPrepEditText" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:ems="10" 
    android:inputType="textPersonName" 
    android:text="Time To Prepare" 
    tools:layout_constraintTop_creator="1" 
    tools:layout_constraintRight_creator="1" 
    app:layout_constraintRight_toRightOf="@+id/nameEditText" 
    android:layout_marginTop="20dp" 
    app:layout_constraintTop_toBottomOf="@+id/nameEditText" 
    tools:layout_constraintLeft_creator="1" 
    app:layout_constraintLeft_toLeftOf="@+id/nameEditText" /> 

<EditText 
    android:id="@+id/descEditText" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:ems="10" 
    android:inputType="textPersonName" 
    android:text="Description" 
    tools:layout_constraintTop_creator="1" 
    tools:layout_constraintRight_creator="1" 
    app:layout_constraintRight_toRightOf="@+id/timeToPrepEditText" 
    android:layout_marginTop="7dp" 
    app:layout_constraintTop_toBottomOf="@+id/timeToPrepEditText" 
    tools:layout_constraintLeft_creator="1" 
    app:layout_constraintLeft_toLeftOf="@+id/timeToPrepEditText" /> 

<EditText 
    android:id="@+id/priceEditText" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:ems="10" 
    android:inputType="textPersonName" 
    android:text="Price" 
    tools:layout_constraintTop_creator="1" 
    tools:layout_constraintRight_creator="1" 
    app:layout_constraintRight_toRightOf="@+id/descEditText" 
    android:layout_marginTop="10dp" 
    app:layout_constraintTop_toBottomOf="@+id/descEditText" 
    tools:layout_constraintLeft_creator="1" 
    app:layout_constraintLeft_toLeftOf="@+id/descEditText" /> 

<Button 
    android:id="@+id/addButton" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="Add Item" 
    android:onClick="addButtonClicked" 
    tools:layout_constraintTop_creator="1" 
    android:layout_marginTop="24dp" 
    app:layout_constraintTop_toBottomOf="@+id/priceEditText" 
    tools:layout_constraintLeft_creator="1" 
    app:layout_constraintLeft_toLeftOf="@+id/priceEditText" /> 

<Button 
    android:id="@+id/deleteButton" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="Delete Item" 
    android:onClick="deleteButtonClicked" 
    tools:layout_constraintTop_creator="1" 
    android:layout_marginTop="15dp" 
    app:layout_constraintTop_toBottomOf="@+id/addButton" 
    tools:layout_constraintLeft_creator="1" 
    app:layout_constraintLeft_toLeftOf="@+id/addButton" /> 

<Button 
    android:id="@+id/databaseButton" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="Display Database" 
    android:onClick="dispDatabaseButton" 
    tools:layout_constraintTop_creator="1" 
    android:layout_marginTop="-79dp" 
    app:layout_constraintTop_toBottomOf="@+id/addButton" 
    tools:layout_constraintLeft_creator="1" 
    app:layout_constraintLeft_toLeftOf="@+id/addButton" 
    android:layout_marginLeft="156dp" /> 

<TextView 
    android:id="@+id/myText" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_marginLeft="-41dp" 
    android:layout_marginStart="15dp" 
    android:layout_marginTop="54dp" 
    android:onClick="dispDatabaseButton" 
    android:text="Results" 
    android:textSize="30sp" 
    android:textStyle="bold" 
    app:layout_constraintLeft_toRightOf="@+id/deleteButton" 
    app:layout_constraintTop_toBottomOf="@+id/deleteButton" 
    tools:layout_constraintLeft_creator="1" 
    tools:layout_constraintTop_creator="1" /> 

가 어떻게 내 오류를 수정 않는다 : 이것은 내 XML인가?

여기에 활동 코드가 있습니다. 제 경우에는 기본 기본 활동이 아니라 AdminScreen입니다. 당신은 데이터 바인딩 라이브러리를 의미하는 경우

public class adminScreen extends AppCompatActivity { 



@Override 
protected void onCreate(Bundle savedInstanceState) { 


    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_admin_screen); 




} 

private void saveToDB() { 
    SQLiteDatabase database = new DBSQLiteHelper(this).getWritableDatabase(); 

    ContentValues values = new ContentValues(); 
    values.put(Menu.MenuItems.COLUMN_NAME, binding.nameEditText.getText().toString()); 
    values.put(Menu.MenuItems.COLUMN_PREP, binding.timeToPrepEditText.getText().toString()); 
    values.put(Menu.MenuItems.COLUMN_DESCRIPTION, binding.descEditText.getText().toString()); 
    values.put(Menu.MenuItems.COLUMN_PRICE, binding.priceEditText.getText().toString()); 

    long newRowId = database.insert(Menu.MenuItems.TABLE_NAME, null, values); 

    Toast.makeText(this, "The new Row Id is " + newRowId, Toast.LENGTH_LONG).show(); 
    } 

} 

Answer 1

당신은 당신이

<?xml version="1.0" encoding="utf-8"?> 
<layout xmlns:android="http://schemas.android.com/apk/res/android"> 
    <data> 
     <variable name="user" type="com.example.User"/> 
    </data> 
    <LinearLayout 
     android:orientation="vertical" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent"> 
     <TextView android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:text="@{user.firstName}"/> 
     <TextView android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:text="@{user.lastName}"/> 
    </LinearLayout> 
</layout>